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|
######################################################################
# The remainder of this file is from parsedesc.{g,py}
def append(lst, x):
"Imperative append"
lst.append(x)
return lst
def add_inline_token(tokens, str):
tokens.insert( 0, (str, eval(str, {}, {})) )
return Terminal(str)
def cleanup_choice(lst):
if len(lst) == 0: return Sequence([])
if len(lst) == 1: return lst[0]
return apply(Choice, tuple(lst))
def cleanup_sequence(lst):
if len(lst) == 1: return lst[0]
return apply(Sequence, tuple(lst))
def cleanup_rep(node, rep):
if rep == 'star': return Star(node)
elif rep == 'plus': return Plus(node)
else: return node
def resolve_name(tokens, id, args):
if id in map(lambda x: x[0], tokens):
# It's a token
if args:
print 'Warning: ignoring parameters on TOKEN %s<<%s>>' % (id, args)
return Terminal(id)
else:
# It's a name, so assume it's a nonterminal
return NonTerminal(id, args)
%%
parser ParserDescription:
option: "context-insensitive-scanner"
ignore: "[ \t\r\n]+"
ignore: "#.*?\r?\n"
token END: "$"
token ATTR: "<<.+?>>"
token STMT: "{{.+?}}"
token ID: '[a-zA-Z_][a-zA-Z_0-9]*'
token STR: '[rR]?\'([^\\n\'\\\\]|\\\\.)*\'|[rR]?"([^\\n"\\\\]|\\\\.)*"'
token LP: '\\('
token RP: '\\)'
token LB: '\\['
token RB: '\\]'
token OR: '[|]'
token STAR: '[*]'
token PLUS: '[+]'
token QUEST: '[?]'
token COLON: ':'
rule Parser: "parser" ID ":"
Options
Tokens
Rules<<Tokens>>
END
{{ return Generator(ID,Options,Tokens,Rules) }}
rule Options: {{ opt = {} }}
( "option" ":" Str {{ opt[Str] = 1 }} )*
{{ return opt }}
rule Tokens: {{ tok = [] }}
(
"token" ID ":" Str {{ tok.append( (ID,Str) ) }}
| "ignore" ":" Str {{ tok.append( ('#ignore',Str) ) }}
)*
{{ return tok }}
rule Rules<<tokens>>:
{{ rul = [] }}
(
"rule" ID OptParam ":" ClauseA<<tokens>>
{{ rul.append( (ID,OptParam,ClauseA) ) }}
)*
{{ return rul }}
rule ClauseA<<tokens>>:
ClauseB<<tokens>>
{{ v = [ClauseB] }}
( OR ClauseB<<tokens>> {{ v.append(ClauseB) }} )*
{{ return cleanup_choice(v) }}
rule ClauseB<<tokens>>:
{{ v = [] }}
( ClauseC<<tokens>> {{ v.append(ClauseC) }} )*
{{ return cleanup_sequence(v) }}
rule ClauseC<<tokens>>:
ClauseD<<tokens>>
( PLUS {{ return Plus(ClauseD) }}
| STAR {{ return Star(ClauseD) }}
| {{ return ClauseD }} )
rule ClauseD<<tokens>>:
STR {{ t = (STR, eval(STR,{},{})) }}
{{ if t not in tokens: tokens.insert( 0, t ) }}
{{ return Terminal(STR) }}
| ID OptParam {{ return resolve_name(tokens, ID, OptParam) }}
| LP ClauseA<<tokens>> RP {{ return ClauseA }}
| LB ClauseA<<tokens>> RB {{ return Option(ClauseA) }}
| STMT {{ return Eval(STMT[2:-2]) }}
rule OptParam: [ ATTR {{ return ATTR[2:-2] }} ] {{ return '' }}
rule Str: STR {{ return eval(STR,{},{}) }}
%%
# This replaces the default main routine
yapps_options = [
('context-insensitive-scanner', 'context-insensitive-scanner',
'Scan all tokens (see docs)')
]
def generate(inputfilename, outputfilename='', dump=0, **flags):
"""Generate a grammar, given an input filename (X.g)
and an output filename (defaulting to X.py)."""
if not outputfilename:
if inputfilename[-2:]=='.g': outputfilename = inputfilename[:-2]+'.py'
else: raise "Invalid Filename", outputfilename
print 'Input Grammar:', inputfilename
print 'Output File:', outputfilename
DIVIDER = '\n%%\n' # This pattern separates the pre/post parsers
preparser, postparser = None, None # Code before and after the parser desc
# Read the entire file
s = open(inputfilename,'r').read()
# See if there's a separation between the pre-parser and parser
f = find(s, DIVIDER)
if f >= 0: preparser, s = s[:f]+'\n\n', s[f+len(DIVIDER):]
# See if there's a separation between the parser and post-parser
f = find(s, DIVIDER)
if f >= 0: s, postparser = s[:f], '\n\n'+s[f+len(DIVIDER):]
# Create the parser and scanner
p = ParserDescription(ParserDescriptionScanner(s))
if not p: return
# Now parse the file
t = wrap_error_reporter(p, 'Parser')
if not t: return # Error
if preparser is not None: t.preparser = preparser
if postparser is not None: t.postparser = postparser
# Check the options
for f in t.options.keys():
for opt,_,_ in yapps_options:
if f == opt: break
else:
print 'Warning: unrecognized option', f
# Add command line options to the set
for f in flags.keys(): t.options[f] = flags[f]
# Generate the output
if dump:
t.dump_information()
else:
t.output = open(outputfilename, 'w')
t.generate_output()
if __name__=='__main__':
import sys, getopt
optlist, args = getopt.getopt(sys.argv[1:], 'f:', ['dump'])
if not args or len(args) > 2:
print 'Usage:'
print ' python', sys.argv[0], '[flags] input.g [output.py]'
print 'Flags:'
print (' --dump' + ' '*40)[:35] + 'Dump out grammar information'
for flag, _, doc in yapps_options:
print (' -f' + flag + ' '*40)[:35] + doc
else:
# Read in the options and create a list of flags
flags = {}
for opt in optlist:
for flag, name, _ in yapps_options:
if opt == ('-f', flag):
flags[name] = 1
break
else:
if opt == ('--dump', ''):
flags['dump'] = 1
else:
print 'Warning - unrecognized option: ', opt[0], opt[1]
apply(generate, tuple(args), flags)
|
