Decision tables: Difference between revisions
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{{draft task}}
{{Wikipedia|Decision Table|en}}<br>
[[wp:Decision_table|Decision Tables]] are a precise yet compact way to model complicated logic.
;Task:
Demonstrate how your language implements decision tables.
Use this [[wp:Decision_table#Example|example]] of Printer Troubleshooting given in the Wikipedia article.
<br><br>
=={{header|11l}}==
{{trans|Kotlin}}
<syntaxhighlight lang="11l">V conditions = [
(‘Printer prints’ , ‘NNNNYYYY’),
(‘A red light is flashing’ , ‘YYNNYYNN’),
(‘Printer is recognized by computer’, ‘NYNYNYNY’)]
V actions = [
(‘Check the power cable’ , ‘NNYNNNNN’),
(‘Check the printer-computer cable’ , ‘YNYNNNNN’),
(‘Ensure printer software is installed’, ‘YNYNYNYN’),
(‘Check/replace ink’ , ‘YYNNNYNN’),
(‘Check for paper jam’ , ‘NYNYNNNN’)]
V nr = conditions[0][1].len
V np = 7
print(‘Please answer the following questions with a y or n:’)
[Bool] answers
L(condition) conditions
V inp = ‘’
L
inp = input(‘ ’condition[0]‘ ? ’).uppercase()
I inp C (‘Y’, ‘N’)
L.break
answers.append(inp == ‘Y’)
print("\nRecommended action(s):")
L(r) 0 .< nr
L(c) 0 .< conditions.len
V yn = I answers[c] {‘Y’} E ‘N’
I conditions[c][1][r] != yn
L.break
L.was_no_break
I r == np
print(‘ None (no problem detected)’)
E
L(action) actions
I action[1][r] == ‘Y’
print(‘ ’action[0])
L.break</syntaxhighlight>
{{out}}
<pre>
Please answer the following questions with a y or n:
Printer prints ? n
A red light is flashing ? n
Printer is recognized by computer ? n
Recommended action(s):
Check the power cable
Check the printer-computer cable
Ensure printer software is installed
</pre>
=={{header|Ada}}==
First the specification of a generic decision table package:
<syntaxhighlight lang="ada">generic
type Condition is (<>);
type Action is (<>);
with function Ask_Question (Cond: Condition) return Boolean;
with procedure Give_Answer (Act: Action);
with procedure No_Answer;
package Generic_Decision_Table is
type Answers is array(Condition) of Boolean;
type Rule_R is record
If_Then: Answers;
Act: Action;
end record;
type Rule_A is array(Positive range <>) of Rule_R;
procedure React(Rules: Rule_A);
end Generic_Decision_Table;
</syntaxhighlight>
Next, the implementation of the generic decision table package:
<syntaxhighlight lang="ada">package body Generic_Decision_Table is
procedure React(Rules: Rule_A) is
A: Answers;
Some_Answer: Boolean := False;
begin
for C in A'Range loop
A(C) := Ask_Question(C);
end loop;
for R in Rules'Range loop
if A = Rules(R).If_Then then
Give_Answer(Rules(R).Act);
Some_Answer := True;
end if;
end loop;
if not Some_Answer then
No_Answer;
end if;
end React;
end Generic_Decision_Table;
</syntaxhighlight>
That was easy! Now we implement the printer troubleshooting application:
<syntaxhighlight lang="ada">with Generic_Decision_Table, Ada.Text_IO;
procedure Printer_Decision_Table is
type Condition is (Does_Not_Print, Red_Light_Flashing, Unrecognised);
type Action is (Power_Cable, Printer_Computer_Cable, Software_Installed,
New_Ink, Paper_Jam);
function Question(Cond: Condition) return Boolean is
use Ada.Text_IO;
Ch: Character;
begin
case Cond is
when Does_Not_Print =>
Put("Printer does not print?");
when Red_Light_Flashing =>
Put("A red light is flashing?");
when Unrecognised =>
Put("Printer is unrecognised?");
end case;
Put_Line (" y/Y => 'yes', any other input: 'no'");
Get(Ch);
return (Ch='y') or (Ch='Y');
end Question;
procedure Answer(Act: Action) is
use Ada.Text_IO;
begin
case Act is
when Power_Cable =>
Put_Line("Check the power cable!");
when Printer_Computer_Cable =>
Put_Line("Check the printer-computer cable!");
when Software_Installed =>
Put_Line("Ensure the printer software is installed!");
when New_Ink =>
Put_Line("Check/replace ink!");
when Paper_Jam =>
Put_Line("Check for paper jam!");
end case;
end Answer;
procedure No_Answer is
begin
Ada.Text_IO.Put_Line("Sorry! I have no idea what to do now!");
end No_Answer;
package DT is new Generic_Decision_Table
(Condition, Action, Question, Answer, No_Answer);
R: DT.Rule_A := (((True, False, True), Power_Cable),
((True, True, True), Printer_Computer_Cable),
((True, False, True), Printer_Computer_Cable),
((True, True, True), Software_Installed),
((True, False, True), Software_Installed),
((False, True, True), Software_Installed),
((False, False, True), Software_Installed),
((True, True, True), New_Ink),
((True, True, False), New_Ink),
((False, True, True), New_Ink),
((False, True, False), New_Ink),
((True, True, False), Paper_Jam),
((True, False, False), Paper_Jam)
);
begin
DT.React(R);
end Printer_Decision_Table;</syntaxhighlight>
Sample output:
<pre>> ./printer_decision_table
Printer does not print? y/Y => 'yes', any other input: 'no'
y
A red light is flashing? y/Y => 'yes', any other input: 'no'
n
Printer is unrecognised? y/Y => 'yes', any other input: 'no'
n
Check for paper jam!
> ./printer_decision_table
Printer does not print? y/Y => 'yes', any other input: 'no'
y
A red light is flashing? y/Y => 'yes', any other input: 'no'
y
Printer is unrecognised? y/Y => 'yes', any other input: 'no'
n
Check/replace ink!
Check for paper jam!
> ./printer_decision_table
Printer does not print? y/Y => 'yes', any other input: 'no'
n
A red light is flashing? y/Y => 'yes', any other input: 'no'
n
Printer is unrecognised? y/Y => 'yes', any other input: 'no'
n
Sorry! I have no idea what to do now!</pre>
=={{header|AutoHotkey}}==
<syntaxhighlight lang="autohotkey">Conditions =
(
Printer does not print |Y|Y|Y|Y|N|N|N|N|
A red light is flashing |Y|Y|N|N|Y|Y|N|N|
Printer is unrecognized |Y|N|Y|N|Y|N|Y|N|
)
Actions=
(
Check the power cable | | |x| | | | | |
Check the printer-computer cable |x| |x| | | | | |
Ensure printer software is installed |x| |x| |x| |x| |
Check/replace ink |x|x| | |x|x| | |
Check for paper jam | |x| |x| | | | |
)
Condition:=[], Action:=[], Correlation:=[]
loop, parse, Conditions, `n
{
No:= A_Index, RegExMatch(A_LoopField, "^(.*?)\t+(.*)", m), Cond%No% := m1
for k, v in StrSplit(m2, "|")
Condition[No, k] := v="Y"?1:0
}
loop, parse, Actions, `n
{
No:= A_Index , RegExMatch(A_LoopField, "^(.*?)\t+(.*)", m), Act%No% := m1
for k, v in StrSplit(m2, "|")
Action[No, A_Index] := v="X"?1:0
}
loop, % Condition[1].MaxIndex()
{
j := A_Index, CondLine:=ActLine:=""
loop, % Condition.MaxIndex()
CondLine .= Condition[A_Index,j]
loop, % Action.MaxIndex()
ActLine.= Action[A_Index,j]?1:0
Correlation[CondLine]:=ActLine
}
Gui, font,, Courier
Gui, add, text, w456
Gui, add, text, wp h1 0x7 y+0
loop, parse, Conditions, `n
{
Gui, add, text, y+0 , % A_LoopField
Gui, add, text, wp h1 0x7 y+0
}
Gui, add, text, wp
Gui, add, text, wp h1 0x7 y+0
loop, parse, Actions, `n
{
Gui, add, text, y+0 , % A_LoopField
Gui, add, text, wp h1 0x7 y+0
}
Gui, add, text, wp
loop, % Condition.MaxIndex()
Gui, add, Checkbox,vC%A_Index% gSubmit wp h15, % Cond%A_Index%
Gui, add, text, wp , take the following actions(s):
AM := Action.MaxIndex()
Gui, add, Edit, vOutput ReadOnly r%AM% wp -TabStop
Gui, show
return
Submit:
Gui, Submit, NoHide
CondLine:=Res:=""
loop, % Condition.MaxIndex()
CondLine.= C%A_Index%
MyCorr := Correlation[CondLine]
loop, parse, MyCorr
if A_LoopField
Res .= Act%A_Index% "`n"
GuiControl,, Output, % Res
return</syntaxhighlight>
=={{header|AWK}}==
<syntaxhighlight lang="awk">
# syntax: GAWK -f DECISION_TABLES.AWK DECISION_TABLES.TXT
BEGIN {
FS = ":"
}
{ if ($0 ~ /^#/) { # comment
next
}
if (rule_length == 0) { # 1st rule
rule_length = length($2)
}
if (rule_length != length($2)) {
error(sprintf("FILENAME=%s, FNR=%d, rule length not consistent with previous lengths, %s",FILENAME,FNR,$0))
}
if ($1 == "C") { # condition
if ($2 !~ /^[NY]+$/) {
error(sprintf("FILENAME=%s, FNR=%d, rule S/B 'N' or 'Y', %s",FILENAME,FNR,$0))
}
c_arr[++c] = $2 SUBSEP $3
}
else if ($1 == "A") { # action
if ($2 !~ /^[X-]+$/) {
error(sprintf("FILENAME=%s, FNR=%d, rule S/B 'X' or '-', %s",FILENAME,FNR,$0))
}
a_arr[++a] = $2 SUBSEP $3
}
}
END {
validate_rules()
if (errors > 0) { exit(1) }
show_actions(ask_conditions())
exit(0)
}
function ask_conditions( ans,i,key) {
print("condtions:")
for (i=1; i<=c; i++) {
while (1) {
printf(" %s? ",getext(c_arr[i]))
getline ans <"con"
if (ans ~ /^[nNyY]/) {
key = key toupper(substr(ans,1,1))
break
}
}
}
return(key)
}
function getext(str) {
return(substr(str,index(str,SUBSEP)+1))
}
function show_actions(user_reply, hits,i,key) {
key = key_arr[user_reply]
print("actions:")
for (i=1; i<=a; i++) {
if (substr(a_arr[i],key,1) == "X") {
printf(" %s\n",getext(a_arr[i]))
hits++
}
}
printf("%d found\n",hits)
}
function validate_rules( i,j,key) {
for (i=1; i<=rule_length; i++) {
key = ""
for (j=1; j<=c; j++) {
key = key substr(c_arr[j],i,1)
}
if (key in key_arr) {
error(sprintf("duplicate key: %s",key))
}
key_arr[key] = i
}
}
function error(message) {
printf("error: %s\n",message)
errors++
return
}
</syntaxhighlight>
<p>decision table:</p>
<pre>
# RULES CONDITIONS
C:YYYYNNNN:Printer does not print
C:YYNNYYNN:A red light is flashing
C:YNYNYNYN:Printer is unrecognized
# RULES ACTIONS
A:--X-----:Check the power cable
A:X-X-----:Check the printer-computer cable
A:X-X-X-X-:Ensure printer software is installed
A:XX--XX--:Check/replace ink
A:-X-X----:Check for paper jam
</pre>
<p>Output:</p>
<pre>
condtions:
Printer does not print? Y
A red light is flashing? Y
Printer is unrecognized? Y
actions:
Check the printer-computer cable
Ensure printer software is installed
Check/replace ink
3 found
condtions:
Printer does not print? N
A red light is flashing? N
Printer is unrecognized? N
actions:
0 found
</pre>
=={{header|C}}==
With flaky keyboard input:<syntaxhighlight lang="c">#include <stdio.h>
#define N_COND 3
#define COND_LEN (1 << N_COND)
struct { const char *str, *truth;}
cond[N_COND] = {
{"Printer does not print", "1111...."},
{"A red light is flashing", "11..11.."},
{"Printer is unrecognised", "1.1.1.1."},
