Range expansion
You are encouraged to solve this task according to the task description, using any language you may know.
A format for expressing an ordered list of integers is to use a comma separated list of either
- individual integers
- Or a range of integers denoted by the starting integer separated from the end integer in the range by a dash, '-'. (The range includes all integers in the interval including both endpoints)
- The range syntax is to be used only for, and for every range that expands to more than two values.
Example
The list of integers:
- -6, -3, -2, -1, 0, 1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
Is accurately expressed by the range expression:
- -6,-3-1,3-5,7-11,14,15,17-20
(And vice-versa).
- The task
Expand the range description:
- -6,-3--1,3-5,7-11,14,15,17-20
Note that the second element above, is the range from minus 3 to minus 1.
C.f. Range extraction
Ada
The function Expand takes a string and returns a corresponding array of integers. Upon syntax errors Constraint_Error is propagated: <lang Ada>with Ada.Text_IO; use Ada.Text_IO; procedure Test_Range_Expansion is
type Sequence is array (Positive range <>) of Integer;
function Expand (Text : String) return Sequence is
To : Integer := Text'First;
Count : Natural := 0;
Low : Integer;
function Get return Integer is
From : Integer := To;
begin
if Text (To) = '-' then
To := To + 1;
end if;
while To <= Text'Last loop
case Text (To) is
when ',' | '-' => exit;
when others => To := To + 1;
end case;
end loop;
return Integer'Value (Text (From..To - 1));
end Get;
begin
while To <= Text'Last loop -- Counting items of the list
Low := Get;
if To > Text'Last or else Text (To) = ',' then
Count := Count + 1;
else
To := To + 1;
Count := Count + Get - Low + 1;
end if;
To := To + 1;
end loop;
return Result : Sequence (1..Count) do
Count := 0;
To := Text'First;
while To <= Text'Last loop -- Filling the list
Low := Get;
if To > Text'Last or else Text (To) = ',' then
Count := Count + 1;
Result (Count) := Low;
else
To := To + 1;
for Item in Low..Get loop
Count := Count + 1;
Result (Count) := Item;
end loop;
end if;
To := To + 1;
end loop;
end return;
end Expand;
procedure Put (S : Sequence) is
First : Boolean := True;
begin
for I in S'Range loop
if First then
First := False;
else
Put (',');
end if;
Put (Integer'Image (S (I)));
end loop;
end Put;
begin
Put (Expand ("-6,-3--1,3-5,7-11,14,15,17-20"));
end Test_Range_Expansion;</lang>
- Output:
-6,-3,-2,-1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
ALGOL 68
<lang algol68>MODE YIELDINT = PROC(INT)VOID;
MODE RANGE = STRUCT(INT lwb, upb); MODE RANGEINT = UNION(RANGE, INT);
OP SIZEOF = ([]RANGEINT list)INT: (
- determine the length of the output array #
INT upb := LWB list - 1;
FOR key FROM LWB list TO UPB list DO
CASE list[key] IN
(RANGE value): upb +:= upb OF value - lwb OF value + 1,
(INT): upb +:= 1
ESAC
OD;
upb
);
PROC gen range expand = ([]RANGEINT list, YIELDINT yield)VOID:
FOR key FROM LWB list TO UPB list DO
CASE list[key] IN
(RANGE range): FOR value FROM lwb OF range TO upb OF range DO yield(value) OD,
(INT int): yield(int)
ESAC
OD;
PROC range expand = ([]RANGEINT list)[]INT: (
[LWB list: LWB list + SIZEOF list - 1]INT out; INT upb := LWB out - 1;
- FOR INT value IN # gen range expand(list, # ) DO #
- (INT value)VOID:
out[upb +:= 1] := value
- OD #);
out
);
test:(
[]RANGEINT list = (-6, RANGE(-3, -1), RANGE(3, 5), RANGE(7, 11), 14, 15, RANGE(17, 20)); print((range expand(list), new line))
)
- converts string containing a comma-separated list of ranges and values to a []RANGEINT #
OP TORANGE = ( STRING s )[]RANGEINT: BEGIN
# counts the number of elements - one more than the number of commas # # and so assumes there is always at least one element # PROC count elements = INT: BEGIN
INT elements := 1;
FOR pos FROM LWB s TO UPB s
DO
IF s[ pos ] = ","
THEN
elements +:= 1
FI
OD;
# RESULT #
elements
END; # count elements #
REF[]RANGEINT result = HEAP [ 1 : count elements ]RANGEINT;
# does the actual parsing - assumes the string is syntatically valid and doesn't check for errors # # - in particular, a string with no elements will cause problems, as will space characters in the string # PROC parse range string = []RANGEINT: BEGIN
INT element := 0;
INT str pos := 1;
PROC next = VOID: str pos +:= 1;
PROC curr char = CHAR: IF str pos > UPB s THEN "?" ELSE s[ str pos ] FI;
PROC have minus = BOOL: curr char = "-";
PROC have digit = BOOL: curr char >= "0" AND curr char <= "9";
# parses a number out of the string #
# the number must be a sequence of digits with an optional leading minus sign #
PROC get number = INT:
BEGIN
INT number := 0;
INT sign multiplier = IF have minus
THEN
# negaive number #
# skip the sign #
next;
-1
ELSE
# positive number #
1
FI;
WHILE curr char >= "0" AND curr char <= "9"
DO
number *:= 10;
number +:= ( ABS curr char - ABS "0" );
next
OD;
# RESULT #
number * sign multiplier
END; # get number #
# main parsing #
WHILE str pos <= UPB s
DO
CHAR c = curr char;
IF have minus OR have digit
THEN
# have the start of a number #
INT from value = get number;
element +:= 1;
IF NOT have minus
THEN
# not a range #
result[ element ] := from value
ELSE
# have a range #
next;
INT to value = get number;
result[ element ] := RANGE( from value, to value )
FI
ELSE
# should be a comma #
next
FI
OD;
# RESULT #
result
END; # parse range string #
- RESULT #
parse range string
END; # TORANGE #
- converts a []INT to a comma separated string of the elements #
OP TOSTRING = ( []INT values )STRING: BEGIN
# converts an integer to a string #
OP TOSTRING = ( INT value )STRING:
BEGIN
STRING result := "";
INT n := ABS value;
WHILE
REPR ( ( n MOD 10 ) + ABS "0" ) PLUSTO result;
n OVERAB 10;
n > 0
DO
SKIP
OD;
# RESULT #
IF value < 0 THEN "-" ELSE "" FI + result
END; # TOSTRING #
STRING result := ""; STRING separator := "";
FOR pos FROM LWB values TO UPB values
DO
result +:= ( separator + TOSTRING values[ pos ] );
separator := ","
OD;
- RESULT #
result
END; # TOSTRING #
test:(
print( ( TOSTRING range expand( TORANGE "-6,-3--1,3-5,7-11,14,15,17-20" ), newline ) )
) </lang>
- Output:
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
AutoHotkey
<lang AutoHotkey>msgbox % expand("-6,-3--1,3-5,7-11,14,15,17-20")
expand( range ) {
p := 0
while p := RegExMatch(range, "\s*(-?\d++)(?:\s*-\s*(-?\d++))?", f, p+1+StrLen(f))
loop % (f2 ? f2-f1 : 0) + 1
ret .= "," (A_Index-1) + f1
return SubStr(ret, 2)
}</lang>
AWK
<lang awk>#!/usr/bin/awk -f BEGIN { FS=","; }
{ s=""; for (i=1; i<=NF; i++) { expand($i); } print substr(s,2); }
function expand(a) { idx = match(a,/[0-9]-/); if (idx==0) { s = s","a; return; }
start= substr(a,1, idx)+0; stop = substr(a,idx+2)+0; for (m = start; m <= stop; m++) { s = s","m; } return; } </lang>
Usage: echo -6,-3--1,3-5,7-11,14,15,17-20 | gawk -f ./range_expansion.awk -6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
BBC BASIC
<lang bbcbasic> PRINT FNrangeexpand("-6,-3--1,3-5,7-11,14,15,17-20")
END
DEF FNrangeexpand(r$)
LOCAL i%, j%, k%, t$
REPEAT
