/
antlrstrip.py
executable file
·42 lines (38 loc) · 1.21 KB
/
antlrstrip.py
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#!/usr/bin/python
import sys
import re
p0 = re.compile('options [{][^}]*[}]')
p5 = re.compile('\'}\'')
p4 = re.compile('tokens [{][^}]*[}]')
p1 = re.compile('[{][^}]*[}]')
p2 = re.compile('[@][a-z]*')
p3 = re.compile('returns [\[][^\]]*[\]]')
p6 = re.compile('/[*]([^*]|[*][^/])*[*]/')
p4 = re.compile('tokens [{][^}]*[}]')
def main():
if (len(sys.argv)!=3):
print "Usage: antlrstrip.py Grammar.g Grammar_pure.g"
return
inf = open(sys.argv[1],"r")
out = open(sys.argv[2],'w')
# reading the grammar
lines = ' '.join(inf.readlines())
# regexp-powered cleaning
lines = p6.sub('',lines) # kill comments
lines = p5.sub('',lines) # kill '}'s
lines = p1.sub('',lines) # kill semantic actions
lines = p2.sub('',lines) # kill modifiers
lines = p3.sub('',lines) # kill returns
lines = p0.sub('',lines) # kill options
lines = p4.sub('',lines) # kill tokens
# whitespace shrinking
lines = ' '.join(lines.split())
# removing terminal symbols, pretty-printing the rest
lines = map(lambda x:(not x.split(':')[0].strip().isupper())*x,lines.split(';'))
while (not lines[-2].strip()): lines.pop()
# writing the pretty-printed result
out.writelines(';\n'.join(lines))
inf.close()
out.close()
if __name__ == "__main__":
main()