},
solu[] = {
{"Check the power cable", "..1....."},
{"Check the printer-computer cable", "1.1....."},
{"Ensure printer software is installed","1.1.1.1."},
{"Check/replace ink", "11..11.."},
{"Check for paper jam", ".1.1...."},
};
int main()
{
int q, ans, c;
for (q = ans = c = 0; q < N_COND; q++) {
do {
if (c != '\n') printf("%s? ", cond[q].str);
c = getchar();
} while (c != 'y' && c != 'n');
ans = (ans << 1) | (c != 'y');
}
if (ans == COND_LEN - 1)
printf("\nSo, you don't have a problem then?\n");
else {
printf("\nSolutions:\n");
for (q = 0; q < sizeof(solu)/sizeof(solu[0]); q++)
if (solu[q].truth[ans] == '1')
printf(" %s\n", solu[q].str);
}
return 0;
}</syntaxhighlight>output<syntaxhighlight lang="text">Printer does not print? y
A red light is flashing? n
Printer is unrecognised? y
Solutions:
Check the power cable
Check the printer-computer cable
Ensure printer software is installed</syntaxhighlight>
=={{header|C++}}==
{{trans|Java}}
<syntaxhighlight lang="cpp">#include <iostream>
#include <string>
#include <vector>
const std::vector<std::pair<std::string, std::string>> conditions = {
{"Printer prints", "NNNNYYYY"},
{"A red light is flashing", "YYNNYYNN"},
{"Printer is recognized by computer", "NYNYNYNY"}
};
const std::vector<std::pair<std::string, std::string>> actions = {
{"Check the power cable", "NNYNNNNN"},
{"Check the printer-computer cable", "YNYNNNNN"},
{"Ensure printer software is installed", "YNYNYNYN"},
{"Check/replace ink", "YYNNNYNN"},
{"Check for paper jam", "NYNYNNNN"},
};
int main() {
const size_t nc = conditions.size();
const size_t na = actions.size();
const size_t nr = conditions[0].second.size();
const int np = 7;
auto answers = new bool[nc];
std::string input;
std::cout << "Please answer the following questions with a y or n:\n";
for (size_t c = 0; c < nc; c++) {
char ans;
do {
std::cout << conditions[c].first << "? ";
std::getline(std::cin, input);
ans = std::toupper(input[0]);
} while (ans != 'Y' && ans != 'N');
answers[c] = ans == 'Y';
}
std::cout << "Recommended action(s)\n";
for (size_t r = 0; r < nr; r++) {
for (size_t c = 0; c < nc; c++) {
char yn = answers[c] ? 'Y' : 'N';
if (conditions[c].second[r] != yn) {
goto outer;
}
}
if (r == np) {
std::cout << " None (no problem detected)\n";
} else {
for (auto action : actions) {
if (action.second[r] == 'Y') {
std::cout << " " << action.first << '\n';
}
}
}
break;
outer: {}
}
delete[] answers;
return 0;
}</syntaxhighlight>
{{out}}
<pre>Please answer the following questions with a y or n:
Printer prints? n
A red light is flashing? n
Printer is recognized by computer? n
Recommended action(s)
Check the power cable
Check the printer-computer cable
Ensure printer software is installed</pre>
=={{header|COBOL}}==
<syntaxhighlight lang="cobol"> >> SOURCE FORMAT FREE
identification division.
program-id. 'decisiontable'.
environment division.
configuration section.
repository.
function all intrinsic.
data division.
working-storage section.
01 conditions.
03 notprinting pic x.
03 flashing pic x.
03 notrecognized pic x.
procedure division.
start-decision-table.
display space
display 'The printer does not print (Y or N) ' with no advancing
accept notprinting
display 'A red light is flashing (Y or N) ' with no advancing
accept flashing
display 'The printer is unrecognized (Y or N) ' with no advancing
accept notrecognized
move upper-case(conditions) to conditions
display space
*>decision table Printer troubleshooter
*> conditions
*>Printer does not print Y Y Y Y N N N N
*>A red light is flashing Y Y N N Y Y N N
*>Printer is unrecognized Y N Y N Y N Y N
*> actions
*>Check the power cable X
*>Check the printer-computer cable X X
*>Ensure printer software is installed X X X X
*>Check/replace ink X X X X
*>Check for paper jam X X
*>end decision table
evaluate notprinting also flashing also notrecognized
when 'Y' also 'Y' also 'Y'
display 'Check the printer-computer cable'
display 'Ensure printer software is installed'
display 'Check/replace ink'
when 'Y' also 'Y' also 'N'
display 'Check/replace ink'
display 'Check for paper jam'
when 'Y' also 'N' also 'Y'
display 'Check the power cable'
display 'Check the printer-computer cable'
display 'Ensure printer software is installed'
when 'Y' also 'N' also 'N'
display 'Check for paper jam'
when 'N' also 'Y' also 'Y'
display 'Ensure printer software is installed'
display 'Check/replace ink'
when 'N' also 'Y' also 'N'
display 'Check/replace ink'
when 'N' also 'N' also 'Y'
display 'Ensure printer software is installed'
when 'N' also 'N' also 'N'
display 'no action found'
when other
display 'invalid input: ' notprinting space flashing space notrecognized
end-evaluate
display space
stop run
.
end program 'decisiontable'.
</syntaxhighlight>
{{out}}
<pre>$ cobc -xj decisiontable.cob
The printer does not print (Y or N) n
A red light is flashing (Y or N) n
The printer is unrecognized (Y or N) y
Ensure printer software is installed
</pre>
=={{header|D}}==
<syntaxhighlight lang="d">import std.stdio, std.algorithm, std.exception, std.array;
immutable struct DecisionTable {
alias immutable(bool)[] IBA;
const string[] conds, actions;
immutable IBA[IBA] rules;
private static immutable(bool[]) growTo(in bool[] b,
in size_t newLen)
pure nothrow {
auto result = new bool[newLen];
result[0 .. b.length] = b[];
return result.assumeUnique;
}
this(immutable string[] c,
immutable string[] a,
immutable bool[][][] q) pure nothrow {
conds = c;
actions = a;
IBA[IBA] r;
foreach (p; q)
r[growTo(p[0], conds.length)] =
growTo(p[1], actions.length);
rules = r.assumeUnique;
}
string[] test(in bool[] tested,
in string NoMatchMsg="It is fine :)")
const pure nothrow {
string[] rightActions;
auto iTested = growTo(tested, conds.length);
if (iTested in rules)
foreach (immutable i, immutable e; rules[iTested])
if (e)
rightActions ~= actions[i];
if (!rightActions.empty)
return rightActions;
return [NoMatchMsg];
}
void consult() const {
bool[] query;
foreach (cond; conds) {
write(cond, "? [y=yes/others=no] ");
string answer = "no";
try
answer = stdin.readln;
catch (StdioException)
writeln("no");
query ~= !!answer.startsWith('y', 'Y');
}
writefln("%-(%2s\n%)", test(query));
}
}
void main() {
enum { F = false, T = true }
immutable d = immutable(DecisionTable)(
["Printer is unrecognised",
"A red light is flashing",
"Printer does not print"],
["Check the power cable",
"Check the printer-computer cable",
"Ensure printer software is installed",
"Check/replace ink",
"Check for paper jam"],
[[[T, F, F], [F, F, T]],
[[F, T, F], [F, F, F, T]],
[[T, T, F], [F, F, T, T]],
[[F, F, T], [F, F, F, F, T]],
[[T, F, T], [T, T, T]],
[[F, T, T], [F, F, F, T, T]],
[[T, T, T], [F, T, T, T, F]]
]
);
d.consult;
}</syntaxhighlight>
{{out}}
<pre>Printer is unrecognised? [y=yes/others=no] no
A red light is flashing? [y=yes/others=no] no
Printer does not print? [y=yes/others=no] no
It is fine :)</pre>
===Alternative Version===
{{trans|C}}
<syntaxhighlight lang="d">import std.stdio, std.string;
struct DataPair(size_t N) {
string message;
immutable char[N] truth;
}
immutable DataPair!8[] conditions = [
{"Printer does not print", "####...."},
{"A red light is flashing", "##..##.."},
{"Printer is unrecognised", "#.#.#.#."}];
immutable DataPair!8[] solutions = [
{"Check the power cable", "..#....."},
{"Check the printer-computer cable", "#.#....."},
{"Ensure printer software is installed", "#.#.#.#."},
{"Check/replace ink", "##..##.."},
{"Check for paper jam", ".#.#...."}];
void main() {
size_t code = 0;
foreach (immutable cond; conditions) {
write(cond.message, "? [y=yes/others=no] ");
string answer = "no";
try
answer = stdin.readln();
catch (StdioException)
writeln("no");
code = (code << 1) | !answer.startsWith('y', 'Y');
}
if (code == (2 ^^ conditions.length) - 1)
writeln("\nSo, you don't have a problem then?");
else {
writeln("\nSolutions:");
foreach (immutable sol; solutions)
if (sol.truth[code] == '#')
writeln(" ", sol.message);
}
}</syntaxhighlight>
{{out}}
<pre>Printer does not print? [y=yes/others=no] no
A red light is flashing? [y=yes/others=no] no
Printer is unrecognised? [y=yes/others=no] no
So, you don't have a problem then?</pre>
Keyboard handling is sketchy, just type "true" or "false" to each question.
=={{header|FreeBASIC}}==
<syntaxhighlight lang="freebasic">dim as boolean rules(0 to 2, 0 to 7) =_
{ {false, false, false, false, true, true, true, true},_
{ true, true, false, false, true, true, false, false},_
{false, true, false, true, false, true, false, true} }
dim as boolean actions(0 to 4, 0 to 7) =_
{ {false, false, true, false, false, false, false, false},_
{ true, false, true, false, false, false, false, false},_
{ true, false, true, false, true, false, true, false},_
{ true, true, false, false, false, true, false, false},_
{false, true, false, true, false, false, false, false} }
dim as string rule_names(0 to 2) =_
{"Printer prints", "A red light is flashing",_
"Printer is recognized by computer"}
dim as string action_names(0 to 4) = _
{"Check the power cable", "Check the printer-computer cable",_
"Ensure printer software is installed", "Check/replace ink",_
"Check for paper jam" }
dim as boolean answers(0 to 2)
for i as uinteger = 0 to 2
print rule_names(i),
input answers(i)
next i
print "---- Suggested solutions: ----"
for i as uinteger = 0 to 4
for j as uinteger = 0 to 7
if not actions(i, j) then continue for
for k as uinteger = 0 to 2
if rules(k, j)<>answers(j) then goto dontdoit
next k
print action_names(i)
dontdoit:
next j
next i</syntaxhighlight>
=={{header|Go}}==
Go has no specific support for decision tables, but they can be implemented easily. With a little ingenuity, literal data can be arranged in rows and columns in a way that preserves the visual associations of decision tables. Go has an init function that might be useful for compiling decision tables at program startup. And Go maps allow efficient lookup of actions given conditions.