i% = INSTR(r$, "-", i%+1)
IF i% THEN
j% = i%
WHILE MID$(r$,j%-1,1)<>"," AND j%<>1
j% -= 1
ENDWHILE
IF i%>j% IF MID$(r$,j%,i%-j%)<>STRING$(i%-j%," ") THEN
t$ = ""
FOR k% = VALMID$(r$,j%) TO VALMID$(r$,i%+1)-1
t$ += STR$(k%) + ","
NEXT
r$ = LEFT$(r$,j%-1) + t$ + MID$(r$,i%+1)
i% = j% + LEN(t$) + 2
ENDIF
ENDIF
UNTIL i% = 0
= r$</lang>
Output:
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
Bracmat
<lang bracmat> ( expandRanges
= a b L
. @( !arg
: (#(?a:?b)|#?a "-" #?b)
(:?L|"," [%(expandRanges$!sjt:?L))
)
& whl
' ( (!L:&!b|(!b,!L))
: ?L
& -1+!b:~<!a:?b
)
& !L
|
)
& out$(str$(expandRanges$"-6,-3--1,3-5,7-11,14,15,17-20")) </lang> Output:
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
C
Recursive descent parser. <lang c>#include <stdio.h>
- include <stdlib.h>
- include <ctype.h>
/* BNFesque rangelist := (range | number) [',' rangelist] range := number '-' number */
int get_list(const char *, char **); int get_rnge(const char *, char **);
/* parser only parses; what to do with parsed items is up to
- the add_number and and_range functions */
void add_number(int x); int add_range(int x, int y);
- define skip_space while(isspace(*s)) s++
- define get_number(x, s, e) (x = strtol(s, e, 10), *e != s)
int get_list(const char *s, char **e) { int x; while (1) { skip_space; if (!get_rnge(s, e) && !get_number(x, s, e)) break; s = *e;
skip_space; if ((*s) == '\0') { putchar('\n'); return 1; } if ((*s) == ',') { s++; continue; } break; } *(const char **)e = s; printf("\nSyntax error at %s\n", s); return 0; }
int get_rnge(const char *s, char **e) { int x, y; char *ee; if (!get_number(x, s, &ee)) return 0; s = ee;
skip_space; if (*s != '-') { *(const char **)e = s; return 0; } s++; if(!get_number(y, s, e)) return 0; return add_range(x, y); }
void add_number(int x) { printf("%d ", x); }
int add_range(int x, int y) { if (y <= x) return 0; while (x <= y) printf("%d ", x++); return 1; }
int main() { char *end;
/* this is correct */ if (get_list("-6,-3--1,3-5,7-11,14,15,17-20", &end)) puts("Ok");
/* this is not. note the subtle error: "-6 -3" is parsed * as range(-6, 3), so synax error comes after that */ get_list("-6 -3--1,3-5,7-11,14,15,17-20", &end);
return 0; }</lang>
- Output:
-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20 Ok -6 -5 -4 -3 -2 -1 0 1 2 3 Syntax error at --1,3-5,7-11,14,15,17-20
C#
<lang csharp>using System; using System.Collections.Generic; using System.Linq; using System.Text.RegularExpressions;
class Program {
static void Main(string[] args)
{
var rangeString = "-6,-3--1,3-5,7-11,14,15,17-20";
var matches = Regex.Matches(rangeString, @"(?<f>-?\d+)-(?-?\d+)|(-?\d+)");
var values = new List<string>();
foreach (var m in matches.OfType<Match>())
{
if (m.Groups[1].Success)
{
values.Add(m.Value);
continue;
}
var start = Convert.ToInt32(m.Groups["f"].Value);
var end = Convert.ToInt32(m.Groups["s"].Value) + 1;
values.AddRange(Enumerable.Range(start, end - start).Select(v => v.ToString()));
}
Console.WriteLine(string.Join(", ", values));
}
}</lang>
C++
<lang cpp>#include <iostream>
- include <sstream>
- include <iterator>
- include <climits>
- include <deque>
// parse a list of numbers with ranges // // arguments: // is: the stream to parse // out: the output iterator the parsed list is written to. // // returns true if the parse was successful. false otherwise template<typename OutIter>
bool parse_number_list_with_ranges(std::istream& is, OutIter out)
{
int number;
// the list always has to start with a number
while (is >> number)
{
*out++ = number;
char c;
if (is >> c)
switch(c)
{
case ',':
continue;
case '-':
{
int number2;
if (is >> number2)
{
if (number2 < number)
return false;
while (number < number2)
*out++ = ++number;
char c2;
if (is >> c2)
if (c2 == ',')
continue;
else
return false;
else
return is.eof();
}
else
return false;
}
default:
return is.eof();
}
else
return is.eof();
}
// if we get here, something went wrong (otherwise we would have
// returned from inside the loop)
return false;
}
int main() {
std::istringstream example("-6,-3--1,3-5,7-11,14,15,17-20");
std::deque<int> v;
bool success = parse_number_list_with_ranges(example, std::back_inserter(v));
if (success)
{
std::copy(v.begin(), v.end()-1,
std::ostream_iterator<int>(std::cout, ","));
std::cout << v.back() << "\n";
}
else
std::cout << "an error occured.";
}</lang>
- Output:
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
Clojure
There is a split method in clojure.contrib, but I don't know if it is able to skip first character to so that (split "-8--8") => (-8 -8).
<lang clojure>(defn split [s sep]
(defn skipFirst x & xs :as s
(cond (empty? s) [nil nil] (= x sep) [x xs] true [nil s]))
(loop [lst '(), s s]
(if (empty? s) (reverse lst) (let [[hd trunc] (skipFirst s) [word news] (split-with #(not= % sep) trunc) cWord (cons hd word)] (recur (cons (apply str cWord) lst) (apply str (rest news)))))))
(defn parseRange x & xs :as s
(if (some #(= % \-) xs)
(let [[r0 r1] (split s \-)] (range (read-string r0) (inc (read-string r1)))) (list (read-string (str s))))))
(defn rangeexpand [s]
(flatten (map parseRange (split s \,))))
> (rangeexpand "-6,-3--1,3-5,7-11,14,15,17-20") (-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20)</lang>
Common Lisp
<lang lisp>(defun expand-ranges (string)
(loop
with prevnum = nil
for idx = 0 then (1+ nextidx)
for (number nextidx) = (multiple-value-list
(parse-integer string
:start idx :junk-allowed t))
append (cond
(prevnum
(prog1
(loop for i from prevnum to number
collect i)
(setf prevnum nil)))
((and (< nextidx (length string))
(char= (aref string nextidx) #\-))
(setf prevnum number)
nil)
(t
(list number)))
while (< nextidx (length string))))
CL-USER> (expand-ranges "-6,-3--1,3-5,7-11,14,15,17-20") (-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20)</lang>
D
<lang d>import std.stdio, std.regex, std.conv, std.range, std.algorithm;
enum rangeEx = (string s) /*pure*/ => s.matchAll(`(-?\d+)-?(-?\d+)?,?`)
.map!q{ a[1].to!int.iota(a[1 + !a[2].empty].to!int + 1) }.join;
void main() {
"-6,-3--1,3-5,7-11,14,15,17-20".rangeEx.writeln;
}</lang>
- Output:
[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]
Erlang
<lang Erlang> -module( range ).
-export( [expansion/1, task/0] ).
expansion( String ) ->
lists:flatten( [expansion_individual(io_lib:fread("~d", X)) || X <- string:tokens(String, ",")] ).
task() ->
io:fwrite( "~p~n", [expansion("-6,-3--1,3-5,7-11,14,15,17-20")] ).
expansion_individual( {ok, [N], []} ) -> N; expansion_individual( {ok, [Start], "-" ++ Stop_string} ) -> lists:seq( Start, erlang:list_to_integer(Stop_string) ). </lang>
- Output:
34> range:task(). [-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20]
Forth
<lang forth>: >snumber ( str len -- 'str 'len n )
0. 2swap over c@ [char] - = if 1 /string >number 2swap drop negate else >number 2swap drop then ;
- expand ( str len -- )
begin dup while
>snumber >r
dup if over c@ [char] - = if
1 /string
>snumber r> over >r
do i . loop
then then
dup if over c@ [char] , = if
1 /string
then then
r> .
