Anonymous user
Brace expansion using ranges: Difference between revisions
→{{header|Nim}}
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stops after endpoint-08.txt
</pre>
=={{header|Nim}}==
{{trans|Wren}}
<lang Nim>import options, strutils, unicode
func intFromString(s: string): Option[int] =
## Try to parse an int. Return some(int) if parsing
## was successful, return none(int) if it failed.
try:
let n = s.parseInt()
result = some(n)
except ValueError:
result = none(int)
func parseRange(r: string): seq[string] =
if r.len == 0: return @["{}"] # rangeless, empty.
let sp = r.split("..")
if sp.len == 1: return @['{' & r & '}']
let first = sp[0]
let last = sp[1]
let incr = if sp.len == 2: "1" else: sp[2]
let val1 = intFromString(first)
let val2 = intFromString(last)
let val3 = intFromString(incr)
if val3.isNone(): return @['{' & r & '}'] # increment isn't a number.
var n3 = val3.get()
let numeric = val1.isSome and val2.isSome
var n1, n2: int
if numeric:
n1 = val1.get()
n2 = val2.get()
else:
if val1.isSome and val2.isNone or val1.isNone and val2.isSome:
return @['{' & r & '}'] # mixed numeric/alpha not expanded.
if first.runeLen != 1 or last.runeLen != 1:
return @['{' & r & '}'] # start/end are not both single alpha.
n1 = first.toRunes[0].int
n2 = last.toRunes[0].int
var width = 1
if numeric:
width = if first.len < last.len: last.len else: first.len
if n3 == 0:
# Zero increment.
return if numeric: @[n1.intToStr(width)] else: @[first]
var asc = n1 < n2
if n3 < 0:
asc = not asc
swap n1, n2
n3 = -n3
var i = n1
if asc:
while i <= n2:
result.add if numeric: i.intToStr(width) else: $Rune(i)
inc i, n3
else:
while i >= n2:
result.add if numeric: i.intToStr(width) else: $Rune(i)
dec i, n3
func rangeExpand(s: string): seq[string] =
result = @[""]
var rng = ""
var inRng = false
for c in s:
if c == '{' and not inRng:
inRng = true
rng = ""
elif c == '}' and inRng:
let rngRes = rng.parseRange()
var res: seq[string]
for i in 0..result.high:
for j in 0..rngRes.high:
res.add result[i] & rngRes[j]
result = move(res)
inRng = false
elif inRng:
rng.add c
else:
for s in result.mitems: s.add c
if inRng:
for s in result.mitems: s.add '{' & rng # unmatched braces.
when isMainModule:
const Examples = ["simpleNumberRising{1..3}.txt",
"simpleAlphaDescending-{Z..X}.txt",
"steppedDownAndPadded-{10..00..5}.txt",
"minusSignFlipsSequence {030..20..-5}.txt",
"combined-{Q..P}{2..1}.txt",
"emoji{🌵..🌶}{🌽..🌾}etc",
"li{teral",
"rangeless{}empty",
"rangeless{random}string",
"mixedNumberAlpha{5..k}",
"steppedAlphaRising{P..Z..2}.txt",
"stops after endpoint-{02..10..3}.txt"]
for s in Examples:
stdout.write s, " →\n "
let res = rangeExpand(s)
stdout.write res.join("\n ")
echo '\n'</nim>
{{out}}
<pre>simpleNumberRising{1..3}.txt →
simpleNumberRising1.txt
simpleNumberRising2.txt
simpleNumberRising3.txt
simpleAlphaDescending-{Z..X}.txt →
simpleAlphaDescending-Z.txt
simpleAlphaDescending-Y.txt
simpleAlphaDescending-X.txt
steppedDownAndPadded-{10..00..5}.txt →
steppedDownAndPadded-10.txt
steppedDownAndPadded-05.txt
steppedDownAndPadded-00.txt
minusSignFlipsSequence {030..20..-5}.txt →
minusSignFlipsSequence 020.txt
minusSignFlipsSequence 025.txt
minusSignFlipsSequence 030.txt
combined-{Q..P}{2..1}.txt →
combined-Q2.txt
combined-Q1.txt
combined-P2.txt
combined-P1.txt
emoji{🌵..🌶}{🌽..🌾}etc →
emoji🌵🌽etc
emoji🌵🌾etc
emoji🌶🌽etc
emoji🌶🌾etc
li{teral →
li{teral
rangeless{}empty →
rangeless{}empty
rangeless{random}string →
rangeless{random}string
mixedNumberAlpha{5..k} →
mixedNumberAlpha{5..k}
steppedAlphaRising{P..Z..2}.txt →
steppedAlphaRisingP.txt
steppedAlphaRisingR.txt
steppedAlphaRisingT.txt
steppedAlphaRisingV.txt
steppedAlphaRisingX.txt
steppedAlphaRisingZ.txt
stops after endpoint-{02..10..3}.txt →
stops after endpoint-02.txt
stops after endpoint-05.txt
stops after endpoint-08.txt</pre>
=={{header|Phix}}==
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