<syntaxhighlight lang="go">package main
import (
"errors"
"fmt"
"os"
)
type dtText struct {
rules, text string
}
var ptText = []dtText{
{"YYYYNNNN", "Printer does not print"},
{"YYNNYYNN", "A red light is flashing"},
{"YNYNYNYN", "Printer is unrecognised"},
{"--------", ""},
{" X ", "Check the power cable"},
{"X X ", "Check the printer-computer cable"},
{"X X X X ", "Ensure printer software is installed"},
{"XX XX ", "Check/replace ink"},
{" X X ", "Check for paper jam"},
}
type dtMap map[string][]string
func compileDT(t []dtText) (dtMap, error) {
if len(t) == 0 {
return nil, errors.New("Empty decision table")
}
var conditions, actions []dtText
ruleColumns := len(t[0].rules)
for i, row := range t {
if len(row.rules) != ruleColumns {
return nil, errors.New("Inconsistent number of rule columns")
}
if len(row.text) == 0 {
if conditions != nil {
return nil, errors.New("Multple separator lines")
}
if i == 0 {
return nil, errors.New("No conditions specified")
}
if i == len(t)-1 {
return nil, errors.New("No actions specified")
}
conditions = t[:i]
actions = t[i+1:]
}
}
if conditions == nil {
return nil, errors.New("Missing separator line")
}
m := make(map[string][]string, ruleColumns)
kb := make([]byte, len(conditions))
for col := 0; col < ruleColumns; col++ {
for i, c := range conditions {
kb[i] = c.rules[col]
}
key := string(kb)
for _, a := range actions {
if a.rules[col] != ' ' {
m[key] = append(m[key], a.text)
}
}
}
return m, nil
}
func init() {
var err error
if ptMap, err = compileDT(ptText); err != nil {
fmt.Println(err)
os.Exit(1)
}
}
var ptMap dtMap
func main() {
for _, a := range ptMap["NYY"] {
fmt.Println(a)
}
}</syntaxhighlight>
Output:
<pre>
Ensure printer software is installed
Check/replace ink
</pre>
=={{header|Icon}} and {{header|Unicon}}==
<syntaxhighlight lang="icon">record cond(text,flags)
record act(text,flags,aflags)
procedure main()
DT := [
cond("Printer does not print", "YYYYNNNN"),
cond("A red light is flashing", "YYNNYYNN"),
cond("Printer is unrecognised", "YNYNYNYN"),
, # separator
act("Check the power cable", "NNYNNNNN"),
act("Check the printer-computer cable", "YNYNNNNN"),
act("Ensure printer software is installed", "YNYNYNYN"),
act("Check/replace ink", "YYNNYYNN"),
act("Check for paper jam", "NYNYNNNN") ]
every (act := [])[1 to *DT] := '' # empty csets for actions
ans := '' # empty answer cset
every d := DT[i := 1 to *DT] do {
/conds := list(*d.flags,'')
case type(d) of {
"cond":{
sel := cset(&cset[i]) # selector for this cond
ans ++:= ( ask(d.text) == "Y", sel) # ... add to answer
every j := 1 to *conds do # assemble condition flags
if d.flags[j] == "Y" then conds[j] ++:= sel
}
"act":{
d.aflags := list(*conds,'')
every j := 1 to *conds do {
if d.flags[j] == "Y" then
d.aflags[j] := conds[j] # matching conditions
if d.aflags[j] == ans
then write(d.text) # matched, write action
}
}
default: write("----------------------------") # separator
}
}
end
procedure ask(text)
repeat {
writes(text," ? ")
a := map(trim(read()),&lcase,&ucase)
case a of {
"Y": return a
"N": fail
default: write(a," is an invalid response, enter a Y or N, ")
}
}
end</syntaxhighlight>
Sample Output:<pre>Printer does not print ? Y
A red light is flashing ? N
Printer is unrecognised ? N
----------------------------
Check for paper jam</pre>
=={{header|J}}==
'''Solution''':<
'RULE_NAMES RULES'=: |:':'&cut;._2 noun define
Printer does not print: Y Y Y Y N N N N
A red light is flashing: Y Y N N Y Y N N
Line 10 ⟶ 978:
)
'ACTION_NAMES ACTIONS'=: |:':'&cut;._2 noun define
Check the power cable: - - X - - - - -
Check the printer-computer cable: X - X - - - - -
Line 18 ⟶ 986:
)
assert (-:~.)|: 'Y' =/&;:
RULE_TABLE=: (,/'X'=/&;: ACTIONS) /:&|: 'Y' =/&;:
troubleshoot =: verb define
Line 26 ⟶ 994:
'q a'=.x
smoutput 'Having trouble? Let''s track down the problem:'
options=. a #~ y {~ #. 'Y'={.@toupper@deb@(1!:1)@1:@smoutput@,&'?'
(,~ ('/'cut'Suggested resolutions:/Solution unknown.') {::~ 0=#) options
)</
'''Example''' (''solution found''):<
Having trouble? Let's track down the problem:
Printer does not print?
Line 41 ⟶ 1,009:
Check the printer-computer cable
Ensure printer software is installed
Check/replace ink </
'''Example''' (''solution not found''):<
Having trouble? Let's track down the problem:
Printer does not print?
Line 51 ⟶ 1,019:
N
Solution unknown.
</syntaxhighlight>
=== Comments ===
Line 58 ⟶ 1,026:
For large numbers of rules and few actions, J's native support of sparse arrays might provide a performance advantage, particularly in space. A minor note about the implementation here: the verb (function) <tt>troubleshoot</tt> is generalized, and reusable on any set of rule table, questions, and suggested actions. The default is to use those given in the printer troubleshooting table.
=={{header|
{{trans|Kotlin}}
<syntaxhighlight lang="java">import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.List;
import java.util.Objects;
public class DecisionTables {
private static class Pair<T, U> {
private final T t;
private final U u;
public static <T, U> Pair<T, U> of(T t, U u) {
public T getFirst() {
return t;
}
public U getSecond() {
return u;
}
}
private static final List<Pair<String, String>> conditions = List.of(
Pair.of("Printer prints", "NNNNYYYY"),
Pair.of("A red light is flashing", "YYNNYYNN"),
Pair.of("Printer is recognized by computer", "NYNYNYNY")
);
private static final List<Pair<String, String>> actions = List.of(
Pair.of("Check the power cable", "NNYNNNNN"),
Pair.of("Check the printer-computer cable", "YNYNNNNN"),
Pair.of("Ensure printer software is installed", "YNYNYNYN"),
Pair.of("Check/replace ink", "YYNNNYNN"),
Pair.of("Check for paper jam", "NYNYNNNN")
);
public static void main(String[] args) throws IOException {
final int nc = conditions.size();
final int na = actions.size();
final int nr = conditions.get(0).getSecond().length();
final int np = 7;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Please answer the following questions with a y or n:");
final boolean[] answers = new boolean[nc];
for (int c = 0; c < nc; ++c) {
String input;
do {
System.out.printf(" %s ? ", conditions.get(c).getFirst());
input = br.readLine().toUpperCase();
} while (!Objects.equals(input, "Y") && !Objects.equals(input, "N"));
answers[c] = Objects.equals(input, "Y");
}
System.out.println("\nRecommended action(s)");
outer:
for (int r = 0; r < nr; ++r) {
for (int c = 0; c < nc; ++c) {
char yn = answers[c] ? 'Y' : 'N';
if (conditions.get(c).getSecond().charAt(r) != yn) {
continue outer;
}
}
if (r == np) {
System.out.println(" None (no problem detected)");
} else {
for (Pair<String, String> action : actions) {
if (action.getSecond().charAt(r) == 'Y') {
System.out.printf(" %s\n", action.getFirst());
}
}
}
break;
}
}
}</syntaxhighlight>
{{out}}
<pre>Please answer the following questions with a y or n:
Printer prints ? n
A red light is flashing ? n
Printer is recognized by computer ? n
Recommended action(s)
Check the power cable
Check the printer-computer cable
Ensure printer software is installed</pre>
=={{header|JavaScript}}==
===Interactive===
Since this is an interactive web page, results can't be listed. See http://jsfiddle.net/rGP6C/1/ for a live demo.
<syntaxhighlight lang="javascript"><html>
<head></head>
<body>
<form id="form"></form>
<br/>Possible solutions:
<ul id="ul"></ul>
</body>
<script src="http://code.jquery.com/jquery-latest.min.js"></script>
<script type="text/javascript">
var questions = [
{ bools:[1,1,1,1,0,0,0,0], text:"Printer does not print" },
{ bools:[1,1,0,0,1,1,0,0], text:"A red light is flashing" },
{ bools:[1,0,1,0,1,0,1,0], text:"Printer is unrecognized" },
];
var answers = [
{ bools:[0,0,1,0,0,0,0,0], text:"Check the power cable" },
{ bools:[1,0,1,0,0,0,0,0], text:"Check the printer-computer cable" },
{ bools:[1,0,1,0,1,0,1,0], text:"Ensure printer software is installed" },
{ bools:[1,1,0,0,1,1,0,0], text:"Check/replace ink" },
{ bools:[0,1,0,1,0,0,0,0], text:"Check for paper jam" },
]
$(document).ready(function() {
// Init form with questions. "Value" is a descending power of 2.
var value = questions[0].bools.length;
for (var i = 0; i < questions.length; i++) {
value /= 2;
var el = '<br /><input type="checkbox" value="' + value + '">' + questions[i].text;
$("#form").append(el);
}
// Respond to a checkbox action.
$('input:checkbox').change(function() {
// Figure out which combination of checkboxes the user selected.
var sum = 0;
$('input:checkbox:checked').each(function () {
sum += Number(this.value);
});
// Translate sum into an index (column #) into bools.
var index = questions[0].bools.length - sum - 1;
// Clear the answers.
$('#ul').html('');
// Add appropriate answers.
for (var i = 0; i < answers.length; i++) {
if (answers[i].bools[index]) {
$('#ul').append('<li>' + answers[i].text + '</li>')
}
}
});
});
</script>
</html></syntaxhighlight>
===DecTab object===
This implements a DecisionTable object called <code>DecTab</code>. The JavaScript dialect is Microsoft's JScript.