repeat 2drop ;
s" -6,-3--1,3-5,7-11,14,15,17-20" expand</lang>
F#
<lang fsharp>open System.Text.RegularExpressions
// simplify regex matching with an active pattern let (|Regexp|_|) pattern txt =
match Regex.Match(txt, pattern) with | m when m.Success -> [for g in m.Groups -> g.Value] |> List.tail |> Some | _ -> None
// Parse and expand a single range description. // string -> int list let parseRange r =
match r with | Regexp @"^(-?\d+)-(-?\d+)$" [first; last] -> [int first..int last] | Regexp @"^(-?\d+)$" [single] -> [int single] | _ -> failwithf "illegal range format: %s" r
let expand (desc:string) =
desc.Split(',')
|> List.ofArray
|> List.collect parseRange
printfn "%A" (expand "-6,-3--1,3-5,7-11,14,15,17-20")</lang>
- Output:
[-6; -3; -2; -1; 3; 4; 5; 7; 8; 9; 10; 11; 14; 15; 17; 18; 19; 20]
Go
A version rather strict with input <lang go>package main
import (
"fmt" "strconv" "strings"
)
const input = "-6,-3--1,3-5,7-11,14,15,17-20"
func main() {
fmt.Println("range:", input)
var r []int
var last int
for _, part := range strings.Split(input, ",") {
if i := strings.Index(part[1:], "-"); i == -1 {
n, err := strconv.Atoi(part)
if err != nil {
fmt.Println(err)
return
}
if len(r) > 0 {
if last == n {
fmt.Println("duplicate value:", n)
return
} else if last > n {
fmt.Println("values not ordered:", last, ">", n)
return
}
}
r = append(r, n)
last = n
} else {
n1, err := strconv.Atoi(part[:i+1])
if err != nil {
fmt.Println(err)
return
}
n2, err := strconv.Atoi(part[i+2:])
if err != nil {
fmt.Println(err)
return
}
if n2 < n1+2 {
fmt.Println("invalid range:", part)
return
}
if len(r) > 0 {
if last == n1 {
fmt.Println("duplicate value:", n1)
return
} else if last > n1 {
fmt.Println("values not ordered:", last, ">", n1)
return
}
}
for i = n1; i <= n2; i++ {
r = append(r, i)
}
last = n2
}
}
fmt.Println("expanded:", r)
}</lang>
Groovy
Ad Hoc Solution:
- translate the task's range syntax into Groovy range syntax
- wrap with list delimiters
- evaluate the script expression
- flatten the nested lists
- express as a string
- unwrap the list delimiters
<lang groovy>def expandRanges = { compressed ->
Eval.me('['+compressed.replaceAll(~/(\d)-/, '$1..')+']').flatten().toString()[1..-2]
}</lang> Test: <lang groovy>def s = '-6,-3--1,3-5,7-11,14,15,17-20' println (expandRanges(s))</lang>
- Output:
-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
Haskell
Given either of the below implementations of expandRange:
<lang haskell>> expandRange "-6,-3--1,3-5,7-11,14,15,17-20"
[-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20]</lang>
With conventional list processing
<lang haskell>expandRange :: String -> [Int] expandRange = concatMap f . split ','
where f str@(c : cs) | '-' `elem` cs = [read (c : a) .. read b]
| otherwise = [read str]
where (a, _ : b) = break (== '-') cs
split :: Eq a => a -> [a] -> a split delim [] = [] split delim l = a : split delim (dropWhile (== delim) b)
where (a, b) = break (== delim) l</lang>
With a parser
<lang haskell>import Control.Monad import Text.ParserCombinators.Parsec
expandRange :: String -> [Int] expandRange s = case parse rangeParser "" s of Right l -> l
rangeParser :: Parser [Int] rangeParser = liftM concat $ item `sepBy` char ','
where item = do
n1 <- num
n2 <- option n1 $ char '-' >> num
return [n1 .. n2]
num :: Parser Int
num = liftM read $ liftM2 (++)
(option "" $ string "-")
(many1 digit)</lang>
Icon and Unicon
<lang Icon>procedure main() s := "-6,-3--1,3-5,7-11,14,15,17-20" write("Input string := ",s) write("Expanded list := ", list2string(range_expand(s)) | "FAILED") end
procedure range_expand(s) #: return list of integers extracted from an ordered string representation local R,low,high R := []
s ? until pos(0) do {
put(R,low := integer(tab(upto(',-')|0))| fail) # get lower bound
if ="-" || (high := integer(tab(find(",")|0))|fail) then
until low = high do put(R,low +:= 1) # find range
=","
}
return R end
procedure list2string(L) #: helper function to convert a list to a string local s
every (s := "[ ") ||:= !L || " " return s || "]"
end</lang>
- Output:
Input string := -6,-3--1,3-5,7-11,14,15,17-20 Expanded list := [ -6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20 ]
J
<lang j>require'strings' to=: [ + i.@>:@-~ num=: _&". normaliz=: rplc&(',-';',_';'--';'-_')@,~&',' subranges=:<@(to/)@(num;._2)@,&'-';._1 rngexp=: ;@subranges@normaliz</lang>
- Example:
<lang j> rngexp '-6,-3--1,3-5,7-11,14,15,17-20' _6 _3 _2 _1 3 4 5 7 8 9 10 11 14 15 17 18 19 20</lang>
Notes:
to: given two numbers (left: start of range, right: end of range) return the corresponding range
num: given the string representation of a number, returns the number
normaliz: given the task required string representing a sequence of ranges, create a fresh copy with fewer micro ambiguities: All subranges are preceded by a comma. Negative numbers use a different character ('_') than the continuous range character ('-').
subranges: given the result of normaliz, return a sequence of boxes (one box for each comma). Each box contains the subrange which is described after its comma.
Note that to/ is an identity function when applied to a single number. This is because (verb/) inserts the verb between each number (or each item in a list), and this is an identity function on a single number, regardless of any definition of the verb.
Java
<lang java>import java.util.*; import java.util.regex.*;
class Range implements Enumeration {
private int clower, cupper; private int value; private boolean inrange; private Scanner ps = null; private String ss;
private static String del = "\\s*,\\s*";
public Range(String s) {
ss = s;
reset();
}
public boolean hasMoreElements() {
return (inrange && (value >= clower && value <= cupper)) || ps.hasNext();
}
public Object nextElement() throws NoSuchElementException {
if (!hasMoreElements())
throw new NoSuchElementException();
if (inrange && (value >= clower && value <= cupper)) {
value++;
return value-1;
}
inrange = false;
String n = ps.next();
if (n.matches("[+-]?\\d+-[+-]?\\d+")) {
Scanner ls = new Scanner(n);
ls.findInLine("([+-]?\\d+)-([+-]?\\d+)");
MatchResult r = ls.match();
clower = Integer.parseInt(r.group(1));
cupper = Integer.parseInt(r.group(2));
value = clower+1;
inrange = true;
ls.close();
return clower;
}
return Integer.parseInt(n);
}
public void reset() {
if (ps != null)
ps.close();
ps = new Scanner(ss).useDelimiter(del);
inrange = false;
}
protected void finalize() throws Throwable {
ps.close();
super.finalize();
}
}
class rangexp {
public static void main(String[] args) {
Range r = new Range("-6,-3--1,3-5,7-11,14,15,17-20");
while (r.hasMoreElements()) {
System.out.print(r.nextElement() + " ");
}
System.out.println();
}
}</lang>
JavaScript
Spidermonkey version
<lang javascript>#!/usr/bin/env js
function main() {
print(rangeExpand('-6,-3--1,3-5,7-11,14,15,17-20'));
}
function rangeExpand(rangeExpr) {
function getFactors(term) {
var matches = term.match(/(-?[0-9]+)-(-?[0-9]+)/);
if (!matches) return {first:Number(term)};
return {first:Number(matches[1]), last:Number(matches[2])};
}
function expandTerm(term) {
var factors = getFactors(term);
if (factors.length < 2) return [factors.first];
var range = [];
for (var n = factors.first; n <= factors.last; n++) {
range.push(n);
}
return range;
}
var result = [];
var terms = rangeExpr.split(/,/);
for (var t in terms) {
result = result.concat(expandTerm(terms[t]));
}
return result;
}
main(); </lang>
Example output:
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
Julia
<lang Julia>slurp(s) = readcsv(IOBuffer(s*","))
conv(s) = colon(map(int,(match(r"^(-?\d+)-(-?\d+)$", s).captures))...)
