Range expansion

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).

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.

11l

Translation of: Python
`F rangeexpand(txt)   Array[Int] lst   L(r) txt.split(‘,’)      I ‘-’ C r[1..]         V rr = r[1..].split(‘-’, 2)         lst [+]= Int(r[0]‘’rr[0]) .. Int(rr[1])      E         lst.append(Int(r))   R lst print(rangeexpand(‘-6,-3--1,3-5,7-11,14,15,17-20’))`

8th

`\ Given a low and high limit, create an array containing the numbers in the\ range, inclusive:: n:gen-range \ low hi -- a  \ make sure they are in order:  2dup n:> if swap then  \ fill the array with the values:  [] ' a:push   2swap loop ; \ Take a string, either "X" or "X-Y", and correctly return either a number (if\ "X") or an array of numbers (if "X-Y"):: n:expand-one \ s -- n | a[n,..m]  \ First see if we can parse a number.  This works in the "X" case:  dup >n null? if    \ Failed >n because it's (possibly) "X-Y"    drop    \ not a valid number, might be a range    \ We'll use a capturing regex to handle the different cases correctly:    /(-?[0-9]+)-(-?[0-9]+)/ tuck r:match      \ If the regex matches three (the whole string, plus the two captured    \ expressions) then it's a valid "X-Y":    3 n:= if      1 r:@ >n swap 2 r:@ >n nip      \ generate the range:      n:gen-range    else      \ The regex didn't match, so we got garbage.  Therefore, return a 'null':      drop null    then  else    \ It was a "X", just drop the original string:    nip  then   ; \ Take an array (possibly) containing other arrays, and flatten any contained\ arrays so the result is a simple array:: a:flatten \ a1 -- a2  [] >r  (    nip    array?  if      a:flatten r> swap a:+ >r    else      r> swap a:push >r    then  ) a:each drop r> ; \ Take a comma-delimited string of ranges, and expand it into an array of\ numbers:: n:range-expand \ str -- a  "," s:/  ' n:expand-one a:map  a:flatten ; \ Process a list:"-6,-3--1,3-5,7-11,14,15,17-20" n:range-expand\ print the expanded list:. cr bye`
Output:
```[-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20]
```

The function Expand takes a string and returns a corresponding array of integers. Upon syntax errors Constraint_Error is propagated:

`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;`
Output:
```-6,-3,-2,-1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
```

Aime

 This example is incorrect. Please fix the code and remove this message.Details: Needs "a comma separated list" without the trailing comma
`list l; file().b_affix("-6,-3--1,3-5,7-11,14,15,17-20").news(l, 0, 0, ",");for (, text s in l) {    integer a, b, p;     p = b_frame(s, '-');    if (p < 1) {        o_(s, ",");    } else {        p -= s[p - 1] == '-' ? 1 : 0;        a = s.cut(0, p).atoi;        b = s.erase(0, p).atoi;        do {            o_(a, ",");        } while ((a += 1) <= b);    }} o_("\n");`

or:

`integer p;list l; file().b_affix("-6,-3--1,3-5,7-11,14,15,17-20").news(l, 0, 0, ",");for (, text s in l) {    if ((p = b_frame(s, '-')) < 1) {        o_(s, ",");    } else {        p -= s[p - 1] == '-' ? 1 : 0;        call_s(o_, 0, s.cut(0, p).atoi, s.erase(0, p).atoi + 1, 1, ",");    }} o_("\n");`
Output:
`-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20,`

ALGOL 68

Works with: ALGOL 68 version Revision 1 - no extensions to language used
Works with: ALGOL 68G version Any - tested with release 1.18.0-9h.tiny - string parsing and formatting code tested with 2.6.win32
Works with: ELLA ALGOL 68 version Any (with appropriate job cards) - tested with release 1.8-8d
`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 stringEND; # TORANGE #  # converts a []INT to a comma separated string of the elements #OP TOSTRING = ( []INT values )STRING:BEGIN     STRING result    := "";    STRING separator := "";     FOR pos FROM LWB values TO UPB values    DO        result +:= ( separator + whole( values[ pos ], 0 ) );        separator := ","    OD; # RESULT #    resultEND; # TOSTRING #  test:(    print( ( TOSTRING range expand( TORANGE "-6,-3--1,3-5,7-11,14,15,17-20" ), newline ) )) `
Output:
```-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
```

AppleScript

Translation of: JavaScript
(Functional ES5 version)
`-- Each comma-delimited string is mapped to a list of integers,-- and these integer lists are concatenated together into a single list -- expansion :: String -> [Int]on expansion(strExpr)    -- The string (between commas) is split on hyphens,     -- and this segmentation is rewritten to ranges or minus signs    -- and evaluated to lists of integer values     -- signedRange :: String -> [Int]    script signedRange        -- After the first character, numbers preceded by an        -- empty string (resulting from splitting on hyphens)        -- and interpreted as negative         -- signedIntegerAppended:: [Int] -> String -> Int -> [Int] -> [Int]        on signedIntegerAppended(lstAccumulator, strNum, iPosn, lst)            if strNum ≠ "" then                if iPosn > 1 then                    if length of (item (iPosn - 1) of lst) > 0 then                        set strSign to ""                    else                        set strSign to "-"                    end if                else                    set strSign to "+"                end if                lstAccumulator & ((strSign & strNum) as integer)            else                lstAccumulator            end if        end signedIntegerAppended         on |λ|(strHyphenated)            tupleRange(foldl(signedIntegerAppended, {}, ¬                splitOn("-", strHyphenated)))        end |λ|    end script     concatMap(signedRange, splitOn(",", strExpr))end expansion  -- TEST -----------------------------------------------------------------------on run     expansion("-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}end run  -- GENERIC FUNCTIONS ---------------------------------------------------------- -- concatMap :: (a -> [b]) -> [a] -> [b]on concatMap(f, xs)    script append        on |λ|(a, b)            a & b        end |λ|    end script     foldl(append, {}, map(f, xs))end concatMap -- enumFromTo :: Int -> Int -> [Int]on enumFromTo(m, n)    if n < m then        set d to -1    else        set d to 1    end if    set lst to {}    repeat with i from m to n by d        set end of lst to i    end repeat    return lstend enumFromTo -- foldl :: (a -> b -> a) -> a -> [b] -> aon foldl(f, startValue, xs)    tell mReturn(f)        set v to startValue        set lng to length of xs        repeat with i from 1 to lng            set v to |λ|(v, item i of xs, i, xs)        end repeat        return v    end tellend foldl -- map :: (a -> b) -> [a] -> [b]on map(f, xs)    tell mReturn(f)        set lng to length of xs        set lst to {}        repeat with i from 1 to lng            set end of lst to |λ|(item i of xs, i, xs)        end repeat        return lst    end tellend map -- Lift 2nd class handler function into 1st class script wrapper -- mReturn :: Handler -> Scripton mReturn(f)    if class of f is script then        f    else        script            property |λ| : f        end script    end ifend mReturn -- splitOn :: Text -> Text -> [Text]on splitOn(strDelim, strMain)    set {dlm, my text item delimiters} to {my text item delimiters, strDelim}    set xs to text items of strMain    set my text item delimiters to dlm    return xsend splitOn -- range :: (Int, Int) -> [Int]on tupleRange(tuple)    if tuple = {} then        {}    else if length of tuple > 1 then        enumFromTo(item 1 of tuple, item 2 of tuple)    else        item 1 of tuple    end ifend tupleRange`
Output:
`{-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20}`