<syntaxhighlight lang="javascript">
var DecTab = function () {
this.conditions = [];
this.rules = [];
this.actions = [];
}
DecTab.prototype.Conditions = function () {
var args = [].slice.call(arguments);
for (var i = 0; i < args.length; i++) {
this.conditions.push(args[i]);
}
return this;
};
DecTab.prototype.RulesActions = function (rules, actions) {
var count = 0;
var actionable;
this.rules.push(rules)
this.actions.push(actions);
return this;
};
DecTab.prototype.Decide = function () {
var decision = [];
var decided = false;
for (var i = 0; i < this.conditions.length; i++) {
decision.push((this.conditions[i]()));
}
var decisionstring = "." + decision.join(".") + ".";
for (i = 0; i < this.rules.length; i++) {
var rule = [];
for (var j = 0; j < this.rules[i].length; j++) {
rule.push((this.rules[i][j]));
}
var rulestring = "." + rule.join(".") + ".";
if (rulestring === decisionstring) {
decided = true;
for (var k = 0; k < this.actions[i].length; k++) {
this.actions[i][k]();
}
break;
}
}
if (!decided) {
WScript.Echo("No decision table rows matched.");
}
}
</syntaxhighlight>
The task is rendered as follows
<syntaxhighlight lang="javascript">
function Ask(q) {
WScript.StdOut.Write(q);
WScript.StdOut.Write(" [Y/N]?");
var ans = WScript.StdIn.ReadLine();
ans = ans.substr(0, 1).toUpperCase() === "Y" ? "Y" : "N";
return ans;
}
function Tell(w) {
WScript.Echo(w);
}
function Check_the_power_cable() {
Tell("Check the power cable.");
}
function Check_the_printer_computer_cable() {
Tell("Check the printer-computer cable.");
}
function Ensure_printer_software_is_installed() {
Tell("Ensure printer software is installed.");
}
function Check_replace_ink() {
Tell("Check/replace ink.");
}
function Check_for_paper_jam() {
Tell("Check for paper jam.");
}
function Printer_Prints() {
return Ask("Printer prints");
}
function A_red_light_is_flashing() {
return Ask("A red light is flashing");
}
function Printer_is_recognized_by_computer() {
return Ask("Printer is recognized by computer");
}
var DT = new DecTab()
.Conditions(
Printer_Prints,
A_red_light_is_flashing,
Printer_is_recognized_by_computer)
.RulesActions(["N", "Y", "N"], [Check_the_printer_computer_cable, Ensure_printer_software_is_installed, Check_replace_ink])
.RulesActions(["N", "Y", "Y"], [Check_replace_ink, Check_for_paper_jam])
.RulesActions(["N", "N", "N"], [Check_the_power_cable, Check_the_printer_computer_cable, Ensure_printer_software_is_installed])
.RulesActions(["N", "N", "Y"], [Check_for_paper_jam])
.RulesActions(["Y", "Y", "N"], [Ensure_printer_software_is_installed, Check_replace_ink])
.RulesActions(["Y", "Y", "Y"], [Check_replace_ink])
.RulesActions(["Y", "N", "N"], [Ensure_printer_software_is_installed])
.RulesActions(["Y", "N", "Y"], [])
.Decide();
</syntaxhighlight>
And a sample run
<syntaxhighlight lang="text">
C:\>CScript DecisionTable.js
Printer prints [Y/N]?Y
A red light is flashing [Y/N]?Y
Printer is recognized by computer [Y/N]?Y
Check/replace ink.
</syntaxhighlight>
=={{header|jq}}==
{{trans|Wren}}
{{works with|jq}}
'''Works with gojq, the Go implementation of jq'''
In the following solution, `input` is used to read the user's
yes/no responses, and so jq should be invoked with the -R and -n command-line options.
Because of the limitations of jq's I/O capabilities, the
prompts for this task are written to stderr, which unfortunately makes them
untidy.
<syntaxhighlight lang="jq">def get_response:
input
| if . == "Y" or . == "y" then "Y"
elif . == "N" or . == "n" then "N"
else null
end;
def ask($prompt):
def ask:
$prompt|stderr
| get_response
| if . then . else ask end;
ask;
def conditions: [
["Printer prints" , "NNNNYYYY"],
["A red light is flashing" , "YYNNYYNN"],
["Printer is recognized by computer", "NYNYNYNY"]
];
def actions: [
["Check the power cable" , "NNYNNNNN"],
["Check the printer-computer cable" , "YNYNNNNN"],
["Ensure printer software is installed", "YNYNYNYN"],
["Check/replace ink" , "YYNNNYNN"],
["Check for paper jam" , "NYNYNNNN"]
];
def interact:
conditions as $conditions
| actions as $actions
| ($conditions|length) as $nc
| ($actions|length) as $na
| ($conditions[0][1]|length) as $nr # number of rules
| 7 as $np # index of 'no problem' rule
| "Please answer the following questions with a y or n:",
( reduce range(0; $nc) as $c ( null;
.[$c] = ask("\($conditions[$c][0])? ") )) as $answers
| ("\nRecommended action(s):",
label $out
| range(0; $nr) as $r
| if all( range(0; $nc); $conditions[.][1][$r:$r+1] == $answers[.])
then if $r == $np
then "None (no problem detected)."
else $actions[] | select(.[1][$r:$r+1] == "Y") | .[0]
end,
break $out
else empty
end ) ;
interact
</syntaxhighlight>
'''Example (transcript)'''
<pre>
$ jq -rRn -f decision-tables.jq
Please answer the following questions with a y or n:
"Printer prints? "n
"A red light is flashing? "n
"Printer is recognized by computer? "n
Recommended action(s):
Check the power cable
Check the printer-computer cable
Ensure printer software is installed
</pre>
=={{header|Julia}}==
{{trans|Perl}}
<syntaxhighlight lang="julia">const queries = [("Printer does not print", 0b11110000),
("A red light is flashing", 0b11001100),
("Printer is unrecognised", 0b10101010)]
const answers = Dict(0b00100000 => "Check the power cable",
0b10100000 => "Check the printer-computer cable",
0b10101010 => "Ensure printer software is installed",
0b11001100 => "Check/replace ink",
0b01010000 => "Check for paper jam",
0b00000001 => "Cannot diagnose any problem.")
function ynprompt(prompt)
while true
print(prompt, "?: ")
if (ans = strip(uppercase(readline()))[1]) in ['Y', 'N']
return ans
end
end
end
function decide(queries, answers)
cond = 0b11111111
for (prompt, value) in queries
cond &= (ynprompt(prompt) == 'Y' ? value : UInt8(~value))
end
for (bitpat, diagnosis) in answers
if cond & bitpat != 0
println(diagnosis)
end
end
end
decide(queries, answers)
</syntaxhighlight>{{out}}
<pre>
Printer does not print?: y
A red light is flashing?: y
Printer is unrecognised?: n
Check/replace ink
Check for paper jam
</pre>
=={{header|Kotlin}}==
<syntaxhighlight lang="scala">// version 1.1.51
val conditions = listOf(
"Printer prints" to "NNNNYYYY",
"A red light is flashing" to "YYNNYYNN",
"Printer is recognized by computer" to "NYNYNYNY"
)
val actions = listOf(
"Check the power cable" to "NNYNNNNN",
"Check the printer-computer cable" to "YNYNNNNN",
"Ensure printer software is installed" to "YNYNYNYN",
"Check/replace ink" to "YYNNNYNN",
"Check for paper jam" to "NYNYNNNN"
)
fun main(args: Array<String>) {
val nc =
val na =
val nr = conditions[0].second.length // number of rules
val np = 7 // index of
println("Please answer the following questions with a y or n:")
val answers = BooleanArray(nc)
for (c in 0 until nc) {
var input: String
do {
print(" ${conditions[c].first} ? ")
input = readLine()!!.toUpperCase()
}
while (input != "Y" && input != "N")
answers[c] = (input == "Y")
}
println("\nRecommended action(s):")
outer@ for (r in 0 until nr) {
for (c in 0 until nc) {
val yn = if (answers[c]) 'Y' else 'N'
if (conditions[c].second[r] != yn) continue@outer
}
if (r == np) {
println(" None (no problem detected)")
}
else {
for (a in 0 until na) {
if (actions[a].second[r] == 'Y') println(" ${actions[a].first}")
}
}
return
}
}</syntaxhighlight>
Sample input/output:
<pre>
Please answer the following questions with a y or n:
Printer prints ? n
A red light is flashing ? n
Printer is recognized by computer ? n
Recommended action(s):
Check the power cable
Check the printer-computer cable
Ensure printer software is installed
</pre>
=={{header|Lua}}==
{{trans|C++}}
<syntaxhighlight lang="lua">function promptYN(q)
local ans = '?'
repeat
io.write(q..'? ')
ans = string.upper(io.read())
until ans == 'Y' or ans == 'N'
return ans == 'Y'
end
function getCharAt(s,i)
return string.sub(s,i,i)
end
conditions = {
{"Printer prints", "NNNNYYYY"},
{"A red light is flashing", "YYNNYYNN"},
{"Printer is recognized by computer", "NYNYNYNY"},
}
actions = {
{"Check the power cable", "NNYNNNNN"},
{"Check the printer-computer cable", "YNYNNNNN"},
{"Ensure printer software is installed", "YNYNYNYN"},
{"Check/replace ink", "YYNNNYNN"},
{"Check for paper jam", "NYNYNNNN"},
}
nc = #conditions
nr = string.len(conditions[1][2])
answers = {}
print('Please answer the following questions with a y or n:')
for i,v in pairs(conditions) do
answers[i] =
end
print('Recommended action(s)')
for r=1,nr do
local skip = false
for c=1,nc do
local yn = answers[c] and 'Y' or 'N'
if getCharAt(conditions[c][2], r) ~= yn then
skip = true
break
end
end
if not skip then
if r == nr then
print(" None (no problem detected)")
else
for i,a in pairs(actions) do
if getCharAt(a[2], r) == 'Y' then
print(" ", a[1])
end
end
end
end
end</syntaxhighlight>
{{out}}
<pre>Please answer the following questions with a y or n:
Printer prints? n
A red light is flashing? n
Printer is recognized by computer? n
Recommended action(s)
Check the power cable
Check the printer-computer cable
Ensure printer software is installed</pre>
=={{header|Nim}}==
We have defined a generic decision table object and used it with the Wikipedia printer example.
<syntaxhighlight lang="nim">import strutils, tables
####################################################################################################
# Generic defintion of the decision table.
type
DTable[Cond, Act: Ordinal] = object
questions: array[Cond, string]
answers: array[Act, string]
rules: Table[set[Cond], seq[Act]]
proc initDTable[Cond, Act](): DTable[Cond, Act] = discard
proc addCondition[Cond, Act](dt: var DTable[Cond, Act]; cond: Cond; question: string) =
if dt.questions[cond].len != 0:
raise newException(ValueError, "condition already set: " & $cond)
dt.questions[cond] = question
proc addAction[Cond, Act](dt: var DTable[Cond, Act]; act: Act; answer: string) =
if dt.answers[act].len != 0:
raise newException(ValueError, "action already set: " & $act)
dt.answers[act] = answer
proc addRule[Cond, Act](dt: var DTable[Cond, Act]; rule: set[Cond]; acts: openArray[Act]) =
if rule in dt.rules:
raise newException(ValueError, "rule already set.")
dt.rules[rule] = @acts
proc askQuestion(question: string): string =
while true:
stdout.write question & ' '
stdout.flushFile()
result = stdin.readLine().strip()
if result in ["y", "n"]: break
proc apply[Cond, Act](dt: DTable[Cond, Act]) =
# Build condition set.
var conds: set[Cond]
echo "Answer questions with 'y' or 'n'"
for cond, question in dt.questions:
if question.len == 0:
raise newException(ValueError, "missing question for condition: " & $cond)
let answer = askQuestion(question)
if answer == "y":
conds.incl cond
# Apply rule.
echo()
if conds in dt.rules:
echo "Actions recommended:"
for act in dt.rules[conds]:
echo "- ", dt.answers[act]
else:
echo "No action recommended."
####################################################################################################
# Decision table for Wikipedia printer example.
type
Condition {.pure.} = enum PrinterPrints, RedLightFlashing, PrinterRecognized
Action {.pure.} = enum CheckPowerCable, CheckPrinterCable, CheckSoftware, CheckInk, CheckPaperJam
const
Questions = [PrinterPrints: "Does printer print?",
RedLightFlashing: "Does red light is flashing?",
PrinterRecognized: "Is printer recognized by computer?"]