expand(s) = mapreduce(x -> isa(x,Number)? int(x): conv(x), vcat, slurp(s))</lang>
- Output:
julia> show(expand("-6,-3--1,3-5,7-11,14,15,17-20"))
[-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20]K
<lang k>grp : {1_'(&x=*x)_ x:",",x} pos : {:[3=l:#p:&"-"=x;0,p@1;2=l;p;0=*p;,0;0,p]} conv: 0${(x;1_ y)}/'{(pos x)_ x}' expd: {,/@[x;&2=#:'x;{(*x)+!1+,/-':x}]} rnge: {expd@conv grp x}</lang>
- Example:
<lang k> rnge "-6,-3--1,3-5,7-11,14,15,17-20" -6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20</lang>
Lasso
<lang lasso>define range_expand(expression::string) => {
local(parts) = regexp(`^(-?\d+)-(-?\d+)$`)
return (
with elm in #expression->split(`,`)
let isRange = #parts->setInput(#elm)&matches
select #isRange
? (integer(#parts->matchString(1)) to integer(#parts->matchString(2)))->asString
| integer(#elm)->asString
)->join(', ')
}
range_expand(`-6,-3--1,3-5,7-11,14,15,17-20`)</lang>
- Output:
-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
Liberty BASIC
<lang lb>print ExpandRange$( "-6,-3--1,3-5,7-11,14,15,17-20") end
function ExpandRange$( compressed$)
for i = 1 to ItemCount( compressed$, ",")
item$ = word$( compressed$, i, ",")
dash = instr( item$, "-", 2) 'dash that is not the first character, is a separator
if dash then
for k = val( left$( item$, dash - 1)) to val( mid$( item$, dash + 1))
ExpandRange$ = ExpandRange$ + str$( k) + ","
next k
else
ExpandRange$ = ExpandRange$ + item$ + ","
end if
next i
ExpandRange$ = left$( ExpandRange$, len( ExpandRange$) - 1)
end function
function ItemCount( list$, separator$)
while word$(list$, ItemCount + 1, separator$) <> ""
ItemCount = ItemCount + 1
wend
end function</lang>
- Output:
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
Maple
<lang Maple> ExpandRanges := proc( s :: string )
uses StringTools;
local DoOne := proc( input )
uses StringTools;
local lo, hi, pos;
if IsDigit( input ) or input[ 1 ] = "-"
and IsDigit( input[ 2 .. -1 ] ) then
parse( input )
else
pos := Search( "--", input );
if pos > 0 then
lo := input[ 1 .. pos - 1 ];
hi := input[ 1 + pos .. -1 ];
elif input[ 1 ] = "-" then
pos := FirstFromLeft( "-", input[ 2 .. -1 ] );
if pos = 0 then
lo := input;
hi := lo
else
lo := input[ 1 .. pos ];
hi := input[ 2 + pos .. -1 ];
end if;
else
pos := FirstFromLeft( "-", input );
if pos = 0 then
error "incorrect syntax"
end if;
lo := input[ 1 .. pos - 1 ];
hi := input[ 1 + pos .. -1 ];
end if;
lo := parse( lo );
hi := parse( hi );
seq( lo .. hi )
end if
end proc:
map( DoOne, map( Trim, Split( s, "," ) ) )
end proc: </lang> Running this on the example input we get the following. <lang Maple> > rng := "-6,-3--1,3-5,7-11,14,15,17-20": > ExpandRanges( rng );
[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]
</lang> Here is an additional example which my first attempt got wrong. <lang Maple> > rng := "-6,-3-1,3-5,7-11,14,15,17-20": > ExpandRanges( rng ); [-6, -3, -2, -1, 0, 1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20] </lang>
Mathematica
<lang Mathematica>rangeexpand[ rng_ ] := Module[ { step1 }, step1 = StringSplit[StringReplacePart[rng,"S",StringPosition[ rng,DigitCharacter~~"-"] /. {x_,y_} -> {y,y}],","]; Flatten@ToExpression/@Quiet@StringReplace[step1,x__~~"S"~~y__->"Range["<>x<>","<>y<>"]"] ]</lang>
- Example:
rangeexpand["-6,-3--1,3-5,7-11,14,15,17-20"]
{-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20}MATLAB / Octave
<lang MATLAB>function L=range_expansion(S) % Range expansion if nargin < 1; S='[]'; end
if ~all(isdigit(S) | (S=='-') | (S==',') | isspace(S)) error 'invalid input'; end ixr = find(isdigit(S(1:end-1)) & S(2:end) == '-')+1; S(ixr)=':'; S=['[',S,']']; L=eval(S);</lang> Usage:
range_expansion('-6,-3--1,3-5,7-11,14,15,17-20 ')
ans =
-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20
MUMPS
<lang MUMPS>RANGEXP(X) ;Integer range expansion
NEW Y,I,J,X1,H SET Y="" FOR I=1:1:$LENGTH(X,",") DO .S X1=$PIECE(X,",",I) FOR Q:$EXTRACT(X1)'=" " S X1=$EXTRACT(X1,2,$LENGTH(X1)) ;clean up leading spaces .SET H=$FIND(X1,"-")-1 .IF H=1 SET H=$FIND(X1,"-",(H+1))-1 ;If the first value is negative ignore that "-" .IF H<0 SET Y=$SELECT($LENGTH(Y)=0:Y_X1,1:Y_","_X1) .IF '(H<0) FOR J=+$EXTRACT(X1,1,(H-1)):1:+$EXTRACT(X1,(H+1),$LENGTH(X1)) SET Y=$SELECT($LENGTH(Y)=0:J,1:Y_","_J) KILL I,J,X1,H QUIT Y</lang>
- Example:
USER>SET U="-6,-3--1,3-5,7-11,14,15,17-20" USER>WRITE $$RANGEXP^ROSETTA(U) -6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
NetRexx
Translation of: Rexx Version 2 <lang NetRexx>/*NetRexx program to expand a range of integers into a list. *************
- 09.08.2012 Walter Pachl derived from my Rexx version
- Changes: translate(old,' ',',') -> old.translate(' ',',')
- dashpos=pos('-',x,2) -> dashpos=x.pos('-',2)
- Do -> Loop
- Parse Var a x a -> Parse a x a
- Parse Var x ... -> Parse x ...
- /
parse arg old if old = then
old='-6,-3--1,3-5,7-11,14,15,17-20' /*original list of nums/ranges */
Say 'old='old /*show old list of nums/ranges. */
a=old.translate(' ',',') /*translate commas to blanks */
new= /*new list of numbers (so far). */
comma=
Loop While a<> /* as long as there is input */
Parse a x a /* get one element */
dashpos=x.pos('-',2) /* find position of dash, if any */
If dashpos>0 Then Do /* element is low-high */
Parse x low =(dashpos) +1 high /* split the element */
Loop j=low To high /* output all numbers in range */
new=new||comma||j /* with separating commas */
comma=',' /* from now on use comma */
End
End
Else Do /* element is a number */
new=new||comma||x /* append (with comma) */
comma=',' /* from now on use comma */
End
End
Say 'new='new /*show the expanded list */
</lang> Output:
old=-6,-3--1,3-5,7-11,14,15,17-20 new=-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
Oberon-2
Oxford Oberon-2 <lang oberon2> MODULE LIVector; IMPORT SYSTEM; TYPE LIPool = POINTER TO ARRAY OF LONGINT; LIVector*= POINTER TO LIVectorDesc; LIVectorDesc = RECORD cap-: INTEGER; len-: INTEGER; LIPool: LIPool; END;
PROCEDURE (v: LIVector) Init*(cap: INTEGER); BEGIN v.cap := cap; v.len := 0; NEW(v.LIPool,cap); END Init;
PROCEDURE (v: LIVector) Add*(x: LONGINT); VAR newLIPool: LIPool; BEGIN IF v.len = LEN(v.LIPool^) THEN (* run out of space *) v.cap := v.cap + (v.cap DIV 2); NEW(newLIPool,v.cap); SYSTEM.MOVE(SYSTEM.ADR(v.LIPool^),SYSTEM.ADR(newLIPool^),v.cap * SIZE(LONGINT)); v.LIPool := newLIPool END; v.LIPool[v.len] := x; INC(v.len) END Add;
PROCEDURE (v: LIVector) At*(idx: INTEGER): LONGINT; BEGIN RETURN v.LIPool[idx]; END At; END LIVector.