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)}`

AWK

`#!/usr/bin/awk -fBEGIN {	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;} `
```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

`      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\$`
Output:
```-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
```

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")) `
Output:
`-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20`

C

Recursive descent parser.

`#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;}`
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#

Works with: C sharp version 3.0
`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+)-(?<s>-?\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));    }}`
Works with: C sharp version 3.5+
`using System;using System.Collections.Generic;using System.Linq; namespace RangeExpansion {  internal static class StringExtensions {    internal static IEnumerable<int> ExpandRange(this string s) {      return s.Split(',')        .Select(rstr => {          int start;          if (int.TryParse(rstr, out start))            return new {Start = start, End = start};          var istr = new string(("+-".Any(_ => rstr[0] == _)            ? rstr.Take(1).Concat(rstr.Skip(1).TakeWhile(char.IsDigit))            : rstr.TakeWhile(char.IsDigit)            ).ToArray());          rstr = rstr.Substring(istr.Length + 1, (rstr.Length - istr.Length) - 1);          return new {Start = int.Parse(istr), End = int.Parse(rstr)};        }).SelectMany(_ => Enumerable.Range(_.Start, _.End - _.Start + 1));    }  }   internal static class Program {    private static void Main() {      const string RANGE_STRING = "-6,-3--1,3-5,7-11,14,15,17-20";      var values = RANGE_STRING.ExpandRange().ToList();      var vstr = string.Join(", ", values.Select(_ => _.ToString()));      Console.WriteLine(vstr);    }  }}`

C++

`#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 otherwisetemplate<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.";}`
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)`.

`(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)`

COBOL

Works with: GNU Cobol version 2.0
`       >>SOURCE FREEIDENTIFICATION DIVISION.PROGRAM-ID. expand-range. DATA DIVISION.WORKING-STORAGE SECTION.01  comma-pos                           PIC 99 COMP VALUE 1.01  dash-pos                            PIC 99 COMP.01  end-num                             PIC S9(3).01  Max-Part-Len                        CONSTANT 10.01  num                                 PIC S9(3).01  edited-num                          PIC -(3)9.01  part                                PIC X(10). 01  part-flag                           PIC X.    88 last-part                        VALUE "Y". 01  range-str                           PIC X(80).01  Range-Str-Len                       CONSTANT 80.01  start-pos                           PIC 99 COMP.01  start-num                           PIC S9(3). PROCEDURE DIVISION.    ACCEPT range-str     PERFORM WITH TEST AFTER UNTIL last-part        UNSTRING range-str DELIMITED BY "," INTO part WITH POINTER comma-pos        PERFORM check-if-last         PERFORM find-range-dash         IF dash-pos > Max-Part-Len            PERFORM display-num        ELSE            PERFORM display-range        END-IF    END-PERFORM     DISPLAY SPACES     GOBACK    .check-if-last SECTION.    IF comma-pos > Range-Str-Len        SET last-part TO TRUE    END-IF    .find-range-dash SECTION.    IF part (1:1) <> "-"        MOVE 1 TO start-pos    ELSE        MOVE 2 TO start-pos    END-IF     MOVE 1 TO dash-pos    INSPECT part (start-pos:) TALLYING dash-pos FOR CHARACTERS BEFORE "-"    COMPUTE dash-pos = dash-pos + start-pos - 1    .display-num SECTION.    MOVE part TO edited-num    CALL "display-edited-num" USING CONTENT part-flag, edited-num    .display-range SECTION.    MOVE part (1:dash-pos - 1) TO start-num    MOVE part (dash-pos + 1:) TO end-num     PERFORM VARYING num FROM start-num BY 1 UNTIL num = end-num        MOVE num TO edited-num        CALL "display-edited-num" USING CONTENT "N", edited-num    END-PERFORM     MOVE end-num TO edited-num    CALL "display-edited-num" USING CONTENT part-flag, edited-num    .END PROGRAM expand-range.  IDENTIFICATION DIVISION.PROGRAM-ID. display-edited-num. DATA DIVISION.LINKAGE SECTION.01  hide-comma-flag                     PIC X.    88  hide-comma                      VALUE "Y".01  edited-num                          PIC -(3)9. PROCEDURE DIVISION USING hide-comma-flag, edited-num.    DISPLAY FUNCTION TRIM(edited-num) NO ADVANCING    IF NOT hide-comma        DISPLAY ", " NO ADVANCING    END-IF    .END PROGRAM display-edited-num.`

Setup:

```
\$ ./expand-range
-6,-3--1,3-5,7-11,14,15,17-20
```
Output:
```-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
```

Common 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)`

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;}`
Output:
`[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]`

DWScript

` function ExpandRanges(ranges : String) : array of Integer;begin   for var range in ranges.Split(',') do begin      var separator = range.IndexOf('-', 2);      if separator > 0 then begin         for var i := range.Left(separator-1).ToInteger to range.Copy(separator+1).ToInteger do            Result.Add(i);      end else begin         Result.Add(range.ToInteger)      end;   end;end; var expanded := ExpandRanges('-6,-3--1,3-5,7-11,14,15,17-20');PrintLn(JSON.Stringify(expanded)); `
Output:
`[-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20]`

Dyalect

Translation of: Go
`func main() {    const input = "-6,-3--1,3-5,7-11,14,15,17-20"     print("range: \(input)")    var r = []    var last = 0    for part in input.split(',') {        var i = part.sub(1).indexOf('-')        if  i == -1 {            var n = Integer(part)            if r.len() > 0 {                if last == n {                    print("duplicate value: \(n)")                    return                } else if last > n {                    print("values not ordered: \(last) > \(n)")                    return                }            }            r.add(n)            last = n        } else {            var n1 = Integer(part.sub(0, i+1))            var n2 = Integer(part.sub(i+2))            if n2 < n1+2 {                print("invalid range: \(part)")                return            }            if r.len() > 0 {                if last == n1 {                    print("duplicate value: \(n1)")                    return                } else if last > n1 {                    print("values not ordered: \(last) > \(n1)")                    return                }            }            for i in n1..n2 {                r.add(i)            }            last = n2        }    }     print("expanded: \(r)")} main()`
Output:
```range: -6,-3--1,3-5,7-11,14,15,17-20
expanded: [-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]```

EchoLisp

` ;; parsing [spaces][-]digit(s)-[-]digit(s)[spaces](define R (make-regexp "^ *(\-?\\d+)\-(\-?\\d+) *\$" )) ;; the native (range a b) is [a ... b[;; (range+ a b) is [a ... b](define (range+ a b)	(if (< a b) (range a (1+ b))	(if (> a b) (range a (1- b) -1)	(list a)))) ;; in : string : "number" or "number-number";; out : a range = list of integer(s)(define (do-range str) (define from-to (regexp-exec R str)) ;; "1-3" --> ("1" "3")(if from-to     (range+ (string->number (first from-to)) (string->number (second from-to)))    (list (string->number str)))) (define (ranges str)    (apply append (map do-range (string-split str ","))))  (define task "-6,-3--1,3-5,7-11,14,15,17-20")(ranges task)    → (-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20) `

Elixir

Translation of: Ruby
`defmodule RC do  def expansion(range) do    Enum.flat_map(String.split(range, ","), fn part ->      case Regex.scan(~r/^(-?\d+)-(-?\d+)\$/, part) do        [[_,a,b]] -> Enum.to_list(String.to_integer(a) .. String.to_integer(b))        [] -> [String.to_integer(part)]      end    end)  endend IO.inspect RC.expansion("-6,-3--1,3-5,7-11,14,15,17-20")`
Output:
```[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]
```

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) ). `
Output:
```34> range:task().
[-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20]
```

F#

`open System.Text.RegularExpressions // simplify regex matching with an active patternlet (|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 listlet 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")`
Output:
`[-6; -3; -2; -1; 3; 4; 5; 7; 8; 9; 10; 11; 14; 15; 17; 18; 19; 20]`

Factor

`R/ (?<=\d)-/ re-split` says: split only on hyphens immediately preceded by a digit.