Answers = [CheckPowerCable: "check the power cable",
CheckPrinterCable: "check the printer-computer cable",
CheckSoftware: "ensure printer software is installed",
CheckInk: "check/replace ink",
CheckPaperJam: "check for paper jam"]
var dt = initDTable[Condition, Action]()
for cond, question in Questions:
dt.addCondition(cond, question)
for act, answer in Answers:
dt.addAction(act, answer)
dt.addRule({}, [CheckPowerCable, CheckPrinterCable, CheckSoftware])
dt.addRule({PrinterPrints}, [CheckSoftware])
dt.addRule({RedLightFlashing}, [CheckPrinterCable, CheckSoftware, CheckInk])
dt.addRule({PrinterRecognized}, [CheckPaperJam])
dt.addRule({PrinterPrints, RedLightFlashing}, [CheckSoftware])
dt.addRule({RedLightFlashing, PrinterRecognized}, [CheckInk, CheckPaperJam])
dt.addRule({PrinterPrints, RedLightFlashing, PrinterRecognized}, [CheckInk])
dt.apply()</syntaxhighlight>
{{out}}
<pre>Answer questions with 'y' or 'n'
Does printer print? n
Does red light is flashing? y
Is printer recognized by computer? y
Actions recommended:
- check/replace ink
- check for paper jam</pre>
=={{header|Perl}}==
<syntaxhighlight lang="perl" line>use v5.36;
sub decide($q,$a) {
my @q = @{$q};
my %a = %{$a};
my($cnt,$bit) = (1,0);
for my $prompt (@q) {
print "$prompt: ";
$bit += $cnt if <> =~ /y/i;
$cnt *= 2;
}
$bit = 2**$bit;
while (my ($bitpat,$diagnosis) = each %a) {
print "$diagnosis\n" if $bit & $bitpat;
}
}
my @queries = (
'Printer is unrecognised',
'A red light is flashing',
'Printer does not print',
);
my %answers = (
0b00100000 => 'Check the power cable',
0b10100000 => 'Check the printer-computer cable',
0b10101010 => 'Ensure printer software is installed',
0b11001100 => 'Check/replace ink',
0b01010000 => 'Check for paper jam',
);
decide(\@queries,\%answers);</syntaxhighlight>
{{out}}
<pre>Printer is unrecognised: n
A red light is flashing: n
Printer does not print: y
Check for paper jam</pre>
=={{header|Phix}}==
Written such that conditions and actions could easily be read from a plain text file,
and should cope fairly well with different lengths, missing/conflicting options, etc.
=== console version ===
<!--<syntaxhighlight lang="phix">-->
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (wait_key)</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">conditions</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"""
YYYYNNNN:Printer does not print
YYNNYYNN:A red light is flashing
YNYNYNYN:Printer is unrecognized
"""</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">actions</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"""
--X-----:Check the power cable
X-X-----:Check the printer-computer cable
X-X-X-X-:Ensure printer software is installed
XX--XX--:Check/replace ink
-X-X----:Check for paper jam
"""</span>
<span style="color: #008080;">procedure</span> <span style="color: #000000;">validate</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">l</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">string</span> <span style="color: #000000;">letters</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">name</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">),</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
<span style="color: #7060A8;">throw</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"uneven %s pairings"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">name</span><span style="color: #0000FF;">}))</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">by</span> <span style="color: #000000;">2</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">si</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">si</span><span style="color: #0000FF;">)!=</span><span style="color: #000000;">l</span> <span style="color: #008080;">then</span>
<span style="color: #7060A8;">throw</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"mismatched lengths (line %d)"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">i</span><span style="color: #0000FF;">))</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">si</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">si</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">],</span><span style="color: #000000;">letters</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
<span style="color: #7060A8;">throw</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"invalid letter [%c not in %s]"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">si</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">],</span><span style="color: #000000;">letters</span><span style="color: #0000FF;">}))</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">qa</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">split_any</span><span style="color: #0000FF;">(</span><span style="color: #000000;">conditions</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n:"</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">sa</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">split_any</span><span style="color: #0000FF;">(</span><span style="color: #000000;">actions</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n:"</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">l</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">qa</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">])</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">ask_questions</span><span style="color: #0000FF;">()</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">valid</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #004600;">true</span><span style="color: #0000FF;">,</span><span style="color: #000000;">l</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">a</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">qa</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">by</span> <span style="color: #000000;">2</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">while</span> <span style="color: #004600;">true</span> <span style="color: #008080;">do</span>
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">qa</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]&</span><span style="color: #008000;">":? "</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">a</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">upper</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">wait_key</span><span style="color: #0000FF;">())</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"YN"</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\nplease enter Y or N\n"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%c\n"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">a</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">l</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">a</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">qa</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">then</span> <span style="color: #000000;">valid</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #004600;">false</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">return</span> <span style="color: #000000;">valid</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">procedure</span> <span style="color: #000000;">show_answers</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">k</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">count</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sa</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">by</span> <span style="color: #000000;">2</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">sa</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]=</span><span style="color: #008000;">'X'</span> <span style="color: #008080;">then</span>
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">sa</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]&</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">count</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%d answers\n"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">count</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #008080;">procedure</span> <span style="color: #000000;">main</span><span style="color: #0000FF;">()</span>
<span style="color: #008080;">try</span>
<span style="color: #000000;">validate</span><span style="color: #0000FF;">(</span><span style="color: #000000;">qa</span><span style="color: #0000FF;">,</span><span style="color: #000000;">l</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"YN"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"condition"</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">validate</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sa</span><span style="color: #0000FF;">,</span><span style="color: #000000;">l</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"-X"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"action"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">catch</span> <span style="color: #000000;">e</span>
<span style="color: #0000FF;">?</span><span style="color: #000000;">e</span>
<span style="color: #7060A8;">abort</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">try</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">valid</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">ask_questions</span><span style="color: #0000FF;">()</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">sv</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sum</span><span style="color: #0000FF;">(</span><span style="color: #000000;">valid</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">sv</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"no answers"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">elsif</span> <span style="color: #000000;">sv</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">show_answers</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #004600;">true</span><span style="color: #0000FF;">,</span><span style="color: #000000;">valid</span><span style="color: #0000FF;">))</span>
<span style="color: #008080;">else</span>
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"multiple answer sets\n"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">valid</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">valid</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">then</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"for %d:\n"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">i</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">show_answers</span><span style="color: #0000FF;">(</span><span style="color: #000000;">i</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #000000;">main</span><span style="color: #0000FF;">()</span>
<!--</syntaxhighlight>-->
{{out}}
<pre>
Printer does not print:? N
A red light is flashing:? Y
Printer is unrecognized:? Y
Ensure printer software is installed
Check/replace ink
2 answers
</pre>
=== GUI version ===
{{libheader|Phix/pGUI}}
<!--<syntaxhighlight lang="phix">(phixonline)-->
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">conditions</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"""
YYYYNNNN:Printer does not print
YYNNYYNN:A red light is flashing
YNYNYNYN:Printer is unrecognized
"""</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">actions</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"""
--X-----:Check the power cable
X-X-----:Check the printer-computer cable
X-X-X-X-:Ensure printer software is installed
XX--XX--:Check/replace ink
-X-X----:Check for paper jam
"""</span>
<span style="color: #008080;">constant</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">qyn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">qus</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">columnize</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #004600;">true</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">split</span><span style="color: #0000FF;">,{</span><span style="color: #7060A8;">split</span><span style="color: #0000FF;">(</span><span style="color: #000000;">conditions</span><span style="color: #0000FF;">,</span><span style="color: #008000;">'\n'</span><span style="color: #0000FF;">),</span><span style="color: #008000;">':'</span><span style="color: #0000FF;">})),</span>
<span style="color: #0000FF;">{</span><span style="color: #000000;">a_x</span><span style="color: #0000FF;">,</span><span style="color: #000000;">act</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">columnize</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #004600;">true</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">split</span><span style="color: #0000FF;">,{</span><span style="color: #7060A8;">split</span><span style="color: #0000FF;">(</span><span style="color: #000000;">actions</span><span style="color: #0000FF;">,</span><span style="color: #008000;">'\n'</span><span style="color: #0000FF;">),</span><span style="color: #008000;">':'</span><span style="color: #0000FF;">}))</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">nq</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">qus</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">na</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">act</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">ynl</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">qyn</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">])</span>
<span style="color: #7060A8;">assert</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #000000;">qyn</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">)=</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">ynl</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nq</span><span style="color: #0000FF;">),</span><span style="color: #008000;">"mismatched YN lengths"</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">assert</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a_x</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">)=</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">ynl</span><span style="color: #0000FF;">,</span><span style="color: #000000;">na</span><span style="color: #0000FF;">),</span><span style="color: #008000;">"mismatched X- lengths"</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">assert</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">unique</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">qyn</span><span style="color: #0000FF;">,</span><span style="color: #008000;">""</span><span style="color: #0000FF;">))=</span><span style="color: #008000;">"NY"</span> <span style="color: #008080;">and</span> <span style="color: #7060A8;">unique</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a_x</span><span style="color: #0000FF;">,</span><span style="color: #008000;">""</span><span style="color: #0000FF;">))=</span><span style="color: #008000;">"-X"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">title</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"Decision_tables"</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">help_text</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"""
Check all that apply and press the "Get Answers" button.
"""</span>
<span style="color: #008080;">include</span> <span style="color: #000000;">pGUI</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
<span style="color: #004080;">Ihandle</span> <span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">tbox</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">hbox</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">vbox</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">okbtn</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">answers</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">toggles</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">show_help</span><span style="color: #0000FF;">()</span>
<span style="color: #7060A8;">IupMessage</span><span style="color: #0000FF;">(</span><span style="color: #000000;">title</span><span style="color: #0000FF;">,</span><span style="color: #000000;">help_text</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">return</span> <span style="color: #004600;">IUP_IGNORE</span> <span style="color: #000080;font-style:italic;">-- (don't open browser help!)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">button_cb</span><span style="color: #0000FF;">(</span><span style="color: #004080;">Ihandle</span> <span style="color: #000080;font-style:italic;">/*okbtn*/</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">valid</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #004600;">true</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ynl</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">nq</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">yn</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"YN"</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">-</span><span style="color: #7060A8;">IupGetInt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">toggles</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">],</span><span style="color: #008000;">"VALUE"</span><span style="color: #0000FF;">)]</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">ynl</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">yn</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">qyn</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">then</span> <span style="color: #000000;">valid</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #004600;">false</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">sv</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sum</span><span style="color: #0000FF;">(</span><span style="color: #000000;">valid</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">answer</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sv</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span><span style="color: #0000FF;">?</span><span style="color: #008000;">"no answers"</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sv</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span><span style="color: #0000FF;">?</span><span style="color: #008000;">""</span><span style="color: #0000FF;">:</span><span style="color: #008000;">"multiple answer sets\n"</span><span style="color: #0000FF;">))</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">sv</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">ynl</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">valid</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">then</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">sv</span><span style="color: #0000FF;">></span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">answer</span> <span style="color: #0000FF;">&=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"for %d:\n"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">i</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">actions</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">na</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">a_x</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]=</span><span style="color: #008000;">'X'</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">actions</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">actions</span><span style="color: #0000FF;">,</span><span style="color: #000000;">act</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">])</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #000000;">actions</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">actions</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"%d answers\n"</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">actions</span><span style="color: #0000FF;">)))</span>
<span style="color: #000000;">answer</span> <span style="color: #0000FF;">&=</span> <span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">actions</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #7060A8;">IupSetStrAttribute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">answers</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"TITLE"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">answer</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">IupSetAttribute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"SIZE"</span><span style="color: #0000FF;">,</span><span style="color: #004600;">NULL</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">IupRefresh</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">return</span> <span style="color: #004600;">IUP_DEFAULT</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">key_cb</span><span style="color: #0000FF;">(</span><span style="color: #004080;">Ihandle</span> <span style="color: #000080;font-style:italic;">/*dlg*/</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #004600;">K_ESC</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_CLOSE</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- (standard practice for me)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #004600;">K_F5</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_DEFAULT</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- (let browser reload work)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #004600;">K_F1</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #000000;">show_help</span><span style="color: #0000FF;">()</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #004600;">K_CR</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #000000;">button_cb</span><span style="color: #0000FF;">(</span><span style="color: #000000;">okbtn</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">return</span> <span style="color: #004600;">IUP_IGNORE</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #7060A8;">IupOpen</span><span style="color: #0000FF;">()</span>
<span style="color: #000000;">toggles</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #004600;">true</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">IupToggle</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">qus</span><span style="color: #0000FF;">,{</span><span style="color: #008000;">"RIGHTBUTTON=YES, CANFOCUS=NO"</span><span style="color: #0000FF;">}})</span>
<span style="color: #000000;">okbtn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupButton</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Get Answers"</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">Icallback</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"button_cb"</span><span style="color: #0000FF;">),</span><span style="color: #008000;">"PADDING=5x5"</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">answers</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupLabel</span><span style="color: #0000FF;">(</span><span style="color: #008000;">""</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"EXPAND=BOTH, PADDING=10x10"</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">tbox</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupVbox</span><span style="color: #0000FF;">(</span><span style="color: #000000;">toggles</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"ALIGNMENT=ARIGHT"</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">hbox</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupHbox</span><span style="color: #0000FF;">({</span><span style="color: #000000;">tbox</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">IupVbox</span><span style="color: #0000FF;">({</span><span style="color: #7060A8;">IupLabel</span><span style="color: #0000FF;">(),</span><span style="color: #000000;">okbtn</span><span style="color: #0000FF;">})})</span>
<span style="color: #000000;">vbox</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupVbox</span><span style="color: #0000FF;">({</span><span style="color: #000000;">hbox</span><span style="color: #0000FF;">,</span><span style="color: #000000;">answers</span><span style="color: #0000FF;">},</span><span style="color: #008000;">"MARGIN=20x10"</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">dlg</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupDialog</span><span style="color: #0000FF;">(</span><span style="color: #000000;">vbox</span><span style="color: #0000FF;">,</span><span style="color: #008000;">`TITLE="%s", MINSIZE=540x200`</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">title</span><span style="color: #0000FF;">})</span>
<span style="color: #7060A8;">IupShow</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">IupSetCallback</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"KEY_CB"</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">Icallback</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"key_cb"</span><span style="color: #0000FF;">))</span>
<span style="color: #7060A8;">IupSetAttributeHandle</span><span style="color: #0000FF;">(</span><span style="color: #004600;">NULL</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"PARENTDIALOG"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">platform</span><span style="color: #0000FF;">()!=</span><span style="color: #004600;">JS</span> <span style="color: #008080;">then</span>
<span style="color: #7060A8;">IupMainLoop</span><span style="color: #0000FF;">()</span>
<span style="color: #7060A8;">IupClose</span><span style="color: #0000FF;">()</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<!--</syntaxhighlight>-->
=={{header|Picat}}==
===Interactive version===
<syntaxhighlight lang="picat">import util.
