Range expansion
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)
You are encouraged to solve this task according to the task description, using any language you may know.
- 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> Sample 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))
)</lang> Output:
-6 -3 -2 -1 +3 +4 +5 +7 +8 +9 +10 +11 +14 +15 +17 +18 +19 +20
C
<lang c>#include <stdio.h>
- include <stdlib.h>
- include <string.h>
- include <stdarg.h>
- include <stdbool.h>
enum range_action { RANGE_NEW, RANGE_NEXT, RANGE_RESET, RANGE_FREE };
typedef struct range_s {
long int val; char *range; // private members size_t pos; size_t slen; long int clower; long int cupper; bool inrange;
} *range_t;
range_t range(enum range_action action, ...) {
range_t r; va_list al; char *ep, *tp;
va_start(al, action);
switch(action) {
case RANGE_NEW:
r = malloc(sizeof(struct range_s));
if (r != NULL) {
r->range = va_arg(al, char *);
r->pos = 0;
r->slen = strlen(r->range);
r->inrange = false;
}
break;
case RANGE_NEXT:
r = va_arg(al, range_t);
if ( r->inrange ) {
if ( r->val < r->cupper ) {
r->val++; va_end(al); return r;
} else {
r->inrange = false;
}
}
if ( r->pos >= r->slen ) return NULL;
r->val = strtol(r->range + r->pos, &ep, 10);
if ( ep == (r->range + r->pos) ) return NULL;
if ( *ep == '-' ) {
r->clower = r->val;
r->cupper = strtol(ep + 1, &tp, 10);
if ( (ep+1) == tp ) return NULL;
r->inrange = true;
ep = tp;
} // any other symbol works like ,
r->pos = ep+1 - r->range;
break;
case RANGE_RESET:
r = va_arg(al, range_t);
r->pos = 0;
break;
case RANGE_FREE:
r = va_arg(al, range_t);
free(r);
return NULL;
}
va_end(al);
return r;
}
// usage int main() {
range_t r = range(RANGE_NEW, "-6,-3--1,3-5,7-11,14,15,17-20");
while( range(RANGE_NEXT, r) != NULL )
{
printf("%d ", r->val);
}
printf("\n");
range(RANGE_FREE, r);
return 0;
}</lang>
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.Length == 2)
{
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>
D
Compiled with D V.2.048. From the second Python version. <lang d>import std.stdio, std.regex, std.string, std.conv, std.range;
int[] rangeExpand(string txt) {
int[] result;
foreach (r; txt.split(",")) {
auto m = array(match(r, regex(r"^(-?\d+)(-?(-?\d+))?$")).captures);
if (m.length > 2)
result ~= array(iota(to!int(m[1]), to!int(m[3])+1));
else
result ~= to!int(m[1]);
}
return result;
}
void main() {
writeln(rangeExpand("-6,-3--1,3-5,7-11,14,15,17-20"));
}</lang> Output:
[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]
F#
<lang fsharp>open System.Text.RegularExpressions
// simplify regex matching with an active pattern let (|Regexp|_|) pattern txt =
match Regex.Match(txt, pattern) with | m when m.Success -> [for g in m.Groups -> g.Value] |> List.tail |> Some | _ -> None
// Parse and expand a single range description. // string -> int list let parseRange r =
match r with | Regexp @"^(-?\d+)-(-?\d+)$" [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]
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>
Sample 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.)/@:(0 1 + -~/\) num=: _&". normaliz=: rplc&(',-';',_';'--';'-_')@,~&',' lumps=:<@(num`([:to num;._1@,~&'-')@.('-'&e.));._1 rngexp=: ;@lumps@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>
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;
}
if ( inrange ) 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>
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
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>
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 (in Oz list syntax): <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
Based on Python version.
<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 <lang>
-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
</lang>
Prolog
Works with SWI-Prolog and library clpfd.
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> Sample 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>
Sample output
[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]
REXX
<lang rexx> /*REXX program to expand a range of integers into a list. */
old='-6,-3--1,3-5,7-11,14,15,17-20' /*original list of nums/ranges. */
say 'old list='old /*show old list of nums/ranges. */ a=translate(old,,',') /*translate commas to blanks */ new= /*new list of numbers (so far). */
do j=1 /*process each number or range. */
y= /*nullify the output number(s). */
parse var a x a; if x== then leave /*get next num/range. Null? Done.*/
minus=pos('-',x,2) /*find location of a dash (maybe)*/
if minus\==0 then do /*if found then process range. */
do k=left(x,minus-1) to substr(x,minus+1)
y=y k /*build one integer at a time. */
end
x= /*nullify X, it's still a range. */
end
new=new x y /*append them to the new list. */
end
new=space(new) /*remove extraneous blanks. */ say 'new list='new /*show the new list of numbers. */ </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
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]
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>
(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
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