`USING: kernel math.parser math.ranges prettyprint regexpsequences sequences.extras splitting ; : expand ( str -- seq )    "," split [        R/ (?<=\d)-/ re-split [ string>number ] map        dup length 2 = [ first2 [a,b] ] when    ] map-concat ; "-6,-3--1,3-5,7-11,14,15,17-20" expand .`
Output:
```{ -6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20 }
```

Forth

`: >snumber ( str len -- 'str 'len n )  0. 2swap  over [email protected] [char] - = if    1 /string    >number 2swap drop    negate  else    >number 2swap drop  then ; : expand ( str len -- )  begin dup while    >snumber >r    dup if over [email protected] [char] - = if      1 /string      >snumber r> over >r      do i . loop    then then    dup if over [email protected] [char] , = if      1 /string    then then    r> .  repeat 2drop ; s" -6,-3--1,3-5,7-11,14,15,17-20" expand`

Fortran

In order to save on the annoyance of having to declare the type of function ERANGE in each routine that invokes it (just one, here), the F90 MODULE protocol is convenient. F90 also allows for routines to contain service routines that share the context without massive parameter lists or shared COMMON areas, though alternatively, the shared variables could be inside the MODULE which would contain the service routines as separate routines also inside the module. But for this, one should not share variables having short names such as `I`. Otherwise, this would be F77 style except for the usage of the `I0` format code in subroutine SPLOT. If that were unavailable, code `I12` could be used and leading spaces would have to be skipped instead. The DO WHILE loop with its EXIT and labels would have to be less decorative for F77.

The standard problem of "How long is a piece of string?" applies yet again. Arrays and character variables have to be declared with some fixed size, and the usual approach is "surely big enough". The test input is not a problem, because the caller can use the needed size and pass that to ERANGE as a parameter, whatever its size. But function ERANGE's result must have some pre-declared size, and for this example, CHARACTER*200 will do. Via a great deal of blather, varying-size character variables can be defined and used in F90/95, and F2003 has standardised a method of doing this, whereby whenever something like `ALINE = ALINE // "stuff"` is executed, variable ALINE is reallocated with additional space. This involves copying the old content to the newly allocated larger storage area, so doing a lot of this would be bad snowballing.

The method is to grind through the input string expecting to find a number or a number - number pair (signed numbers allowed), followed by a comma if more is to follow. The state of the scan is represented by position within the scanning code rather than mess with state variables, so it is convenient to have service routines for the resulting repetition of basic actions. No checks are made for improper input, for instance a string ending with a comma. Those of a delicate disposition may be troubled by functions that don't just return a result but also mess with their parameter and change their environment. Here, the results from the functions assist with the flow of control through the scan, it is the side effects that manipulate the data.

A frustrating problem with many modern computer languages is the absence of a "shortcut" evaluation praxis for logical expressions; in Fortran's case the modern standard is that there is no standard. So a test `I<=LEN(TEXT) & TEXT(I:I)etc.` can't be relied upon to dodge out-of-bounds errors, and a flabby two-statement sequence is required instead. Similarly, few Fortran compilers allow for a function being evaluated via a WRITE statement to itself succeed in using a WRITE statement internally, though some do if one usage is free-format and the other formatted. If necessary, subroutine SPLOT could be re-written to convert an integer to a digit string without a WRITE statement, even for negative integers. And some compilers have difficulty with the use of the function name as a variable within the function so that it is safest to develop the result in an ordinary variable and then remember to assign its value to the function name just before exit.

A single number is made internally into a two-number range sequence, which values are used as the bounds for a DO-loop to generate the numbers for output. Despite the The range syntax is to be used only for, and for every range that expands to more than two values, I see no reason for this restriction (say because otherwise some fancy method would be stymied, except I can think of no such fancier method) and I have no desire to interpose some sort of error message, a tedious business that requires a wider interface between a routine and its caller. Similarly, if a range of 40-30 were to appear, why not take it at face value?
`      MODULE HOMEONTHERANGE       CONTAINS	!The key function.        CHARACTER*200 FUNCTION ERANGE(TEXT)	!Expands integer ranges in a list.Can't return a character value of variable size.         CHARACTER*(*) TEXT	!The list on input.         CHARACTER*200 ALINE	!Scratchpad for output.         INTEGER N,N1,N2	!Numbers in a range.         INTEGER I,I1		!Steppers.          ALINE = ""		!Scrub the scratchpad.          L = 0			!No text has been placed.          I = 1			!Start at the start.          CALL FORASIGN		!Find something to look at.Chug through another number or number - number range.        R:DO WHILE(EATINT(N1))	!If I can grab a first number, a term has begun.            N2 = N1			!Make the far end the same.            IF (PASSBY("-")) CALL EATINT(N2)	!A hyphen here is not a minus sign.            IF (L.GT.0) CALL EMIT(",")		!Another, after what went before?            DO N = N1,N2,SIGN(+1,N2 - N1)	!Step through the range, possibly backwards.              CALL SPLOT(N)				!Roll a number.              IF (N.NE.N2) CALL EMIT(",")		!Perhaps another follows.            END DO				!On to the next number.            IF (.NOT.PASSBY(",")) EXIT R	!More to come?          END DO R		!So much for a range.Completed the scan. Just return the result.          ERANGE = ALINE(1:L)	!Present the result. Fiddling ERANGE is bungled by some compilers.         CONTAINS	!Some assistants for the scan to save on repetition and show intent.          SUBROUTINE FORASIGN	!Look for one.    1       IF (I.LE.LEN(TEXT)) THEN	!After a thingy,              IF (TEXT(I:I).LE." ") THEN	!There may follow spaces.                I = I + 1				!So,                GO TO 1					!Speed past any.              END IF			!So that the caller can see            END IF			!Whatever substantive character follows.          END SUBROUTINE FORASIGN	!Simple enough.           LOGICAL FUNCTION PASSBY(C)	!Advances the scan if a certain character is seen.Could consider or ignore case for letters, but this is really for single symbols.           CHARACTER*1 C	!The character.            PASSBY = .FALSE.	!Pessimism.            IF (I.LE.LEN(TEXT)) THEN	!Can't rely on I.LE.LEN(TEXT) .AND. TEXT(I:I)...              IF (TEXT(I:I).EQ.C) THEN	!Curse possible full evaluation.                PASSBY = .TRUE.		!Righto, C is seen.                I = I + 1		!So advance the scan.                CALL FORASIGN		!And see what follows.              END IF		!So much for a match.            END IF		!If there is something to be uinspected.          END FUNCTION PASSBY	!Can't rely on testing PASSBY within PASSBY either.           LOGICAL FUNCTION EATINT(N)	!Convert text into an integer.           INTEGER N	!The value to be ascertained.           INTEGER D	!A digit.           LOGICAL NEG	!In case of a minus sign.            EATINT = .FALSE.	!Pessimism.            IF (I.GT.LEN(TEXT)) RETURN	!Anything to look at?            N = 0			!Scrub to start with.            IF (PASSBY("+")) THEN	!A plus sign here can be ignored.              NEG = .FALSE.		!So, there's no minus sign.             ELSE			!And if there wasn't a plus,              NEG = PASSBY("-")		!A hyphen here is a minus sign.            END IF			!One way or another, NEG is initialised.            IF (I.GT.LEN(TEXT)) RETURN	!Nothing further! We wuz misled!Chug through digits. Can develop -2147483648, thanks to the workings of two's complement.   10       D = ICHAR(TEXT(I:I)) - ICHAR("0")	!Hope for a digit.            IF (0.LE.D .AND. D.LE.9) THEN	!Is it one?              N = N*10 + D			!Yes! Assimilate it, negatively.              I = I + 1				!Advance one.              IF (I.LE.LEN(TEXT)) GO TO 10	!And see what comes next.            END IF			!So much for a sequence of digits.            IF (NEG) N = -N		!Apply the minus sign.            EATINT = .TRUE.		!Should really check for at least one digit.            CALL FORASIGN		!Ram into whatever follows.          END FUNCTION EATINT	!Integers are easy. Could check for no digits seen.           SUBROUTINE EMIT(C)	!Rolls forth one character.           CHARACTER*1 C	!The character.            L = L + 1		!Advance the finger.            IF (L.GT.LEN(ALINE)) STOP "Ran out of ALINE!"	!Maybe not.            ALINE(L:L) = C	!And place the character.          END SUBROUTINE EMIT	!That was simple.           SUBROUTINE SPLOT(N)	!Rolls forth a signed number.           INTEGER N		!The number.           CHARACTER*12 FIELD	!Sufficient for 32-bit integers.           INTEGER I		!A stepper.            WRITE (FIELD,"(I0)") N	!Roll the number, with trailing spaces.            DO I = 1,12		!Now transfer the ALINE of the number.              IF (FIELD(I:I).LE." ") EXIT	!Up to the first space.              CALL EMIT(FIELD(I:I))	!One by one.            END DO		!On to the end.          END SUBROUTINE SPLOT	!Not so difficult either.        END FUNCTION ERANGE	!A bit tricky.      END MODULE HOMEONTHERANGE       PROGRAM POKE      USE HOMEONTHERANGE      CHARACTER*(200) SOME      SOME = "-6,-3--1,3-5,7-11,14,15,17-20"      SOME = ERANGE(SOME)      WRITE (6,*) SOME	!If ERANGE(SOME) then the function usually can't write output also.      END`
Output:
` -6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20`