%
% Interactive version.
% Answer with YnNn
%
go =>
conditions(Conditions),
solutions(Solutions),
Answers=query(Conditions),
println(join(decision_table(Solutions,Answers),'\n')),
nl.
%
% Query the user about the problem.
% Valid responses: YyNn
%
query(Conditions) = Answers =>
Answers = [0 : _I in 1..Conditions[1,2].length],
println("Please answer the questions with YyNn."),
foreach([Text,Cond] in Conditions)
A = "",
while (not(membchk(A, ["Y","N","y","n"])))
printf("%s? ", Text),
A := read_line(),
if membchk(A,["Y","y"]) then
Answers := map(\/, Answers,Cond)
end
end
end,
nl.
%
% Get the result given the answers (list of 01).
%
decision_table(Solutions,Answers) = Result =>
Result = [],
if sum(Answers) = 0 then
Result := ["Nice, no problem."]
else
foreach([Text,Sol] in Solutions)
if map(/\,Sol,Answers) == Sol then
Result := Result ++ [Text]
end
end
end.
conditions(Conditions) =>
Conditions = [
["Printer does not print", [1,1,1,1,0,0,0,0]],
["A red light is flashing", [1,1,0,0,1,1,0,0]],
["Printer is unrecognised", [1,0,1,0,1,0,1,0]]
].
solutions(Solutions) =>
Solutions = [
["Check the power cable", [0,0,1,0,0,0,0,0]],
["Check the printer-computer cable", [1,0,1,0,0,0,0,0]],
["Ensure printer software is installed",[1,0,1,0,1,0,1,0]],
["Check/replace ink", [1,1,0,0,1,1,0,0]],
["Check for paper jam", [0,1,0,1,0,0,0,0]]
].</syntaxhighlight>
{{out}}
<pre>
Please answer the questions with YyNn.
Printer does not print? y
A red light is flashing? n
Printer is unrecognised? y
Check the power cable
Check the printer-computer cable
Ensure printer software is installed
Check for paper jam</pre>
===All possible answers/combinations===
For debugging purposes it it's nice to be able to print all the possible combinations of answers/solutions.
<syntaxhighlight lang="picat">%
% Go through all combinations of answers
%
go2 =>
PS = power_set([1,2,3]).delete([]).sort(),
println(PS),
conditions(Conditions),
solutions(Solutions),
AllCond = [Cond : [_,Cond] in Conditions],
foreach(P in PS)
println(p=P),
println(conditions=join([Conditions[I].first() : I in P],', ')),
A = [0:_I in 1..Conditions[1,2].length],
foreach(C in [AllCond[I] : I in P])
A := map(\/,A,C)
end,
println(a=A),
println(join(decision_table(Solutions,A),'\n')),
nl
end,
nl.</syntaxhighlight>
{{out}}
(truncated)
<pre>
p = [1]
conditions = Printer does not print
a = [1,1,1,1,0,0,0,0]
Check the power cable
Check the printer-computer cable
Check for paper jam
p = [1,2]
conditions = Printer does not print, A red light is flashing
a = [1,1,1,1,1,1,0,0]
Check the power cable
Check the printer-computer cable
Check/replace ink
Check for paper jam
p = [1,2,3]
conditions = Printer does not print, A red light is flashing, Printer is unrecognised
a = [1,1,1,1,1,1,1,0]
Check the power cable
Check the printer-computer cable
Ensure printer software is installed
Check/replace ink
Check for paper jam
...
</pre>
=={{header|PicoLisp}}==
We allow ourselves a luxurious user interface:
<
(out NIL (prin (car Cond) "? "))
(in NIL
Line 147 ⟶ 2,048:
T )
(T (member Reply '(NIL N NO No n no false 0)))
(prinl "Please answer 'Yes' or 'No'") ) ) ) )</
The decision table used in the example:
<
("Printer does not print" T T T T NIL NIL NIL NIL)
("A red light is flashing" T T NIL NIL T T NIL NIL)
Line 159 ⟶ 2,060:
("Ensure printer software is installed" T NIL T NIL T NIL T)
("Check/replace ink" T T NIL NIL T T)
("Check for paper jam" NIL T NIL T) )</
The decision can be made directly on the condition and action data, without the need to create intermediate tables:
<
(let Reply (mapcar yes? *Conditions)
(extract and
Line 168 ⟶ 2,069:
(unless (pick '((Flg) (<> Flg (next))) Reply)
(rest) ) ) )
(mapcar car *Actions) ) ) )</
Output:
<pre>: (decide)
Line 189 ⟶ 2,090:
=={{header|Python}}==
<
'''
Create a Decision table then use it
Line 228 ⟶ 2,129:
dt_user(dt)
dt_user(dt)
dt_user(dt)</
'''Sample Run'''
Line 279 ⟶ 2,180:
Try this:
Pray!</pre>
=={{header|Quackery}}==
<syntaxhighlight lang="Quackery"> [ say "Check power cable." cr ] is cpc ( --> )
[ say "Check printer-computer cable." cr ] is cpcc ( --> )
[ say "Ensure printer software installed." cr ] is epsi ( --> )
[ say "Check/replace ink." cr ] is cri ( --> )
[ say "Check for paper jam." cr ] is cpj ( --> )
[ say "No problem detected." cr ] is npd ( --> )
[ [ dup $ " (y/n) " join input
dup $ "" = iff drop again ]
nip 0 peek upper char Y = ] is condition ( $ --> b )
[ $ "Does the printer print?"
condition
$ "Is a red light flashing?"
condition
$ "Does the computer recognise the printer?"
condition
1 << | 1 << |
[ table
( n n n ) [ cpc cpcc epsi ]
( y n n ) epsi
( n y n ) [ cpcc epsi cri ]
( y y n ) epsi
( n n y ) cpj
( y n y ) npd
( n y y ) [ cri cpj ]
( y y y ) cri ]
cr do ] is diagnose ( --> )</syntaxhighlight>
{{out}}
As a dialogue in the Quackery shell.
<pre>/O> diagnose
...
Does the printer print? (y/n) n
Is a red light flashing? (y/n) n
Does the computer recognise the printer? (y/n) y
Check for paper jam.
</pre>
=={{header|Racket}}==
This implementation shows off the 2d language. The "Actions" could be a square array of empty and X boxes.
I thought it might be fun to merge them.
<syntaxhighlight lang="racket">#lang unstable/2d racket
(define (ask-y/n q)
(printf "~a [y/n]?" q)
(define (get-y/n)
(match (read-line)
[(? eof-object?) eof]
[(regexp #rx"^[yY]") #t]
[(regexp #rx"^[nN]") #f]
[_ (printf "reply yes or no, please:") (get-y/n)]))
(get-y/n))
(define (cells->hash grid)
(for*/hash ((block (in-list grid)) (address (in-list (car block))))
(values address (match (cdr block)
['(N) #f]
['(Y) #t]
['(X) 'X]
[else else]))))
(define (run-decision-table tbl)
(match-define (list '2ddecision_table col-widths row-heights all-cells ...) tbl)
;; after this, the rules without an X are removed
(define full-cells (filter (match-lambda [(list _ _ _ ...) #t] [_ #f]) all-cells))
;; cell addresses are (list column row)
(match-define
(list-no-order
`((,_ ... (1 1) ,_ ...) ,caption ...)
`(((,rules-columns ,_) ...) Rules)
`(((,(app add1 text-columns) ,condition-rows) ...) Conditions)
`(((,_ ,action-rows) ...) Actions)
remaining-cells ...)
full-cells)
(define remaining-cells# (cells->hash remaining-cells))
(define (cell# c r (dflt #f))
(hash-ref remaining-cells# (list c r) dflt))
(define text-column (first text-columns))
(let question-loop ((remain-conds condition-rows) (remain-acts action-rows))
(match remain-conds
[(list) (displayln "I give up... read the manual or something.")]
[(list conds-h conds-t ...)
(match (ask-y/n (string-join (map ~a (cell# text-column conds-h)) " "))
[(? eof-object?) "bye!"]