MODULE LIRange; IMPORT Out, LIV := LIVector;
TYPE Range* = POINTER TO RangeDesc; RangeDesc = RECORD l,r: POINTER TO ARRAY 1 OF LONGINT; END;
PROCEDURE (r: Range) Init*(); BEGIN r.l := NIL; r.r := NIL; END Init;
PROCEDURE (r: Range) IsEmpty*(): BOOLEAN; BEGIN RETURN (r.l = NIL) & (r.l = NIL); END IsEmpty;
PROCEDURE (r: Range) SetLeft*(v: LONGINT); BEGIN IF r.l = NIL THEN NEW(r.l) END; r.l[0] := v; END SetLeft;
PROCEDURE (r: Range) SetRight*(v : LONGINT); BEGIN IF r.r = NIL THEN NEW(r.r) END; r.r[0] := v; END SetRight;
PROCEDURE (r: Range) LeftPart*(): BOOLEAN; BEGIN RETURN r.l # NIL; END LeftPart;
PROCEDURE (r: Range) GetLeft(): LONGINT; BEGIN RETURN r.l[0]; END GetLeft;
PROCEDURE (r: Range) RightPart*(): BOOLEAN; BEGIN RETURN r.l # NIL; END RightPart;
PROCEDURE (r: Range) GetRight*(): LONGINT; BEGIN RETURN r.r[0]; END GetRight;
PROCEDURE (r: Range) Show*(); BEGIN Out.Char('('); IF r.l # NIL THEN Out.LongInt(r.l[0],10) END; Out.String(" - "); IF r.r # NIL THEN Out.LongInt(r.r[0],10); END; Out.Char(')');Out.Ln END Show;
PROCEDURE (r: Range) Expand*(VAR liv: LIV.LIVector); VAR from, to : LONGINT; BEGIN IF r.l # NIL THEN from := r.l[0] ELSE from := 0 END; IF r.r # NIL THEN to := r.r[0] ELSE to := from END; WHILE (from <= to) DO liv.Add(from);INC(from) END END Expand; END LIRange.
MODULE Splitter; TYPE Splitter* = POINTER TO SplitterDesc; SplitterDesc = RECORD from: INTEGER; c: CHAR; s: POINTER TO ARRAY OF CHAR; END;
PROCEDURE (s: Splitter) Init*; BEGIN s.c := ','; s.from := 0; s.s := NIL; END Init;
PROCEDURE (s: Splitter) On*(str: ARRAY OF CHAR); BEGIN s.from := 0; NEW(s.s,LEN(str)); COPY(str,s.s^) END On;
PROCEDURE (s: Splitter) OnWithChar*(str: ARRAY OF CHAR;c: CHAR); BEGIN s.from := 0; s.c := c; NEW(s.s,LEN(str)); COPY(str,s.s^) END OnWithChar;
PROCEDURE (s: Splitter) Next*(VAR str: ARRAY OF CHAR); VAR k : INTEGER; BEGIN k := 0; IF (s.from < LEN(s.s^) - 1) & (s.s[s.from] = 0X) THEN str[0] := 0X END; WHILE (k < LEN(str) - 1) & (s.from < LEN(s.s^) - 1) & (s.s[s.from] # s.c) DO str[k] := s.s[s.from]; INC(k);INC(s.from) END; IF k < LEN(str) - 1 THEN str[k] := 0X ELSE str[LEN(str) - 1] := 0X END; WHILE (s.from < LEN(s.s^) - 1) & (s.s[s.from] # s.c) DO INC(s.from) END; INC(s.from) END Next; END Splitter.
MODULE ExpandRange; IMPORT Out, LIV := LIVector, LIR := LIRange, S := Splitter;
PROCEDURE GetNumberFrom(s: ARRAY OF CHAR; VAR from: INTEGER; VAR done: BOOLEAN): LONGINT; VAR d,i: INTEGER; num,sign: LONGINT; BEGIN i := from; num := 0;sign := 1; CASE s[i] OF '-': sign := -1;INC(i) |'+': INC(i); ELSE END; WHILE (i < LEN(s) - 1) & (s[i] >= '0') & (s[i] <= '9') DO d := ORD(s[i]) - ORD('0'); num := d + num * 10; INC(i); END; IF i = from THEN done := FALSE ELSE done := TRUE; from := i END; RETURN sign * num END GetNumberFrom;
PROCEDURE GetRange(s: ARRAY OF CHAR): LIR.Range; VAR r: LIR.Range; i: INTEGER; num: LONGINT; done: BOOLEAN; BEGIN i := 0;NEW(r);r.Init(); WHILE (i < LEN(s) - 1) & (s[i] = 20X) DO INC(i) END; (* Left value *) done := FALSE; num := GetNumberFrom(s,i,done); IF ~done THEN RETURN r END; r.SetLeft(num);
WHILE (i < LEN(s) - 1) & (s[i] = 20X) DO INC(i) END; CASE s[i] OF '-' : INC(i); | 0X : RETURN r; ELSE END; WHILE (i < LEN(s) - 1) & (s[i] = 20X) DO INC(i) END;
(* Right Value *) done := FALSE; num := GetNumberFrom(s,i,done); IF ~done THEN RETURN r END; r.SetRight(num); RETURN r; END GetRange;
VAR i: INTEGER; r: LIR.Range; sp: S.Splitter; p : ARRAY 128 OF CHAR; liv: LIV.LIVector; BEGIN NEW(sp);sp.Init(); NEW(liv);liv.Init(128);
sp.On("-6,-3--1,3-5,7-11,14,15,17-20"); sp.Next(p); WHILE (p[0] # 0X) DO r := GetRange(p); r.Expand(liv); sp.Next(p); END; FOR i := 0 TO liv.len - 2 DO Out.LongInt(liv.At(i),3);Out.Char(','); END; Out.LongInt(liv.At(liv.len - 1),3);Out.Ln; END ExpandRange.
</lang> Output:
-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
OCaml
<lang ocaml>#load "str.cma"
let range a b =
if b < a then invalid_arg "range"; let rec aux i acc = if i = b then List.rev(i::acc) else aux (succ i) (i::acc) in aux a []
let parse_piece s =
try Scanf.sscanf s "%d-%d" (fun a b -> range a b) with _ -> [int_of_string s]
let range_expand rng =
let ps = Str.split (Str.regexp_string ",") rng in List.flatten (List.map parse_piece ps)
let () =
let rng = "-6,-3--1,3-5,7-11,14,15,17-20" in let exp = range_expand rng in List.iter (Printf.printf " %d") exp; print_newline()</lang>
ooRexx
<lang ooRexx> list = '-6,-3--1,3-5,7-11,14,15,17-20' expanded = expandRanges(list)
say "Original list: ["list"]" say "Expanded list: ["expanded~tostring("l", ",")"]"
-- expand a string expression a range of numbers into a list -- of values for the range. This returns an array
- routine expandRanges
use strict arg list
values = list~makearray(',')
-- build this up using an array first. Make this at least the
-- size of the original value set.
expanded = .array~new(values~items)
-- now process each element in the range
loop element over values
-- if this is a valid number, it's not a range, so add it directly
if element~datatype('whole') then expanded~append(element)
else do
-- search for the divider, starting from the second position
-- to allow for the starting value to be a minus sign.