A check by using -2147483648 showed that EATINT develops the correct value even if N is built positively. Adding 8 to 2147483640 VIA `N = N*10 + D` indeed produces -2147483648 (and NEG was t), but the `IF (NEG) N = -N` still results in -2147483648 because of the working of (flip all bits and add one): invert(-2147483648) = 2147483647, and, adding one to that produces -2147483648.

FreeBASIC

`' FB 1.05.0 Win64 Sub split (s As Const String, sepList As Const String, result() As String)  If s = "" OrElse sepList = "" Then      Redim result(0)     result(0) = s     Return  End If  Dim As Integer i, j, count = 0, empty = 0, length  Dim As Integer position(Len(s) + 1)  position(0) = 0   For i = 0 To len(s) - 1    For j = 0 to Len(sepList) - 1      If s[i] = sepList[j] Then         count += 1        position(count) = i + 1             End If    Next j  Next i   Redim result(count)  If count  = 0 Then    result(0) = s    Return  End If   position(count + 1) = len(s) + 1   For i = 1 To count + 1      length = position(i) - position(i - 1) - 1     result(i - 1) = Mid(s, position(i - 1) + 1, length)  NextEnd Sub Function expandRange(s As Const String) As String  If s = "" Then Return ""  Dim b() As String  Dim c() As String   Dim result As String = ""   Dim As Integer start = 0, finish = 0, length  split s, ",", b()  For i As Integer = LBound(b) To UBound(b)    split b(i), "-", c()    length = UBound(c) - LBound(c) + 1    If length = 1 Then       start  = ValLng(c(LBound(c)))      finish = start    ElseIf length = 2 Then       If Left(b(i), 1) = "-" Then         start  = -ValLng(c(UBound(c)))         finish = start       Else         start  = ValLng(c(LBound(c)))         finish = ValLng(c(UBound(c)))       End If    ElseIf length = 3 Then      start  = -ValLng(c(LBound(c) + 1))      finish = ValLng(c(UBound(c)))     Else       start  = -ValLng(c(LBound(c) + 1))      finish = -ValLng(c(UBound(c)))    End If    For j As Integer = start To finish      result += Str(j) + ", "    Next j  Next i  Return Left(result, Len(result) - 2) '' get rid of final ", "End Function Dim s As String = "-6,-3--1,3-5,7-11,14,15,17-20"Print expandRange(s)PrintPrint "Press any key to quit"Sleep`
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

`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)}`

Groovy

1. translate the task's range syntax into Groovy range syntax
2. wrap with list delimiters
3. evaluate the script expression
4. flatten the nested lists
5. express as a string
6. unwrap the list delimiters
`def expandRanges = { compressed ->    Eval.me('['+compressed.replaceAll(~/(\d)-/, '\$1..')+']').flatten().toString()[1..-2]}`

Test:

`def s = '-6,-3--1,3-5,7-11,14,15,17-20'println (expandRanges(s))`
Output:
`-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20`

Given either of the below implementations of `expandRange`:

`> 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]`

With conventional list processing

`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`

With a parser

`{-# LANGUAGE FlexibleContexts #-} import Control.Applicative (Applicative((<*>), (*>)), (<\$>))import Text.Parsec expandRange :: String -> Maybe [Int]expandRange = either (const Nothing) Just . parse rangeParser "" rangeParser  :: (Enum a, Read a, Stream s m Char)  => ParsecT s u m [a]rangeParser = concat <\$> (item `sepBy` char ',')  where    item = do      n1 <- num      n2 <- option n1 (char '-' *> num)      return [n1 .. n2]    num = read `dot` (++) <\$> option "" (string "-") <*> many1 digit    dot = (.) . (.) main :: IO ()main = print \$ expandRange "-6,-3--1,3-5,7-11,14,15,17-20"`
Output:
`Just [-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20]`

Icon and Unicon

`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 representationlocal R,low,highR := [] 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 Rend procedure list2string(L)        #: helper function to convert a list to a stringlocal s    every (s := "[ ") ||:= !L || " "   return s || "]"end`
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

`require'strings'thru=: <. + [email protected](+*)@-~num=: _&".normaliz=: rplc&(',-';',_';'--';'-_')@,~&','subranges=:<@(thru/)@(num;._2)@,&'-';._1rngexp=: ;@[email protected]`
Example:
`   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`

Notes:

thru: given two integers (left: start of range, right: end of range) return the corresponding sequence of adjacent integers

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.