[y/n-response
(define remain-acts-
(for/list
((action remain-acts)
#:when (for/first
((rule-c (in-list rules-columns))
#:when (eq? (cell# rule-c conds-h) y/n-response) ; matches rule flag
#:when (equal? (cell# rule-c action #f) 'X)) ; has an X
#t))
action))
(match remain-acts-
[(list) (printf "No more actions... no more suggestions from the rules!~%")]
[(list only-action) (printf "Suggested action: ~s~%" (cell# text-column only-action))]
[_ (question-loop conds-t remain-acts-)])])])))
(define printer-troubleshooting-2dtable
'#2ddecision_table
╔═╦════════════╦════════════════════════════════════════════╦═╦═╦═╦═╦═╦═╦═╦═╗
║ ║ ║ ║ ║ ║ ║ ║ ║ ║ ║ ║
╠═╬════════════╩════════════════════════════════════════════╬═╩═╩═╩═╩═╩═╩═╩═╣
║ ║ Printer troubleshooter ║ Rules ║
╠═╬════════════╦════════════════════════════════════════════╬═══════╦═══════╣
║ ║ Conditions ║ Printer does not print ║Y ║N ║
╠═╣ ╠════════════════════════════════════════════╣ ╔═══╬═══╗ ║
║ ║ ║ A red light is flashing ║ ║N ║Y ║ ║
╠═╣ ╠════════════════════════════════════════════╣ ╔═╬═╗ ║ ╔═╬═╗ ║
║ ║ ║ Printer is unrecognized ║ ║N║Y║ ║ ║N║Y║ ║
╠═╬════════════╬════════════════════════════════════════════╬═╩═╬═╬═╩═╩═╩═╩═╣
║ ║ Actions ║ Check the power cable ║ ║X║ ║
╠═╣ ╠════════════════════════════════════════════╬═╗ ║ ║ ║
║ ║ ║ Check the printer-computer cable ║X║ ║ ║ ║
╠═╣ ╠════════════════════════════════════════════╣ ║ ║ ║ ╔═╗ ╔═╗ ║
║ ║ ║ Ensure printer software is installed ║ ║ ║ ║ ║X║ ║X║ ║
╠═╣ ╠════════════════════════════════════════════╣ ╚═╬═╝ ║ ╚═╬═╝ ║
║ ║ ║ Check/replace ink ║ ║ ║ ║ ║
╠═╣ ╠════════════════════════════════════════════╬═╗ ║ ╔═╬═══╝ ║
║ ║ ║ Check for paper jam ║ ║ ║ ║X║ ║
╚═╩════════════╩════════════════════════════════════════════╩═╩═╩═╩═╩═══════╝)
(run-decision-table printer-troubleshooting-2dtable)</syntaxhighlight>
{{out}}
A trial run...
<pre>Printer does not print [y/n]?n
A red light is flashing [y/n]?y
Printer is unrecognized [y/n]?n
Suggested action: (Check/replace ink)</pre>
=={{header|Raku}}==
(formerly Perl 6)
<syntaxhighlight lang="raku" line>sub decide (@q, @s) {
my $bit = 2 ** [+] (1,2,4...*) Z* reverse @q.map: {
so prompt(.value ~ "? ") ~~ /:i ^y/;
}
say " $_" for @s.grep(*.key +& $bit)».value || "No clue!";
}
loop {
decide
(
"Y Y Y Y N N N N" => "Printer does not print",
"Y Y N N Y Y N N" => "A red light is flashing",
"Y N Y N Y N Y N" => "Printer is unrecognised",
),
(
:2<0_0_1_0_0_0_0_0> => "Check the power cable",
:2<1_0_1_0_0_0_0_0> => "Check the printer-computer cable",
:2<1_0_1_0_1_0_1_0> => "Ensure printer software is installed",
:2<1_1_0_0_1_1_0_0> => "Check/replace ink",
:2<0_1_0_1_0_0_0_0> => "Check for paper jam",
);
say '';
}</syntaxhighlight>
A bit of explanation: we pass in two pair lists for the questions and solutions; we ignore the keys of the questions, since they can be
generated by regarding them as a binary counter from right to left, with the least significant bit on the bottom. The <tt>@q.map</tt> runs the prompts and maps them to booleans
using case-insensitive matching. We reverse that list and zip multiply with powers of two to figure out which bit we're going to grep for. (The zip stops on the shorter list, which is always going to be the list of booleans, since the list of powers of two is infinite.) We sum up those powers of two using a <tt>[+]</tt> reduction metaoperator, which in this case gives us a number from 0 to 7. Then we take 2 to that power.
The solutions list of pairs is conveniently keyed on binary numbers written in colon radix notation, so we grep the keys containing the correct bit, then map the pair list to its values using a hyperoperator to parallelize it. Unlike in Perl 5, we can use <tt>||</tt> on lists as well as scalars to provide a default result if nothing matches.
{{out}}
<pre>Printer does not print? n
A red light is flashing? y
Printer is unrecognised? n
Check/replace ink
Printer does not print? y
A red light is flashing? n
Printer is unrecognised? y
Check the power cable
Check the printer-computer cable
Ensure printer software is installed
Printer does not print? n
A red light is flashing? n
Printer is unrecognised? n
No clue!
Printer does not print? ^C</pre>
=={{header|REXX}}==
This REXX example shows how one version of a decision table could be implemented,
There was additional support added to the code for:
::* a ''no solution found'' message
::* a ''don't care'' requirement (regarding the decision table)
::* a method of specifying requirements and not needing recoding for future queries
::* used a minimalistic way in expressing the decision table
::* extra prompting when there was a user response error
::* handles superfluous blanks and some punctuation.
::* displaying of a countdown so user knows length of interrogation
::* visual fidelity aids for postmortem analysis (as in logs)
::* a method of allowing the user to quit (opt-out of) the interrogation
<syntaxhighlight lang="rexx">/*REXX program demonstrates a (query) decision table and possible corrective actions.*/
Q.=; Q.1 = 'Does the printer not print?'
Q.2 = 'Is there a red light flashing on the printer?'
Q.3 = 'Is the printer unrecognized by the software?'
Q.0 = 3 /*the number of questions to be asked. */
action.= /* Y=yes N=no if character isn't a letter = don't care.*/
/* ┌─────◄── answer to 1st question (it can be in upper\lower\mixed case). */
/* │┌────◄── " " 2nd " " " " " " " " " */
/* ││┌───◄── " " 3rd " " " " " " " " " */
/* │││ */
/* ↓↓↓ */
action.1 = 'yny' ; pos.1 = "═════════ Check the power cable."
action.2 = 'y.y' ; pos.2 = "═════════ check the printer-computer cable."
action.3 = '..y' ; pos.3 = "═════════ Ensure printer software is installed."
action.4 = '.y.' ; pos.4 = "═════════ Check/replace ink."
action.5 = 'y.n' ; pos.5 = "═════════ Check for paper jam."
do i=1 while Q.i\==''; ans.i= asker(i) /*display the question, obtain response*/
end /*i*/
say /*display a blank line before questions*/
possible= 0 /*we'll be counting possible solutions.*/
do k=1 while action.k\=='' /*filter the answers via decision table*/
do j=1; d= substr(action.k, j, 1); upper d
jm= j//Q.0; if jm==0 then jm= Q.0
if d==' ' then leave
if \datatype(d, 'U') then iterate
if d\==ans.jm then iterate k
end /*j*/
say pos.k /*this could be a possible solution. */
possible= possible + 1 /*count number of possible solutions. */
end /*k*/
if possible==0 then say '═════════ There are no solutions for the information supplied.'
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
asker: arg ?; oops= 0; Qprefix= copies('─', 9) '(question' ? "of" Q.0') '
howTo = '(You can answer with a Yes or No [or Quit])'
do forever
if oops then do; say; say right(howTo, 79); say; oops= 0
end
say Qprefix Q.?; parse pull x /*ask question (after prompt)*/
x= strip(space(x), , .); parse upper var x u 1 u1 2 /*u1=1st character of answer.*/
if words(x)==0 then iterate /*Nothing entered? Try again.*/
if abbrev('QUIT', u,1) then exit /*user is tired of answering.*/
if (abbrev('YES', u) | abbrev("NO", u)) & words(x)==1 then return u1
say 'invalid response: ' x; oops= 1
end /*forever*/</syntaxhighlight>
{{out|output|text= (a screen scraping using a DOS prompt window for some of the possible responses):}}
('''decision.rex''' is the name of the REXX program that produced this output.)
<pre style="height:72ex">
D:\►rexx decision
───────── (question 1 of 3) Does the printer not print?
no ◄■■■■■■■■ user input.
───────── (question 2 of 3) Is there a red light flashing on the printer?
No ◄■■■■■■■■ user input.
───────── (question 3 of 3) Is the printer unrecognized by the software?
n ◄■■■■■■■■ user input.
═════════ There are no solutions for the information supplied.
D:\►rexx decision
───────── (question 1 of 3) Does the printer not print?
n ◄■■■■■■■■ user input.
───────── (question 2 of 3) Is there a red light flashing on the printer?
n ◄■■■■■■■■ user input.
───────── (question 3 of 3) Is the printer unrecognized by the software?
yes ◄■■■■■■■■ user input.
═════════ Ensure printer software is installed.
D:\►rexx decision
───────── (question 1 of 3) Does the printer not print?
n ◄■■■■■■■■ user input.
───────── (question 2 of 3) Is there a red light flashing on the printer?
Ye ◄■■■■■■■■ user input.
───────── (question 3 of 3) Is the printer unrecognized by the software?
n ◄■■■■■■■■ user input.
═════════ Check/replace ink.
D:\►rexx decision
───────── (question 1 of 3) Does the printer not print?
n ◄■■■■■■■■ user input.
───────── (question 2 of 3) Is there a red light flashing on the printer?
yes. ◄■■■■■■■■ user input.
───────── (question 3 of 3) Is the printer unrecognized by the software?
yes ◄■■■■■■■■ user input.
═════════ Ensure printer software is installed.
═════════ Check/replace ink.
D:\►rexx decision
───────── (question 1 of 3) Does the printer not print?
y ◄■■■■■■■■ user input.
───────── (question 2 of 3) Is there a red light flashing on the printer?
no ◄■■■■■■■■ user input.
───────── (question 3 of 3) Is the printer unrecognized by the software?
no ◄■■■■■■■■ user input.
═════════ Check for paper jam.
D:\►rexx decision
───────── (question 1 of 3) Does the printer not print?
y ◄■■■■■■■■ user input.
───────── (question 2 of 3) Is there a red light flashing on the printer?
n ◄■■■■■■■■ user input.
───────── (question 3 of 3) Is the printer unrecognized by the software?
y ◄■■■■■■■■ user input.
═════════ Check the power cable.
═════════ check the printer-computer cable.
═════════ Ensure printer software is installed.
D:\►rexx decision
───────── (question 1 of 3) Does the printer not print?
y ◄■■■■■■■■ user input.
───────── (question 2 of 3) Is there a red light flashing on the printer?
y ◄■■■■■■■■ user input.
───────── (question 3 of 3) Is the printer unrecognized by the software?
n ◄■■■■■■■■ user input.
═════════ Check/replace ink.
═════════ Check for paper jam.
D:\►rexx decision
───────── (question 1 of 3) Does the printer not print?
y ◄■■■■■■■■ user input.
───────── (question 2 of 3) Is there a red light flashing on the printer?
y ◄■■■■■■■■ user input.
───────── (question 3 of 3) Is the printer unrecognized by the software?
y ◄■■■■■■■■ user input.
═════════ check the printer-computer cable.
═════════ Ensure printer software is installed.
═════════ Check/replace ink.
