Brace expansion: Difference between revisions

=={{header|Nim}}==

{{trans|Seed7}}

<lang Nim>proc expandBraces(str: string) =

var

escaped = false

depth = 0

bracePoints: seq[int]

bracesToParse: seq[int]

for idx, ch in str:

case ch

of '\\':

escaped = not escaped

of '{':

inc depth

if not escaped and depth == 1:

bracePoints = @[idx]

of ',':

if not escaped and depth == 1:

bracePoints &= idx

of '}':

if not escaped and depth == 1 and bracePoints.len >= 2:

bracesToParse = bracePoints & idx

dec depth

else:

discard

if ch != '\\':

escaped = false

if bracesToParse.len > 0:

let prefix = str[0..<bracesToParse[0]]

let suffix = str[(bracesToParse[^1] + 1)..^1]

for idx in 1..bracesToParse.high:

let option = str[(bracesToParse[idx - 1] + 1)..(bracesToParse[idx] - 1)]

expandBraces(prefix & option & suffix)

else:

echo " ", str

#———————————————————————————————————————————————————————————————————————————————————————————————————

when isMainModule:

for str in ["It{{em,alic}iz,erat}e{d,}, please.",

"~/{Downloads,Pictures}/*.{jpg,gif,png}",

"{,{,gotta have{ ,\\, again\\, }}more }cowbell!",

"{}} some }{,{\\\\{ edge, edge} \\,}{ cases, {here} \\\\\\\\\\}"]:

echo "\nExpansions of \"", str, "\":"

expandBraces(str)</lang>

{{out}}

<pre>

Expansions of "It{{em,alic}iz,erat}e{d,}, please.":

Itemized, please.

Italicized, please.

Iterated, please.

Itemize, please.

Italicize, please.

Iterate, please.

Expansions of "~/{Downloads,Pictures}/*.{jpg,gif,png}":

~/Downloads/*.jpg

~/Pictures/*.jpg

~/Downloads/*.gif

~/Pictures/*.gif

~/Downloads/*.png

~/Pictures/*.png

Expansions of "{,{,gotta have{ ,\, again\, }}more }cowbell!":

cowbell!

more cowbell!

gotta have more cowbell!

gotta have\, again\, more cowbell!

Expansions of "{}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\}":

{}} some }{,{\\ edge \,}{ cases, {here} \\\\\}

{}} some }{,{\\ edge \,}{ cases, {here} \\\\\}</pre>