As an aside, note also that thru/ 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. Fortunately, this is consistent with the definition of thru (and is also consistent for any combining verb which has an identity element). Note that this is very similar to the self-justifying fold definition (specifically a right fold, because of J's structure), but fold can be considerably harder to reason about because it explicitly avoids the concept of identity for combining functions. You should maybe consider using a loop in contexts where this is an issue.

Also note that current versions of J no longer need `require'strings'` as those routines are included by default. (But let's leave this in place because current versions of J still have some catching up to do in some areas, such as lab support.)

Java

`import java.util.*; class RangeExpander implements Iterator<Integer>, Iterable<Integer> {     private static final Pattern TOKEN_PATTERN = Pattern.compile("([+-]?\\d+)-([+-]?\\d+)");     private final Iterator<String> tokensIterator;     private boolean inRange;    private int upperRangeEndpoint;    private int nextRangeValue;     public RangeExpander(String range) {        String[] tokens = range.split("\\s*,\\s*");        this.tokensIterator = Arrays.asList(tokens).iterator();    }     @Override    public boolean hasNext() {        return hasNextRangeValue() || this.tokensIterator.hasNext();    }     private boolean hasNextRangeValue() {        return this.inRange && this.nextRangeValue <= this.upperRangeEndpoint;    }     @Override    public Integer next() {        if (!hasNext()) {            throw new NoSuchElementException();        }         if (hasNextRangeValue()) {            return this.nextRangeValue++;        }         String token = this.tokensIterator.next();         Matcher matcher = TOKEN_PATTERN.matcher(token);        if (matcher.find()) {            this.inRange = true;            this.upperRangeEndpoint = Integer.valueOf(matcher.group(2));            this.nextRangeValue = Integer.valueOf(matcher.group(1));            return this.nextRangeValue++;        }         this.inRange = false;        return Integer.valueOf(token);    }     @Override    public Iterator<Integer> iterator() {        return this;    } } class RangeExpanderTest {    public static void main(String[] args) {        RangeExpander re = new RangeExpander("-6,-3--1,3-5,7-11,14,15,17-20");        for (int i : re) {            System.out.print(i + " ");        }    }}`

JavaScript

Imperative (Spidermonkey)

`#!/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(); `
Output:
```-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
```

Functional

ES5

`(function (strTest) {    'use strict';     // s -> [n]    function expansion(strExpr) {         // concat map yields flattened output list        return [].concat.apply([], strExpr.split(',')            .map(function (x) {                return x.split('-')                    .reduce(function (a, s, i, l) {                         // negative (after item 0) if preceded by an empty string                        // (i.e. a hyphen-split artefact, otherwise ignored)                        return s.length ? i ? a.concat(                            parseInt(l[i - 1].length ? s :                                '-' + s, 10)                        ) : [+s] : a;                    }, []);                 // two-number lists are interpreted as ranges            })            .map(function (r) {                return r.length > 1 ? range.apply(null, r) : r;            }));    }      // [m..n]    function range(m, n) {        return Array.apply(null, Array(n - m + 1))            .map(function (x, i) {                return m + i;            });    }     return expansion(strTest); })('-6,-3--1,3-5,7-11,14,15,17-20');`
Output:
`[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]`

ES6

`(strTest => {     // expansion :: String -> [Int]    let expansion = strExpr =>         // concat map yields flattened output list        [].concat.apply([], strExpr.split(',')            .map(x => x.split('-')                .reduce((a, s, i, l) =>                     // negative (after item 0) if preceded by an empty string                    // (i.e. a hyphen-split artefact, otherwise ignored)                    s.length ? i ? a.concat(                        parseInt(l[i - 1].length ? s :                            '-' + s, 10)                    ) : [+s] : a, [])                 // two-number lists are interpreted as ranges            )            .map(r => r.length > 1 ? range.apply(null, r) : r)),           // range :: Int -> Int -> Maybe Int -> [Int]        range = (m, n, step) => {            let d = (step || 1) * (n >= m ? 1 : -1);             return Array.from({                length: Math.floor((n - m) / d) + 1            }, (_, i) => m + (i * d));        };       return expansion(strTest); })('-6,-3--1,3-5,7-11,14,15,17-20');`
Output:
`[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]`

jq

Works with: jq version with regex support
`def expand_range:  def number: "-?[0-9]+";  def expand: [range(.[0]; .[1] + 1)];   split(",")  | reduce .[] as \$r      ( []; . +            (\$r | if test("^\(number)\$") then [tonumber]                  else sub( "(?<x>\(number))-(?<y>\(number))"; "\(.x):\(.y)")                  | split(":") | map(tonumber) | expand	          end));`

Example:

`"-6,-3--1,3-5,7-11,14,15,17-20" | expand_range`
Output:
\$ jq -c -n -f Range_expansion.jq

[-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20]

Jsish

Translation of: Javascript
`#!/usr/bin/env jsish"use strict"; /* Range expansion, in Jsish */ 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;} if (Interp.conf('unitTest')) {;    rangeExpand('-6,-3--1,3-5,7-11,14,15,17-20');} /*=!EXPECTSTART!=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 ]=!EXPECTEND!=*/`
Output:
```prompt\$ jsish --U rangeExpansion.jsi
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 ]```

Julia

`slurp(s) = readcsv(IOBuffer(s)) conv(s)= colon(map(x->parse(Int,x),match(r"^(-?\d+)-(-?\d+)\$", s).captures)...) expand(s) = mapreduce(x -> isa(x,Number)? Int(x) : conv(x), vcat, slurp(s))`
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

`grp : {1_'(&x=*x)_ x:",",x}pos : {:[3=l:#p:&"-"=x;0,[email protected];2=l;p;0=*p;,0;0,p]}conv: 0\${(x;1_ y)}/'{(pos x)_ x}'expd: {,/@[x;&2=#:'x;{(*x)+!1+,/-':x}]}rnge: {[email protected] grp x}`
Example:
`  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`

Kotlin

`// version 1.0.6 fun expandRange(s: String): MutableList<Int> {    val list = mutableListOf<Int>()        val items = s.split(',')    var first: Int    var last:  Int    for (item in items) {        val count = item.count { it == '-' }        if (count == 0 || (count == 1 && item[0] == '-'))            list.add(item.toInt())        else {            val items2 = item.split('-')            if (count == 1) {                first = items2[0].toInt()                last  = items2[1].toInt()                        }            else if (count == 2) {                first = items2[1].toInt() * -1                last  = items2[2].toInt()            }            else {                first = items2[1].toInt() * -1                last  = items2[3].toInt() * -1            }            for (i in first..last) list.add(i)         }    }    return list}   fun main(args: Array<String>) {    val s = "-6,-3--1,3-5,7-11,14,15,17-20"    println(expandRange(s))}`
Output:
```[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]
```

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`)`
Output:
`-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20`

Liberty BASIC

`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    wendend function`
Output:
`-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20`

Lingo

`-- Note: currently does not support extra white space in input stringon expandRange (str)  res = ""  _player.itemDelimiter = ","  cnt = str.item.count  repeat with i = 1 to cnt    part = str.item[i]    pos = offset("-", part.char[2..part.length])    if pos>0 then      a = integer(part.char[1..pos])      b = integer(part.char[pos+2..part.length])      repeat with j = a to b        put j&"," after res      end repeat    else      put part&"," after res    end if  end repeat  delete the last char of res  return resend`
`put 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"`

LiveCode

`function range beginning ending stepping    local tRange, tBegin, tEnd, tstep    if stepping is empty or stepping is 0 then        put 1 into tstep    else        put abs(stepping) into tstep    end if     if ending is empty or isNumber(ending) is not true then        put 0 into tEnd    else        put ending into tEnd    end if     if beginning is empty or isNumber(beginning) is not true then        put 0 into tBegin    else        put beginning into tBegin    end if     repeat with r = tBegin to tEnd step tstep        put space & r after tRange    end repeat    return word 1 to -1 of tRangeend range function expandRange rangeExpr    put rangeExpr into tRange    split tRange by comma    repeat with n = 1 to the number of elements of tRange        if matchText(tRange[n],"^(\-*\d+)\-(\-*\d+)",beginning, ending) then            put range(beginning, ending, 1) & space after z        else            put tRange[n] & space after z        end if    end repeat    return zend expandRange`

Test

`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 `

Lua

`function range(i, j)    local t = {}    for n = i, j, i<j and 1 or -1 do        t[#t+1] = n    end    return tend function expand_ranges(rspec)    local ptn = "([-+]?%d+)%s?-%s?([-+]?%d+)"    local t = {}     for v in string.gmatch(rspec, '[^,]+') do        local s, e = v:match(ptn)         if s == nil then            t[#t+1] = tonumber(v)        else            for i, n in ipairs(range(tonumber(s), tonumber(e))) do                t[#t+1] = n            end        end    end    return tend local ranges = "-6,-3--1,3-5,7-11,14,15,17-20"print(table.concat(expand_ranges(ranges), ', '))`

Due to the way Lua's `tonumber` function works and the way the string pattern to parse ranges is written, whitespace is allowed around commas and the dash separating the range start and end (but not between the plus/minus sign and the number).

Output:
```    -6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
```

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: `

Running this on the example input we get the following.

` > 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] `

Here is an additional example which my first attempt got wrong.

` > 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] `

Mathematica

`rangeexpand[ rng_ ] := Module[ { step1 },step1 = StringSplit[StringReplacePart[rng,"S",StringPosition[ rng,DigitCharacter~~"-"] /. {x_,y_} -> {y,y}],","];[email protected]/@[email protected][step1,x__~~"S"~~y__->"Range["<>x<>","<>y<>"]"] ]`
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

`function L=range_expansion(S)% Range expansionif nargin < 1; 	S='[]';end if ~all(isdigit(S) | (S=='-')  | (S==',') | isspace(S))	error 'invalid input';endixr = find(isdigit(S(1:end-1)) & S(2:end) == '-')+1;S(ixr)=':';S=['[',S,']'];L=eval(S);`

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