D:\►
</pre>
=={{header|Ring}}==
<syntaxhighlight lang="ring">
# Project : Decision tables
see "The printer does not print (Y or N) "
give notprinting
see "A red light is upper(flashing) (Y or N) "
give flashing
see "The printer is unrecognized (Y or N) "
give notrecognized
if upper(notprinting) = "Y" and upper(flashing) = "Y" and upper(notrecognized) = "Y"
see "Check the printer-computer cable" + nl
see "Ensure printer software is installed" + nl
see "Check/replace ink"
elseif upper(notprinting) = "Y" and upper(flashing) = "Y" upper(notrecognized) = "N"
see "Check/replace ink" + nl
see "Check for paper jam" + nl
elseif upper(notprinting) = "Y" and upper(flashing) = "N" and upper(notrecognized) = "Y"
see "Check the power cable"
see "Check the printer-computer cable" + nl
see "Ensure printer software is installed" + nl
elseif upper(notprinting) = "Y" and upper(flashing) = "N" and upper(notrecognized) = "N"
see "Check for paper jam" + nl
elseif upper(notprinting) = "N" and upper(flashing) = "Y" and upper(notrecognized) = "Y"
see "Ensure printer software is installed" + nl
see "Check/replace ink" + nl
elseif upper(notprinting) = "N" and upper(flashing) = "Y" and upper(notrecognized) = "N"
see "Check/replace ink" + nl
elseif upper(notprinting) = "N" and upper(flashing) = "N" and upper(notrecognized) = "Y"
see "Ensure printer software is installed" + nl
elseif upper(notprinting) = "N" and upper(flashing) = "N" and upper(notrecognized) = "N"
see "no action found" + nl
else
see "invalid input: " + upper(notprinting) + " " + upper(flashing) + " " + upper(notrecognized) + nl
ok
</syntaxhighlight>
Output:
<pre>
The printer does not print (Y or N) y
A red light is upper(flashing) (Y or N) y
The printer is unrecognized (Y or N) y
Check the printer-computer cable
Ensure printer software is installed
Check/replace ink
</pre>
=={{header|Ruby}}==
<syntaxhighlight lang="ruby">class DecisionTable
def initialize(conditions, actions)
@conditions = conditions
@actions = []
@rules = []
actions.each {|action, ruleset| @actions << action; @rules << ruleset}
end
def run
puts "Conditions:"
index = ask_conditions
puts "Actions:"
results = @rules.each_with_index.inject([]) do |sum, (ruleset, idx)|
sum << @actions[idx] if ruleset[index] == 1
sum
end
results << "PC LOAD LETTER" if results.empty?
results.each {|res| puts " #{res}"}
puts ""
end
private
def ask_conditions
answers = @conditions.inject("") {|sum, c| sum + get_response(c)}
answers.to_i(2)
end
def get_response(prompt)
loop do
print " #{prompt}? "
case STDIN.gets.strip.downcase
when /^y/ then return "0"
when /^n/ then return "1"
end
end
end
end
dt = DecisionTable.new(
[
"Printer does not print", # Y Y Y Y N N N N
"A red light is flashing", # Y Y N N Y Y N N
"Printer is unrecognised", # Y N Y N Y N Y N
],
[
["Check the power cable", [0,0,1,0,0,0,0,0]],
["Check the printer-computer cable", [1,0,1,0,0,0,0,0]],
["Ensure printer software is installed", [1,0,1,0,1,0,1,0]],
["Check/replace ink", [1,1,0,0,1,1,0,0]],
["Check for paper jam", [0,1,0,1,0,0,0,0]],
]
)
loop {dt.run}</syntaxhighlight>
Example
<pre>Conditions:
Printer does not print? y
A red light is flashing? y
Printer is unrecognised? y
Actions:
Check the printer-computer cable
Ensure printer software is installed
Check/replace ink
Conditions:
Printer does not print? y
A red light is flashing? y
Printer is unrecognised? n
Actions:
Check/replace ink
Check for paper jam
Conditions:
Printer does not print? y
A red light is flashing? n
Printer is unrecognised? y
Actions:
Check the power cable
Check the printer-computer cable
Ensure printer software is installed
Conditions:
Printer does not print? y
A red light is flashing? n
Printer is unrecognised? n
Actions:
Check for paper jam
Conditions:
Printer does not print? n
A red light is flashing? y
Printer is unrecognised? y
Actions:
Ensure printer software is installed
Check/replace ink
Conditions:
Printer does not print? n
A red light is flashing? y
Printer is unrecognised? n
Actions:
Check/replace ink
Conditions:
Printer does not print? n
A red light is flashing? n
Printer is unrecognised? y
Actions:
Ensure printer software is installed
Conditions:
Printer does not print? n
A red light is flashing? n
Printer is unrecognised? n
Actions:
PC LOAD LETTER</pre>
=={{header|Scala}}==
{{trans|Java}}
<syntaxhighlight lang="scala">import java.io.{BufferedReader, InputStreamReader}
import scala.util.control.Breaks
object DecisionTables {
val conditions = List(
("Printer prints", "NNNNYYYY"),
("A red light is flashing", "YYNNYYNN"),
("Printer is recognized by computer", "NYNYNYNY")
)
val actions = List(
("Check the power cable", "NNYNNNNN"),
("Check the printer-computer cable", "YNYNNNNN"),
("Ensure printer software is installed", "YNYNYNYN"),
("Check/replace ink", "YYNNNYNN"),
("Check for paper jam", "NYNYNNNN")
)
def main(args: Array[String]): Unit = {
// var x = (1, 2)
// println(x)
// println(conditions)
// println(actions)
val nc = conditions.size
val na = actions.size
val nr = conditions.head._2.length
val np = 7
val br = new BufferedReader(new InputStreamReader(System.in))
println("Please answer the following questions with a y or n:")
val answers = Array.ofDim[Boolean](nc)
for (c <- 0 until nc) {
var input = ""
do {
printf(" %s ? ", conditions(c)._1)
input = br.readLine().toUpperCase
} while (input != "Y" && input != "N")
answers(c) = input == "Y"
}
println("\nRecommended actions(s)")
val Outer = new Breaks
val Inner = new Breaks
Outer.breakable {
for (r <- 0 until nr) {
var outer = true
Inner.breakable {
for (c <- 0 until nc) {
val yn = if (answers(c)) 'Y' else 'N'
if (conditions(c)._2(r) != yn) {
outer = false
Inner.break
}
}
}
if (outer) {
if (r == np) {
println(" None (no problem detected)")
} else {
for (action <- actions) {
if (action._2(r) == 'Y') {
printf(" %s\n", action._1)
}
}
}
Outer.break
}
}
}
}
}</syntaxhighlight>
{{out}}
<pre>Please answer the following questions with a y or n:
Printer prints ? y
A red light is flashing ? y
Printer is recognized by computer ? y
Recommended actions(s)
Check/replace ink</pre>
=={{header|Sidef}}==
{{trans|Raku}}
<syntaxhighlight lang="ruby">func decide (q, s) {
var bits = q.map { |p|
read("#{p.value}? ", String) ~~ /^y/i ? 1 : 0
}
var n = with (0) { |t|
bits.each { |b|
t <<= 1
t |= b
}
1 << t
}
s.grep { .key & n }.map{ .value }.each { |ans|
say " #{ans}"
}
}
loop {
decide(
[
Pair("Y Y Y Y N N N N", "Printer does not print"),
Pair("Y Y N N Y Y N N", "A red light is flashing"),
Pair("Y N Y N Y N Y N", "Printer is unrecognised"),
],
[
Pair(0b0_0_1_0_0_0_0_0, "Check the power cable"),
Pair(0b1_0_1_0_0_0_0_0, "Check the printer-computer cable"),
Pair(0b1_0_1_0_1_0_1_0, "Ensure printer software is installed"),
Pair(0b1_1_0_0_1_1_0_0, "Check/replace ink"),
Pair(0b0_1_0_1_0_0_0_0, "Check for paper jam"),
]
)
say ''
}</syntaxhighlight>
{{out}}
<pre>
Printer does not print? y
A red light is flashing? n
Printer is unrecognised? n
Check for paper jam
Printer does not print? n
A red light is flashing? n
Printer is unrecognised? y
Ensure printer software is installed
Printer does not print? y
A red light is flashing? y
Printer is unrecognised? n
Check/replace ink
Check for paper jam
Printer does not print? n
A red light is flashing? y
Printer is unrecognised? y
Ensure printer software is installed
Check/replace ink
Printer does not print? ^C
</pre>
=={{header|Tcl}}==
<
#http://rosettacode.org/wiki/Keyboard_Input/Obtain_a_Y_or_N_response#Tcl
Line 320 ⟶ 2,893:
}
}
}</
Demonstration:
<
"Printer does not print"
"A red light is flashing"
Line 333 ⟶ 2,906:
"Check for paper jam" {0 1 0 1}
}
printerDiagnosisTable consult</
Output:
<pre>
Line 341 ⟶ 2,914:
Ensure printer software is installed
Check/replace ink
</pre>
=={{header|Wren}}==
{{trans|Kotlin}}
{{libheader|Wren-str}}
<syntaxhighlight lang="wren">import "io" for Stdin, Stdout
import "./str" for Str
var conditions = [
["Printer prints" , "NNNNYYYY"],
["A red light is flashing" , "YYNNYYNN"],
["Printer is recognized by computer", "NYNYNYNY"]
]
var actions = [
["Check the power cable" , "NNYNNNNN"],
["Check the printer-computer cable" , "YNYNNNNN"],
["Ensure printer software is installed", "YNYNYNYN"],
["Check/replace ink" , "YYNNNYNN"],
["Check for paper jam" , "NYNYNNNN"]
]
var nc = conditions.count
var na = actions.count
var nr = conditions[0][1].count // number of rules
var np = 7 // index of 'no problem' rule
System.print("Please answer the following questions with a y or n:")
var answers = List.filled(nc, false)
for (c in 0...nc) {
var input
while (true) {
System.write(" %(conditions[c][0]) ? ")
Stdout.flush()
input = Str.upper(Stdin.readLine())
if (input == "Y" || input == "N") break
}
answers[c] = (input == "Y")
}
System.print("\nRecommended action(s):")
for (r in 0...nr) {
var outer = false
for (c in 0...nc) {
var yn = answers[c] ? "Y" : "N"
if (conditions[c][1][r] != yn) {
outer = true
break
}
}
if (!outer) {
if (r == np) {
System.print(" None (no problem detected)")
} else {
for (a in 0...na) {
if (actions[a][1][r] == "Y") System.print(" %(actions[a][0])")
}
}
break
}
}</syntaxhighlight>
{{out}}
Sample input/output:
<pre>
Please answer the following questions with a y or n:
Printer prints ? n
A red light is flashing ? n
Printer is recognized by computer ? n
Recommended action(s):
Check the power cable
Check the printer-computer cable
Ensure printer software is installed
</pre>
=={{header|XPL0}}==
{{trans|Wren}}
<syntaxhighlight lang "XPL0">include xpllib; \for ToUpper, Print
int Conditions, Actions, NC, NA, NR, NP, Answers(3), Input, Outer, YN, R, C, A;
char S;
[Conditions:= [
["Printer prints" , "NNNNYYYY"],
["A red light is flashing" , "YYNNYYNN"],
["Printer is recognized by computer", "NYNYNYNY"]
];
Actions:= [
["Check the power cable" , "NNYNNNNN"],
["Check the printer-computer cable" , "YNYNNNNN"],
["Ensure printer software is installed", "YNYNYNYN"],
["Check/replace ink" , "YYNNNYNN"],
["Check for paper jam" , "NYNYNNNN"]
];
NC:= 3;
NA:= 5;
NR:= 8; \number of rules
NP:= 7; \index of 'no problem' rule
Print("Please answer the following questions with a y or n:\n");
for C:= 0 to NC-1 do
[loop [Print(" %s ? ", Conditions(C,0));
OpenI(0);
Input:= ToUpper(ChIn(0));
if Input = ^Y or Input = ^N then quit;
];
Answers(C):= Input = ^Y;
];
Print("\nRecommended action(s):\n");
for R:= 0 to NR-1 do
[Outer:= false;
for C:= 0 to NC-1 do
[YN:= if Answers(C) then ^Y else ^N;
S:= Conditions(C,1); \to access character bytes not integers
if S(R) # YN then
[Outer:= true;
C:= NC; \break
];
];
if not Outer then
[if R = NP then
Print(" None (no problem detected)\n")
else [for A:= 0 to NA-1 do
[S:= Actions(A,1);
if S(R) = ^Y then
Print(" %s\n", Actions(A,0));
];
];
R:= NR; \break
];
];
]</syntaxhighlight>
{{out}}
<pre>
Please answer the following questions with a y or n:
Printer prints ? n
A red light is flashing ? n
Printer is recognized by computer ? n
Recommended action(s):
Check the power cable
Check the printer-computer cable
Ensure printer software is installed
</pre>
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