split = element~pos('-', 2)
parse var element start =(split) +1 finish
loop i = start to finish
expanded~append(i)
end
end
end
return expanded
</lang> Output:
Original list: [-6,-3--1,3-5,7-11,14,15,17-20] Expanded list: [-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20]
Oz
<lang oz>declare
fun {Expand RangeDesc}
{Flatten
{Map {ParseDesc RangeDesc}
ExpandRange}}
end
fun {ParseDesc Txt}
{Map {String.tokens Txt &,} ParseRange}
end
fun {ParseRange R}
if {Member &- R.2} then
First Second
in
{String.token R.2 &- ?First ?Second}
{String.toInt R.1|First}#{String.toInt Second}
else
Singleton = {String.toInt R}
in
Singleton#Singleton
end
end
fun {ExpandRange From#To}
{List.number From To 1}
end
in
{System.showInfo
{Value.toVirtualString {Expand "-6,-3--1,3-5,7-11,14,15,17-20"} 100 100}}</lang>
- Sample output:
<lang oz>[~6 ~3 ~2 ~1 3 4 5 7 8 9 10 11 14 15 17 18 19 20]</lang>
Perl
One-liner: <lang Perl>sub rangex {
map { /^(.*\d)-(.+)$/ ? $1..$2 : $_ } split /,/, shift
}
- Test and display
print join(',', rangex('-6,-3--1,3-5,7-11,14,15,17-20')), "\n";</lang>
- Output:
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
Alternative: <lang Perl>sub rangex {
(my $range = shift) =~ s/(?<=\d)-/../g; eval $range;
}</lang>
Perl 6
<lang Perl6>sub range-expansion (Str $range-description) {
my $range-pattern = rx/ ( '-'? \d+ ) '-' ( '-'? \d+) /;
my &expand = -> $term { $term ~~ $range-pattern ?? +$0..+$1 !! $term };
return $range-description.split(',').map(&expand)
}
say range-expansion('-6,-3--1,3-5,7-11,14,15,17-20').join(', ');</lang>
- Output:
-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
PHP
<lang PHP>function rangex($str) {
$lst = array();
foreach (explode(',', $str) as $e) {
if (strpos($e, '-', 1) !== FALSE) {
list($a, $b) = explode('-', substr($e, 1), 2);
$lst = array_merge($lst, range($e[0] . $a, $b));
} else {
$lst[] = (int) $e;
}
}
return $lst;
}</lang>
PicoLisp
<lang PicoLisp>(de rangeexpand (Str)
(make
(for S (split (chop Str) ",")
(if (index "-" (cdr S))
(chain
(range
(format (head @ S))
(format (tail (- -1 @) S)) ) )
(link (format S)) ) ) ) )</lang>
- Output:
: (rangeexpand "-6,-3--1,3-5,7-11,14,15,17-20") -> (-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20)
PL/I
<lang PL/I>range_expansion:
procedure options (main);
get_number:
procedure (Number, c, eof); declare number fixed binary (31), c character (1), eof bit (1) aligned; declare neg fixed binary (1);
number = 0; eof = false;
do until (c ^= ' ');
get edit (c) (a(1));
end;
if c = '-' then do; get edit (c) (a(1)); neg = -1; end; else neg = 1;
do forever;
select (c);
when ('0', '1', '2', '3', '4', '5', '6', '7', '8', '9')
number = number*10 + c;
when (',', '-') do; number = neg*number; return; end;
otherwise signal error;
end;
on endfile (sysin) go to exit;
get edit (c) (a(1));
end;
exit:
number = neg*number; eof = true;
end get_Number;
declare c character, (i, range_start, range_end) fixed binary (31);
declare eof bit (1) aligned;
declare true bit (1) value ('1'b), false bit (1) value ('0'b);
declare delimiter character (1) initial (' ');
declare out file output;
open file (out) output title ('/out, type(text),recsize(80)');
do while (^eof);
call get_number(range_start, c, eof);
if c = '-' then /* we have a range */
do;
call get_number (range_end, c, eof);
do i = range_start to range_end;
put file (out) edit (delimiter, i) (a, f(3));
end;
end;
else
do;
put file (out) edit (delimiter, range_start) (a, f(3));
end;
delimiter = ',';
end;
end range_expansion;</lang>
- Output:
-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
Prolog
The code uses three predicates extract_Range/2, study_Range/2 and pack_Range/2.
Every predicate works in both directions arg1 towards arg2 and arg2 towards arg1, so that Range expansion and Range extraction work with the same predicates but in reverse order.
<lang Prolog>range_expand :-
L = '-6,-3--1,3-5,7-11,14,15,17-20',
writeln(L),
atom_chars(L, LA),
extract_Range(LA, R),
maplist(study_Range, R, LR),
pack_Range(LX, LR),
writeln(LX).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % extract_Range(?In, ?Out) % In : '-6,-3--1,3-5,7-11,14,15,17-20' % Out : [-6], [-3--1], [3-5],[7-11], [14],[15], [17-20] % extract_Range([], []).
extract_Range(X , [Range | Y1]) :- get_Range(X, U-U, Range, X1), extract_Range(X1, Y1).
get_Range([], Range-[], Range, []). get_Range([','|B], Range-[], Range, B) :- !.
get_Range([A | B], EC, Range, R) :- append_dl(EC, [A | U]-U, NEC), get_Range(B, NEC, Range, R).
append_dl(X-Y, Y-Z, X-Z).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % study Range(?In, ?Out) % In : [-6] % Out : [-6,-6] % % In : [-3--1] % Out : [-3, -1] % study_Range(Range1, [Deb, Deb]) :-
catch(number_chars(Deb, Range1), Deb, false).
study_Range(Range1, [Deb, Fin]) :-
append(A, ['-'|B], Range1),
A \= [],
number_chars(Deb, A),
number_chars(Fin, B).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
- - use_module(library(clpfd)).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % Pack Range(?In, ?Out) % In : -6, % Out : [-6] % % In : -3, -2,-1 % Out : [-3,-1] % pack_Range([],[]).
pack_Range([X|Rest],[[X | V]|Packed]):-
run(X,Rest, [X|V], RRest), pack_Range(RRest,Packed).
run(Fin,[Other|RRest], [Deb, Fin],[Other|RRest]):-
Fin #\= Deb,
Fin #\= Deb + 1,
Other #\= Fin+1.
run(Fin,[],[_Var, Fin],[]).
run(Var,[Var1|LRest],[Deb, Fin], RRest):- Fin #\= Deb, Fin #\= Deb + 1, Var1 #= Var + 1, run(Var1,LRest,[Deb, Fin], RRest).
run(Val,[Other|RRest], [Val, Val],[Other|RRest]).</lang>
- Output:
?- range_expand. -6,-3--1,3-5,7-11,14,15,17-20 [-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20] true
PureBasic
<lang PureBasic>Procedure rangeexpand(txt.s, List outputList())
Protected rangesCount = CountString(txt, ",") + 1
Protected subTxt.s, r, rangeMarker, rangeStart, rangeFinish, rangeIncrement, i
LastElement(outputList())
For r = 1 To rangesCount
subTxt = StringField(txt, r, ",")
rangeMarker = FindString(subTxt, "-", 2)
If rangeMarker
rangeStart = Val(Mid(subTxt, 1, rangeMarker - 1))
rangeFinish = Val(Mid(subTxt, rangeMarker + 1))
If rangeStart > rangeFinish
rangeIncrement = -1
Else
rangeIncrement = 1
EndIf
i = rangeStart - rangeIncrement
Repeat
i + rangeIncrement
AddElement(outputList()): outputList() = i
Until i = rangeFinish
Else
AddElement(outputList()): outputList() = Val(subTxt)
EndIf
Next
EndProcedure
Procedure outputListValues(List values())
Print("[ ")
ForEach values()
Print(Str(values()) + " ")
Next
PrintN("]")
EndProcedure
If OpenConsole()
NewList values()
rangeexpand("-6,-3--1,3-5,7-11,14,15,17-20", values())
outputListValues(values())
Print(#CRLF$ + #CRLF$ + "Press ENTER to exit")
Input()
CloseConsole()
EndIf</lang>
- Output:
[ -6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20 ]
Python
<lang python>def rangeexpand(txt):
lst = []
for r in txt.split(','):
if '-' in r[1:]:
r0, r1 = r[1:].split('-', 1)
lst += range(int(r[0] + r0), int(r1) + 1)
else:
lst.append(int(r))
return lst
print(rangeexpand('-6,-3--1,3-5,7-11,14,15,17-20'))</lang> Another variant, using regular expressions to parse the ranges: <lang python>import re
def rangeexpand(txt):
lst = []
for rng in txt.split(','):
start,end = re.match('^(-?\d+)(?:-(-?\d+))?$', rng).groups()
if end:
lst.extend(xrange(int(start),int(end)+1))
else:
lst.append(int(start))
return lst</lang>
- Output:
[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]
R
A function to do the range expansion: <lang R> rangeExpand <- function(text) { x <- unlist(strsplit(text, ",")) # split the string on commas x <- gsub("(\\d)-", "\\1:", x) # substitute dashes following a digit with a colon lst <- list(mode = "list", length = length(x)) # an empty list to hold evaluated elements for (i in 1:length(x)) { # evaluate each element and add to the list lsti <- eval(parse(text = x[i])) } unlist(lst, use.names = FALSE) # return the expanded integers } </lang> Now test it: <lang R> rangeExpand("-6,-3--1,3-5,7-11,14,15,17-20")
[1] -6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20
</lang>
Racket
<lang racket>
- lang racket
(define (range-expand s)
(append*
(for/list ([r (regexp-split "," s)])
(match (regexp-match* "(-?[0-9]+)-(-?[0-9]+)" r
#:match-select cdr)
[(list (list f t))
(range (string->number f) (+ (string->number t) 1))]
[(list)
(list (string->number r))]))))
(range-expand "-6,-3--1,3-5,7-11,14,15,17-20") </lang> Output:
'(-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20)
Here is an alternative version without regular expressions. It uses the builtin function read to read the numbers.