```

MiniScript

`pullInt = function(chars)    numstr = chars.pull    while chars and chars[0] != "," and chars[0] != "-"        numstr = numstr + chars.pull    end while    return val(numstr)end function expandRange = function(s)    result = []    chars = s.split("")    while chars        num = pullInt(chars)        if not chars or chars.pull == "," then            result.push num        else            result = result + range(num, pullInt(chars))            chars.pull  // skip "," after range        end if    end while    return resultend function print expandRange("-6,-3--1,3-5,7-11,14,15,17-20")`
Output:
`[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]`

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`
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

`/*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 oldif 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         */ `
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
```

Nim

`import parseutils, re, strutils proc expandRange(input: string): string =  var output: seq[string] = @[]  for range in input.split(','):    var sep = range.find('-', 1)    if sep > 0: # parse range      var first = -1      if range.substr(0, sep-1).parseInt(first) == 0:        break      var last = -1      if range.substr(sep+1).parseInt(last) == 0:        break      for i in first..last:        output.add(\$i)    else: # parse single number      var n = -1      if range.parseInt(n) > 0:        output.add(\$n)      else:        break  return output.join(",") echo("-6,-3--1,3-5,7-11,14,15,17-20".expandRange)`
Output:
`-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20`

Oberon-2

Oxford Oberon-2

` 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 * numEND 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.  `
Output:
```-6, -3, -2, -1,  3,  4,  5,  7,  8,  9, 10, 11, 14, 15, 17, 18, 19, 20
```

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 ()`

Oforth

`: addRange( s res -- )| i n |    s asInteger dup ifNotNull: [ res add return ] drop    s indexOfFrom('-', 2) ->i    s left( i 1- ) asInteger  s right( s size i - ) asInteger    for: n [ n res add ]; : rangeExpand ( s -- [ n ] )    ArrayBuffer new  s wordsWith( ',' ) apply( #[ over addRange ] ) ;`

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 `
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

`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}  endin  {System.showInfo   {Value.toVirtualString {Expand "-6,-3--1,3-5,7-11,14,15,17-20"} 100 100}}`
Sample output:
`[~6 ~3 ~2 ~1 3 4 5 7 8 9 10 11 14 15 17 18 19 20]`

Perl

One-liner:

`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";`
Output:
`-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20`

Alternative:

`sub rangex {    (my \$range = shift) =~ s/(?<=\d)-/../g;    eval \$range;}`

Phix

`function range_expansion(string range)sequence s = split(range,','),         res = {}    for i=1 to length(s) do        string si = s[i]        integer k = find('-',si,2)        if k=0 then            res = append(res,to_number(si))        else            integer startrange = to_number(si[1..k-1])            integer endofrange = to_number(si[k+1..\$])            for l=startrange to endofrange do                res = append(res,l)            end for        end if    end for    return resend function ?range_expansion("-6,-3-1,3-5,7-11,14,15,17-20")?range_expansion("-6,-3--1,3-5,7-11,14,15,17-20")`
Output:
```{-6,-3,-2,-1,0,1,3,4,5,7,8,9,10,11,14,15,17,18,19,20}
{-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20}
```

Phixmonti

Require Phixmonti 1.1

`0 tolist var r def append    r swap 0 put var renddef "-6,-3--1,3-5,7-11,14,15,17-20" "," " " subst split len for    get dup tonum dup    nan == if        drop        dup len 1 - 2 swap slice        "-" find dup 2 + rot drop        rot rot 1 swap slice tonum        rot rot len rot swap over - 1 + slice tonum        nip rot drop        2 tolist for append endfor    else        append drop    endifendforrpstack`

Other solution

`0 tolist var r def append    r swap 0 put var renddef "-6,-3--1,3-5,7-11,14,15,17-20" "," " " subst split len for    get dup tonum dup    nan == if        drop        dup 32 1 set        "-" find nip        swap over 1 - 1 swap slice tonum        rot rot len rot swap over - swap 1 + swap slice tonum        nip 2 tolist for append endfor    else        append drop    endifendforrpstack`

A bit more understandable

`0 tolist var r def append    r swap 0 put var renddef def getSeparator    /# s -- s n #/    dup 32 1 set    "-" find nipenddef def first   /# s n -- s n #/    swap over 1 - 1    swap slice tonumenddef def last    /# s n -- s n #/    swap len rot swap over - swap 1 +    swap slice tonumenddef "-6,-3--1,3-5,7-11,14,15,17-20" "," " " subst split len for    get dup tonum dup    nan == if        drop        getSeparator        first        rot rot swap        last        nip 2 tolist for append endfor    else        append drop    endifendforrpstack`

PHP

Translation of: Python
`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;}`

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)) ) ) ) )`
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

`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;`
Output:
```  -6, -3, -2, -1,  3,  4,  5,  7,  8,  9, 10, 11, 14, 15, 17, 18, 19, 20
```

PowerShell

` function range-expansion(\$array) {    function expansion(\$arr) {         if(\$arr) {            \$arr = \$arr.Split(',')             \$arr | foreach{                \$a = \$_                \$b, \$c, \$d, \$e = \$a.Split('-')                switch(\$a) {                    \$b {return \$a}                    "-\$c" {return \$a}                    "\$b-\$c" {return "\$(([Int]\$b)..([Int]\$c))"}                    "-\$c-\$d" {return "\$(([Int]\$("-\$c"))..([Int]\$d))"}                    "-\$c--\$e" {return "\$(([Int]\$("-\$c"))..([Int]\$("-\$e")))"}                }             }        } else {""}    }    \$OFS = ", "    "\$(expansion \$array)"    \$OFS = " "}range-expansion "-6,-3--1,3-5,7-11,14,15,17-20" `

Output:

