Pyparsing nested transformString

Question

I had something working for a little while to transform a tag from lua to hmtl, but recently I got a special case where those tags could be nested. Here is a quick sample out of my code :

from pyparsing import Literal, Word, Suppress, SkipTo, LineEnd, hexnums

text = "|c71d5FFFFI'm saying something in color|cFFFFFFFF then in white |r|r"

def colorize (t):
    hexRGB = "".join(list(t.hex)[:6])
    return "<span style=\"color:#{};\">{}</span>".format(hexRGB, t.content)

vbar = Literal("|")
eol = LineEnd().suppress()

endTag = ((vbar + (Literal("r")|Literal("R"))|eol))
parser = (
    Suppress(vbar + (Literal("c")|Literal("C"))) + 
    Word(hexnums, exact=8).setResultsName("hex") + 
    SkipTo(endTag).setResultsName("content") + 
    Suppress(endTag)
).addParseAction(colorize)

result = parser.transformString(text)
print (result)

I saw an another similar question Pyparsing: nested Markdown emphasis, but my problem is a bit different, sometime there is no closetag and lineEnd is acting as one.

Answer 1

You can add a while loop to iterate over result until all the colors are found:

from pyparsing import Literal, Word, Suppress, SkipTo, LineEnd, hexnums


def colorize (t):
    hexRGB = "".join(list(t.hex)[:6])
    return "<span style=\"color:#{};\">{}</span>".format(hexRGB, t.content)

vbar = Literal("|")
eol = LineEnd().suppress()

endTag = ((vbar + (Literal("r")|Literal("R"))|eol))
parser = (
    Suppress(vbar + (Literal("c")|Literal("C"))) + 
    Word(hexnums, exact=8).setResultsName("hex") + 
    SkipTo(endTag).setResultsName("content") + 
    Suppress(endTag)
).addParseAction(colorize)

result = parser.transformString(text)
new_result = parser.transformString(result)

while(result != new_result):
   result = new_result
   new_result = parser.transformString(result)


print (result)

when text = "|c71d5FFFFI'm saying something in color|cFFFFFFFF then in white |r|r":

output:

<span style="color:#71d5FF;">I'm saying something in color<span style="color:#FFFFFF;"> then in white</span></span>

when text = "|c71d5FFFFI'm saying something in color"

output:

<span style="color:#71d5FF;">I'm saying something in color</span>