Since 3--4 is normally parsed as a symbol rather than 3 followed by - followed by -4, a readtable is
installed that makes - a delimiter.
<lang racket>
- lang racket
(define on-minus
(case-lambda
[(ch ip) (on-minus ch ip #f #f #f #f)]
[(ch ip src line col pos)
(if (char-numeric? (peek-char ip))
(- (read ip))
(datum->syntax #f '-))]))
(define minus-delimits
(make-readtable (current-readtable) #\- 'terminating-macro on-minus))
(define (range-expand s)
(parameterize ([current-readtable minus-delimits])
(append*
(for/list ([f (in-port read s)])
(match (peek-char s)
[#\, (read-char s)
(list f)]
[#\- (read-char s)
(define t (read s))
(read-char s)
(range f (+ t 1))])))))
(range-expand (open-input-string "-6,-3--1,3-5,7-11,14,15,17-20")) </lang> Note that one can use the full number syntax in this alternative version:
> (range-expand (open-input-string "1-6/3,3e1-32")) '(1 2 30.0 31.0 32.0)
Raven
Based loosely on Ruby <lang raven>define get_num use $lst
# "-22" split by "-" is [ "", "22" ] so check if
# first list item is "" -> a negative number
$lst 0 get "" = if
# negative number
#
# convert str to integer and multiply by -1
-1 $lst 1 get 0 prefer *
$lst shift $lst shift drop drop
else
# positive number
$lst 0 get 0 prefer
$lst shift drop
define range_expand use $rng
[ ] as $res
$rng "," split each as $r
$r m/^(-?\d+)-(-?\d+)$/ TRUE = if
$r s/-/g as $parts
$parts get_num as $from
$parts get_num as $to
# int list to str list, then joined by ","
group
$from $to 1 range each "" prefer
list "," join $res push
# range doesn't include the $to, so add to end of generated range
$to "%d" $res push
else
$r $res push
$res "," join print
"\n" print
'-6,-3--1,3-5,7-11,14,15,17-20' range_expand</lang>
- Output:
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
REXX
version 1
Extra blanks were added to the original list (which are ignored) to make an over/under comparison easier. <lang rexx>/*REXX program expands an ordered list of integers into an expanded list*/ old='-6,-3--1, 3-5, 7-11,14,15, 17-20'; a=translate(old,,',') new= /*change , ──► blanks [↑] */
do until a==; parse var a X a /*obtain the next integer|range. */
p=pos('-',X,2) /*find location of a dash (maybe)*/
if p==0 then new=new X /*append X to the new list. */
else do j=left(X,p-1) to substr(X,p+1) /*Range? Build it*/
new=new j /*append single integer at a time*/
end /*j*/
end /*until*/
new=translate( strip(new), ',' ," ") /*remove first blank, add commas.*/ say 'old list =' old /*show old list of numbers/ranges*/ say 'new list =' new /*show the new list of numbers.*/
/*stick a fork in it, we're done.*/</lang>
output
old list = -6,-3--1, 3-5, 7-11,14,15, 17-20 new list = -6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
Version 2 somewhat simplified !?!
<lang rexx>/*REXX program to expand a range of integers into a list. *************
- 09.08.2012 Walter Pachl
- /
parse arg old if old = then - old='-6,-3--1,3-5,7-11,14,15,17-20' /*original list of nums/ranges */
Say 'old='old /*show old list of nums/ranges. */ a=translate(old,,',') /*translate commas to blanks */ new= /*new list of numbers (so far). */
comma=
Do While a<> /* as long as there is input */
Parse var a x a /* get one element */
dashpos=pos('-',x,2) /* find position of dash, if any */
If dashpos>0 Then Do /* element is low-high */
Parse Var x low =(dashpos) +1 high /* split the element */
Do j=low To high /* output all numbers in range */
new=new||comma||j /* with separating commas */
comma=',' /* from now on use comma */
End
End
Else Do /* element is a number */
new=new||comma||x /* append (with comma) */
comma=',' /* from now on use comma */
End
End
Say 'new='new /*show the expanded list */</lang>
Output:
old=-6,-3--1,3-5,7-11,14,15,17-20 new=-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
Ruby
<lang ruby>def range_expand(rng)
rng.split(',').collect do |part|
if part =~ /^(-?\d+)-(-?\d+)$/
($1.to_i .. $2.to_i).to_a
else
Integer(part)
end
end.flatten
end
p range_expand('-6,-3--1,3-5,7-11,14,15,17-20')</lang>
- Output:
[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]
Run BASIC
<lang runbasic>PRINT rangeExpand$("-6,-3--1,3-5,7-11,14,15,17-20") end
function rangeExpand$(range$) [loop] i = INSTR(range$, "-", i+1) IF i THEN
j = i
WHILE MID$(range$,j-1,1) <> "," AND j <> 1
j = j - 1
wend
IF i > j then
IF MID$(range$,j,i-j) <> str$(i-j)+" " THEN
t$ = ""
FOR k = VAL(MID$(range$,j)) TO VAL(MID$(range$,i+1))-1
t$ = t$ + str$(k) + ","
NEXT k
range$ = LEFT$(range$,j-1) + t$ + MID$(range$,i+1)
i = j + LEN(t$) + 2
end if
end if
end if if i <> 0 then goto [loop] rangeExpand$ = range$ end function</lang>
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
Scala
<lang ruby>def rangex(str: String): Seq[Int] =
str split "," flatMap { (s) =>
val r = """(-?\d+)(?:-(-?\d+))?""".r
val r(a,b) = s
if (b == null) Seq(a.toInt) else a.toInt to b.toInt
}</lang>
Scheme
<lang scheme>(define split
(lambda (str char skip count)
(let ((len (string-length str)))
(let loop ((index skip)
(last-index 0)
(result '()))
(if (= index len)
(reverse (cons (substring str last-index) result))
(if (eq? char (string-ref str index))
(loop (if (= count (+ 2 (length result)))
len
(+ index 1))
(+ index 1)
(cons char (cons (substring str last-index index)
result)))
(loop (+ index 1)
last-index
result)))))))
(define range-expand
(lambda (str)
(for-each
(lambda (token)
(if (char? token)
(display token)
(let ((range (split token #\- 1 2)))
(if (null? (cdr range))
(display (car range))
(do ((count (string->number (list-ref range 0)) (+ 1 count))
(high (string->number (list-ref range 2))))
((= count high) (display high))
(display count)
(display ","))))))
(split str #\, 0 0))
(newline)))</lang>
- Output:
(range-expand "-6,-3--1,3-5,7-11,14,15,17-20") -6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
Seed7
The library scanstri.s7i defines the function getInteger to extract substrings with integer literals (optional sign followed by a sequence of digits) from a string. The integer literals are converted to the type integer with the parse operator. <lang seed7>$ include "seed7_05.s7i";
include "scanstri.s7i";
const func array integer: rangeExpansion (in var string: rangeStri) is func
result
var array integer: numbers is 0 times 0;
local
var integer: number is 0;
begin
while rangeStri <> "" do
number := integer parse getInteger(rangeStri);
numbers &:= number;
if startsWith(rangeStri, "-") then
rangeStri := rangeStri[2 ..];
for number range succ(number) to integer parse getInteger(rangeStri) do
numbers &:= number;
end for;
end if;
if startsWith(rangeStri, ",") then
rangeStri := rangeStri[2 ..];
elsif rangeStri <> "" then
raise RANGE_ERROR;
end if;
end while;
end func;
const proc: main is func
local
var integer: number is 0;
begin
for number range rangeExpansion("-6,-3--1,3-5,7-11,14,15,17-20") do
write(number <& " ");
end for;
writeln;
end func;</lang>
- Output:
-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20
SNOBOL4
<lang SNOBOL4>* # Return range n1 .. n2
define('range(n1,n2)') :(range_end)
range range = range n1 ','; n1 = lt(n1,n2) n1 + 1 :s(range)
range rtab(1) . range :(return)
range_end
define('rangex(range)d1,d2')
num = ('-' | ) span('0123456789') :(rangex_end)
rangex range num . d1 '-' num . d2 = range(d1,d2) :s(rangex)
rangex = range :(return)
rangex_end
- # Test and display
output = rangex('-6,-3--1,3-5,7-11,14,15,17-20')
end</lang>
- Output:
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
Tcl
<lang tcl>proc rangeExpand desc {
set result {}
foreach term [split $desc ","] {
set count [scan $term %d-%d from to] if {$count == 1} { lappend result $from } elseif {$count == 2} { for {set i $from} {$i <= $to} {incr i} {lappend result $i} }
} return $result
}
puts [rangeExpand "-6,-3--1,3-5,7-11,14,15,17-20"]</lang>
- Output:
-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20
TUSCRIPT
<lang tuscript>$$ MODE TUSCRIPT rangednrs="-6,-3--1,3-5,7-11,14,15,17-20" expandnrs=SPLIT (rangednrs,":,:")
LOOP/CLEAR r=expandnrs
test=STRINGS (r,":><-><<>>/:") sz_test=SIZE (test) IF (sz_test==1) THEN expandnrs=APPEND (expandnrs,r) ELSE r=SPLIT (r,"::<|->/::-:",beg,end) expandnrs=APPEND (expandnrs,beg) LOOP/CLEAR next=beg,end next=next+1 expandnrs=APPEND (expandnrs,next) IF (next==end) EXIT ENDLOOP ENDIF
ENDLOOP expandnrs= JOIN (expandnrs,",")
PRINT expandnrs</lang>
- Output:
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
TXR
A solution with three main parts:
- a parse-expression-grammar driven parser to decimate the input to a Lisp data structure;
- some Lisp code to expand the list, sort it, and remove duplicates (recursion, hashing, sorting).