```-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
```

Alternate Half-Assed Regex Version

Ten times faster (only minimally tested).

` function Expand-Range{    [CmdletBinding()]    [OutputType([int])]    Param    (        [Parameter(Mandatory=\$true,                    Position=0)]        [ValidateNotNullOrEmpty()]        [ValidatePattern('^[0-9,-]*\$')]        [string]        \$Range    )     try    {        if (\$Range -match '-,')       # I'm not good enough to weed this case out with Regex        {            throw "Input string was not in a correct format."        }         [int[]]\$output = \$Range -split ',' | ForEach-Object {             [int[]]\$array = \$_ -split '(?<=\d)-'               if (\$array.Count -gt 1)   # \$array contains one or two elements            {                \$array[0]..\$array[1]  # two elements = start and end of range            }            else            {                \$array                # one element = an integer            }        }    }    catch    {        throw "Input string was not in a correct format."    }     \$output} `
` (Expand-Range "-6,-3--1,3-5,7-11,14,15,17-20") -join ", " `
Output:
```-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
```

Prolog

Works with: SWI Prolog
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.

`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]).`
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

`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   NextEndProcedure  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`
Output:
`[ -6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20 ]`

Python

Procedural

`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'))`

another variant, using regular expressions to parse the ranges,

`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`

Functional

As a fold/catamorphism:

Works with: Python version 3.7
`'''Range expansion''' from functools import (reduce)  # rangeExpansion :: String -> [Int]def rangeExpansion(s):    '''List of integers expanded from a       comma-delimited string of individual       numbers and hyphenated ranges.    '''    def go(a, x):        tpl = breakOn('-')(x[1:])        r = tpl[1]        return a + (            [int(x)] if not r            else enumFromTo(int(x[0] + tpl[0]))(                int(r[1:])            )        )    return reduce(go, s.split(','), [])  # TEST ----------------------------------------------------def main():    '''Expansion test'''     print(        fTable(__doc__ + ':')(            lambda x: "\n'" + str(x) + "'"        )(lambda x: '\n\n\t' + showList(x))(            rangeExpansion        )([            '-6,-3--1,3-5,7-11,14,15,17-20'        ])    )  # GENERIC FUNCTIONS --------------------------------------- # breakOn :: String -> String -> (String, String)def breakOn(needle):    '''A tuple of:       1. the prefix of haystack before needle,       2. the remainder of haystack, starting          with needle.    '''    def go(haystack):        xs = haystack.split(needle)        return (xs[0], haystack[len(xs[0]):]) if (            1 < len(xs)        ) else (haystack, '')    return lambda haystack: go(haystack) if (        needle    ) else None  # enumFromTo :: (Int, Int) -> [Int]def enumFromTo(m):    '''Integer enumeration from m to n.'''    return lambda n: list(range(m, 1 + n))  # fTable :: String -> (a -> String) ->#                     (b -> String) ->#        (a -> b) -> [a] -> Stringdef fTable(s):    '''Heading -> x display function -> fx display function ->          f -> value list -> tabular string.'''    def go(xShow, fxShow, f, xs):        w = max(map(lambda x: len(xShow(x)), xs))        return s + '\n' + '\n'.join([            xShow(x).rjust(w, ' ') + (                ' -> '            ) + fxShow(f(x)) for x in xs        ])    return lambda xShow: lambda fxShow: (        lambda f: lambda xs: go(            xShow, fxShow, f, xs        )    )  # showList :: [a] -> Stringdef showList(xs):    '''Stringification of a list.'''    return '[' + ','.join(str(x) for x in xs) + ']'  # MAIN ---if __name__ == '__main__':    main()`
Output:
```Range expansion:

'-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]```

R

` rangeExpand <- function(text) {  lst <- gsub("(\\d)-", "\\1:", unlist(strsplit(text, ",")))  unlist(sapply(lst, function (x) eval(parse(text=x))), use.names=FALSE)} 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 `

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") `
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 (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")) `

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)
```

Raku

(formerly Perl 6)

Works with: Rakudo version 2016.07
`sub range-expand (Str \$range-description) {    my token number { '-'? \d+ }    my token range  { (<&number>) '-' (<&number>) }     \$range-description        .split(',')        .map({ .match(&range) ?? \$0..\$1 !! +\$_ })        .flat} say range-expand('-6,-3--1,3-5,7-11,14,15,17-20').join(', ');`
Output:
`-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20`

Alternatively, using a grammar:

`grammar RangeList {    token TOP    { <term>* % ','    { make \$<term>.map(*.made)       } }    token term   { [<range>|<num>]  { make (\$<num> // \$<range>).made } }    token range  { <num> '-' <num>  { make +\$<num>[0] .. +\$<num>[1]  } }    token num    { '-'? \d+         { make +\$/                       } }} say RangeList.parse('-6,-3--1,3-5,7-11,14,15,17-20').made.flat.join(', ');`
Output:
`-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20`

Raven

Based loosely on Ruby

`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`
Output:
`-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20`

REXX

version 1

Extra imbedded blanks were added to the   old   list (which are ignored) to make the   over/under   comparison easier   (in the output).

`/*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=                                             /*translate [↑]  commas (,) ───► blanks*/      do until a=='';   parse var a X a          /*obtain the next integer ──or── range.*/      p=pos('-', X, 2)                           /*find the location of a dash (maybe). */      if p==0 then  new=new   X                  /*append integer   X   to the new list.*/              else  do j=left(X,p-1)  to substr(X,p+1);     new=new j                    end   /*j*/                  /*append a single [↑] integer at a time*/      end                 /*until*/                                                 /*stick a fork in it,  we're all done. */new=translate( strip(new),  ',',  " ")           /*remove the first blank,  add commas. */say 'old list: '   old                           /*show the  old list of numbers/ranges.*/say 'new list: '   new                           /*  "   "   new   "   " numbers.       */`

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 !?!

`/*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         */`
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
```

Ring

` # Project : Range expansion int = "-6,-3--1,3-5,7-11,14,15,17-20"int = str2list(substr(int, ",", nl))newint = []for n=1 to len(int)     nrint = substr(int[n], "-")     nrint2 = substr(int[n], "--")     if nrint2 > 0        temp1 = left(int[n], nrint2 -1)        temp2 = right(int[n], len(int[n]) - nrint2)        add(newint, [temp1,temp2])     else        if len(int[n]) <= 2           add(newint, [int[n], ""])        else            if nrint > 0 and nrint2 = 0              temp1 = left(int[n], nrint - 1)              temp2 = right(int[n], len(int[n]) - nrint)              add(newint, [temp1,temp2])            ok          ok     oknextshowarray(newint) func showarray(vect)       see "["       svect = ""       for n = 1 to len(vect)           if newint[n][2] != ""              for nr = newint[n][1] to newint[n][2]                  svect = svect +"" + nr + ", "              next           else              svect = svect +"" + newint[n][1] + ", "           ok       next       svect = left(svect, len(svect) - 2)       see svect       see "]" + nl `

Output:

```[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]
```

Ruby

`def range_expand(rng)  rng.split(',').flat_map do |part|    if part =~ /^(-?\d+)-(-?\d+)\$/      (\$1.to_i .. \$2.to_i).to_a    else      Integer(part)    end  endend p range_expand('-6,-3--1,3-5,7-11,14,15,17-20')`
Output:
`[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]`

Run BASIC

`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 ifend ifif i <> 0 then goto [loop]rangeExpand\$ = range\$end function`
Output:
`-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20`

Rust

Rust doesn't have regex in standard library yet.