- driver code which matches the input with the grammar, and produces output with the help of the Lisp code.
The grammar is:
num := [ + | - ] { digit } +
entry := num [ ws ] - [ ws ] num
| num
rangelist := entry [ ws ] , [ ws ] rangelist
| entry
| /* empty */Code:
<lang txr>@(define num (n))@(local tok)@{tok /[+\-]?\d+/}@(bind n @(int-str tok))@(end) @(define entry (e))@\
@(local n1 n2)@\ @(cases)@\ @(num n1)@/\s*-\s*/@(num n2)@\ @(bind e (n1 n2))@\ @(or)@\ @(num n1)@\ @(bind e n1)@\ @(end)@\
@(end) @(define rangelist (list))@\
@(local first rest)@\ @(cases)@\ @(entry first)@/\s*,\s*/@(rangelist rest)@\ @(bind list @(cons first rest))@\ @(or)@\ @(entry first)@\ @(bind list (first))@\ @(or)@\ @(bind list nil)@\ @(end)@\
@(end) @(do
(defun expand-helper (list)
(cond
((null list) nil)
((consp (first list))
(append (range (first (first list))
(second (first list)))
(rangeexpand (rest list))))
(t (cons (first list) (rangeexpand (rest list))))))
(defun sortdup (li)
(let ((h (hash-construct nil [mapcar list li])))
[sort (hash-keys h) <]))
(defun rangeexpand (list)
(sortdup (expand-helper list))))
@(repeat) @(rangelist x)@{trailing-junk} @(output) raw syntax: @x expansion: @(rangeexpand x) your junk: @{trailing-junk} @(end) @(end)</lang>
Run:
$ txr range-expansion.txr - 1,2,3-5,-3--1 raw syntax: 1 2 (3 5) (-3 -1) expansion: (-3 -2 -1 1 2 3 4 5) your junk: -6,-3--1,3-5,7-11,14,15,17-20 raw syntax: -6 (-3 -1) (3 5) (7 11) 14 15 (17 20) expansion: (-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20) your junk: -6,-3--1,3-5,7-11,14,15,17-20,cg@foo raw syntax: -6 (-3 -1) (3 5) (7 11) 14 15 (17 20) expansion: (-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20) your junk: cg@foo
Note how the junk in the last example does not contain the trailing comma. This is because the rangelist grammar production allows for an empty range, so syntax like "5," is valid: it's an entry followed by a comma and a rangelist, where the rangelist is empty.
UNIX Shell
<lang bash>#!/usr/bin/bash
range_expand () (
IFS=,
set -- $1
n=$#
for element; do
if [[ $element =~ ^(-?[0-9]+)-(-?[0-9]+)$ ]]; then
set -- "$@" $(eval echo "{${BASH_REMATCH[1]}..${BASH_REMATCH[2]}}")
else
set -- "$@" $element
fi
done
shift $n
echo "$@"
# to return a comma-separated value: echo "${*// /,}"
)
range_expand "-6,-3--1,3-5,7-11,14,15,17-20"</lang>
- Output:
-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20
Ursala
<lang Ursala>#import std
- import int
rex = sep`,; zrange+*= %zp~~htttPzztPQhQXbiNC+ rlc ~&r~=`-
- cast %zL
t = rex '-6,-3--1,3-5,7-11,14,15,17-20'</lang>
- Output:
<-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20>
VBA
<lang VBA>Public Function RangeExpand(AString as string) ' return a list with the numbers expressed in AString Dim Splits() As String Dim List() As Integer Dim count As Integer
count = -1 'to start a zero-based List() array ' first split it using comma as delimiter Splits = Split(AString, ",") ' process all fragments For Each fragment In Splits
'is there a "-" in it (do not consider first character)?
P = InStr(2, fragment, "-")
If P > 0 Then 'yes, so it's a range: find start and end numbers
nstart = Val(left$(fragment, P - 1))
nend = Val(Mid$(fragment, P + 1))
j = count
count = count + (nend - nstart + 1)
'add numbers in range to List
ReDim Preserve List(count)
For i = nstart To nend
j = j + 1
List(j) = i
Next
Else
'not a range, add a single number
count = count + 1
ReDim Preserve List(count)
List(count) = Val(fragment)
End If
Next RangeExpand = List End Function
Public Sub RangeExpandTest() 'test function RangeExpand Dim X As Variant
X = RangeExpand("-6,-3--1,3-5,7-11,14,15,17-20") 'print X Debug.Print "Result:" For Each el In X
Debug.Print el;
Next Debug.Print End Sub</lang>
- Output:
RangeExpandTest Result: -6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20
XPL0
<lang XPL0>include c:\cxpl\codes; \intrinsic 'code' declarations string 0; \use zero-terminated strings, instead of MSb char Str; int Char, Inx;
proc GetCh; \Get character from Str
[Char:= Str(Inx);
Inx:= Inx+1;
]; \GetCh
func GetNum; \Get number from Str and return its value
int Neg, Num;
[Neg:= false;
if Char = ^- then [Neg:= true; GetCh];
Num:= 0;
while Char>=^0 & Char<=^9 do
[Num:= Num*10 + Char-^0;
GetCh;
];
return if Neg then -Num else Num; ]; \GetNum
int I, N0, N1;
[Str:= "-6,-3--1,3-5,7-11,14,15,17-20";
Inx:= 0;
GetCh; \one character look ahead
loop [N0:= GetNum;
IntOut(0,N0);
case Char of
^,: [GetCh; ChOut(0,^,)];
^-: [GetCh;
N1:= GetNum;
for I:= N0+1 to N1 do \expand range
[ChOut(0,^,); IntOut(0,I)];
if Char=^, then [GetCh; ChOut(0,^,)] else quit]
other quit; \must be 0 string terminator
];
CrLf(0); ]</lang>
Output:
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
- Programming Tasks
- Solutions by Programming Task
- Ada
- ALGOL 68
- AutoHotkey
- AWK
- BBC BASIC
- Bracmat
- C
- C sharp
- C++
- Clojure
- Common Lisp
- D
- Erlang
- Forth
- F Sharp
- Go
- Groovy
- Haskell
- Icon
- Unicon
- J
- Java
- JavaScript
- Julia
- K
- Lasso
- Liberty BASIC
- Maple
- Mathematica
- MATLAB
- Octave
- MUMPS
- NetRexx
- Oberon-2
- OCaml
- OoRexx
- Oz
- Perl
- Perl 6
- PHP
- PicoLisp
- PL/I
- Prolog
- Clpfd
- PureBasic
- Python
- R
- Racket
- Raven
- REXX
- Ruby
- Run BASIC
- Scala
- Scheme
- Seed7
- SNOBOL4
- Tcl
- TUSCRIPT
- TXR
- UNIX Shell
- Ursala
- VBA
- XPL0