`use std::str::FromStr; // Precondition: range doesn't contain multibyte UTF-8 charactersfn range_expand(range : &str) -> Vec<i32> {   range.split(',').flat_map(|item| {        match i32::from_str(item) {            Ok(n) => n..n+1,            _ => {                let dashpos=                    match item.rfind("--") {                        Some(p) => p,                        None => item.rfind('-').unwrap(),                    };                let rstart=i32::from_str(                    unsafe{ item.slice_unchecked(0,dashpos)} ).unwrap();                let rend=i32::from_str(                    unsafe{ item.slice_unchecked(dashpos+1,item.len()) } ).unwrap();                rstart..rend+1            },        }    }).collect()} fn main() {    println!("{:?}", range_expand("-6,-3--1,3-5,7-11,14,15,17-20"));} `
Output:
```[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]
```

S-lang

`variable r_expres = "-6,-3--1,3-5,7-11,14,15,17-20", s, r_expan = {}, dpos, i; foreach s (strchop(r_expres, ',', 0)){  % S-Lang built-in RE's are fairly limited, and have a quirk:  %   grouping is done with \\( and \\), not ( and )  % [PCRE and Oniguruma RE's are available via standard libraries]  if (string_match(s, "-?[0-9]+\\(-\\)-?[0-9]+", 1)) {     (dpos, ) = string_match_nth(1);     % Create/loop-over a "range array": from num before - to num after it:    foreach i ( [integer(substr(s, 1, dpos)) : integer(substr(s, dpos+2, -1))] )      list_append(r_expan, string(i));  }  else    list_append(r_expan, s);}print(strjoin(list_to_array(r_expan), ", "));`

Scala

`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  }`
Output:
```> println(rangex("-6,-3-1,3-5,7-11,14,15,17-20"))
ArraySeq(-6, -3, -2, -1, 0, 1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20)
> println(rangex("-6,-3--1,3-5,7-11,14,15,17-20"))
ArraySeq(-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20)```

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)))`
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.

`\$ 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;`
Output:
```-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20
```

Sidef

`func rangex(str) {    str.split(',').map { |r|        var m = r.match(/^            (?(DEFINE) (?<int>[+-]?[0-9]+) )            (?<from>(?&int))-(?<to>(?&int))        \$/x)        m ? do {var c = m.ncap; (Num(c{:from}) .. Num(c{:to}))...}          : Num(r)    }} say rangex('-6,-3--1,3-5,7-11,14,15,17-20').join(',')`
Output:
`-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20`

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`
Output:
`-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20`

Tailspin

` composer expand  [<element>*]  rule element: <range|INT> (<','>?)  rule range: (def start: <INT>; <'-'>) <INT> -> \$start..\$end expand '-6,-3--1,3-5,7-11,14,15,17-20' -> expand -> !OUT::write `
Output:
```[-6, -3, -2, -1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20]
```

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"]`
Output:
`-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20`

TUSCRIPT

`\$\$ MODE TUSCRIPTrangednrs="-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 ENDIFENDLOOPexpandnrs= JOIN (expandnrs,",") PRINT expandnrs`
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:

`@(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 rangeexpand (list)     (uniq (expand-helper list))))@(repeat)@(rangelist x)@{trailing-junk}@(output)raw syntax: @xexpansion:  @(rangeexpand x)your junk:  @{trailing-junk}@(end)@(end)`
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)
-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)
-6,-3--1,3-5,7-11,14,15,17-20,[email protected]
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)

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

Works with: bash
`#!/usr/bin/bash range_expand () (    IFS=,    set -- \$1    n=\$#    for element; do        if [[ \$element =~ ^(-?[0-9]+)-(-?[0-9]+)\$ ]]; then            set -- "[email protected]" \$(eval echo "{\${BASH_REMATCH[1]}..\${BASH_REMATCH[2]}}")        else            set -- "[email protected]" \$element        fi    done    shift \$n    echo "[email protected]"    # to return a comma-separated value: echo "\${*// /,}") range_expand "-6,-3--1,3-5,7-11,14,15,17-20"`
Output:
`-6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20`

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'`
Output:
`<-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20>`

VBA

`Public Function RangeExpand(AString as string)' return a list with the numbers expressed in AStringDim Splits() As StringDim List() As IntegerDim count As Integer count = -1 'to start a zero-based List() array' first split it using comma as delimiterSplits = Split(AString, ",")' process all fragmentsFor 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 IfNextRangeExpand = ListEnd Function Public Sub RangeExpandTest()'test function RangeExpandDim X As Variant X = RangeExpand("-6,-3--1,3-5,7-11,14,15,17-20")'print XDebug.Print "Result:"For Each el In X  Debug.Print el;NextDebug.PrintEnd Sub`
Output:
```RangeExpandTest
Result:
-6 -3 -2 -1  3  4  5  7  8  9  10  11  14  15  17  18  19  20
```

XPL0

`include c:\cxpl\codes;          \intrinsic 'code' declarationsstring 0;                       \use zero-terminated strings, instead of MSbchar 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 valueint 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 aheadloop    [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);]`
Output:
```-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
```

Yabasic

`print RangeExpand\$("-6,-3--1,3-5,7-11,14,15,17-20") sub RangeExpand\$(s\$)    local w\$(1), n, i, r\$, p, a, b     n = token(s\$, w\$(), ",")     for i = 1 to n        p = instr(w\$(i), "-", 2)        if p then            a = val(left\$(w\$(i), p-1))            b = val(right\$(w\$(i), len(w\$(i)) - p))            repeat                r\$ = r\$ + str\$(a) + ","                a = a + 1            until(a > b)        else            r\$ = r\$ + w\$(i) + ","        end if    next    return left\$(r\$, len(r\$) - 1)end sub `

zkl

`fcn rangex(s){   fcn(s,re){      if (re.search(s)){	 a,b:=re.matched[1,*].apply("toInt");	 [a..b].walk();      }      else s;   } :   s.split(",").pump(List, _.fp1(RegExp(0'|(.*\d+)-(.*\d+)|)))      .flatten().concat(",");}`
`ns="-6,-3-1,3-5,7-11,14,15,17-20";rangex(ns).println(); ns="-6,-3--1,3-5,7-11,14,15,17-20";rangex(ns).println();`
Output:
```-6,-3,-2,-1,0,1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20
```