"""VRML97-compliant Parser
This example is a full VRML97 parser, originally created
for the mcf.vrml VRML-processing system. It supports all
VRML97 constructs, and should be correct for any VRML97
content you can produce. The parser is fairly fast
(parsing around 280,000 cps on a 1GHz Athlon machine).
This is the errorOnFail version of the grammar, otherwise
identical to the vrml.py module. Note: there is basically
no speed penalty for the errorOnFail version compared to
the original version, as the errorOnFail code is not touched
unless a syntax error is actually found in the input text.
"""
from simpleparse.parser import Parser
from simpleparse.common import chartypes
#print file
VRMLPARSERDEF = r'''header := -[\n]*
vrmlFile := header, vrmlScene, EOF
rootItem := ts,(Proto/ExternProto/ROUTE/('USE',ts,USE,ts)/Script/Node),ts
vrmlScene := rootItem*
Proto := 'PROTO',ts,!, nodegi,ts,'[',ts,(fieldDecl/eventDecl)*,']', ts, '{', ts, vrmlScene,ts, '}', ts
fieldDecl := fieldExposure,ts,!,dataType,ts,name,ts,Field,ts
fieldExposure := 'field'/'exposedField'
dataType := 'SFBool'/'SFString'/'SFFloat'/'SFTime'/'SFVec3f'/'SFVec2f'/'SFRotation'/'SFInt32'/'SFImage'/'SFColor'/'SFNode'/'MFBool'/'MFString'/'MFFloat'/'MFTime'/'MFVec3f'/'MFVec2f'/'MFRotation'/'MFInt32'/'MFColor'/'MFNode'
eventDecl := eventDirection, ts, !,dataType, ts, name, ts
eventDirection := 'eventIn'/'eventOut'
ExternProto := 'EXTERNPROTO',ts,!,nodegi,ts,'[',ts,(extFieldDecl/eventDecl)*,']', ts, ExtProtoURL
extFieldDecl := fieldExposure,ts,!,dataType,ts,name,ts
ExtProtoURL := '['?,(ts,SFString)*, ts, ']'?, ts # just an MFString by another name :)
ROUTE := 'ROUTE',ts, !,name,'.',name, ts, 'TO', ts, name,'.',name, ts
Node := ('DEF',ts,!,name,ts)?,nodegi,ts,'{',ts,(Proto/ExternProto/ROUTE/Attr)*,ts,!,'}', ts
Script := ('DEF',ts,!,name,ts)?,'Script',ts,!,'{',ts,(ScriptFieldDecl/ScriptEventDecl/Proto/ExternProto/ROUTE/Attr)*,ts,'}', ts
ScriptEventDecl := eventDirection, ts, !,dataType, ts, name, ts, ('IS', ts,!, IS,ts)?
ScriptFieldDecl := fieldExposure,ts,!,dataType,ts,name,ts,(('IS', ts,!,IS,ts)/Field),ts
SFNull := 'NULL', ts
# should really have an optimised way of declaring a different reporting name for the same production...
USE := name
IS := name
nodegi := name
Attr := name, ts, (('IS', ts,IS,ts)/Field), ts
Field := ( '[',ts,((SFNumber/SFBool/SFString/('USE',ts,USE,ts)/Script/Node),ts)*, ']'!, ts )/((SFNumber/SFBool/SFNull/SFString/('USE',ts,USE,ts)/Script/Node),ts)+
name := -[][0-9{}\000-\020"'#,.\\ ], -[][{}\000-\020"'#,.\\ ]*
SFNumber := [-+]*, ( ('0',[xX],[0-9]+) / ([0-9.]+,([eE],[-+0-9.]+)?))
SFBool := 'TRUE'/'FALSE'
SFString := '"',(CHARNODBLQUOTE/ESCAPEDCHAR/SIMPLEBACKSLASH)*,'"'!
CHARNODBLQUOTE := -[\134"]+
SIMPLEBACKSLASH := '\134'
ESCAPEDCHAR := '\\"'/'\134\134'
<ts> := ( [ \011-\015,]+ / ('#',-'\012'*,'\n')+ )*
'''
def buildVRMLParser( declaration = VRMLPARSERDEF ):
return Parser( declaration, "vrmlFile" )
if __name__ == "__main__":
import os, sys, time
parser = buildVRMLParser()
if sys.argv[1:]:
filename = sys.argv[1]
data = open(filename).read()
t = time.time()
success, tags, next = parser.parse( data)
d = time.time()-t
print "parsed %s characters of %s in %s seconds (%scps)"%( next, len(data), d, next/(d or 0.000000001) )
# now show the error-generation
print '''About to parse badly formatted VRML data'''
badData = [
'''#whatever\nX{ { } }''',
'''#whatever\nX{ S }''',
'''#whatever\nPROTO ]{ S }''',
'''#whatever\nPROTO []{ S ''',
'''#whatever\nPROTO R [
field SFBool A
]{ }''',
'''#whatever\nPROTO R [
field SFBool
]{ }''',
'''#whatever\nPROTO R [
field SFBool A "
]{ ''',
]
for bad in badData:
try:
parser.parse( bad )
print """\nWARNING: didn't get a syntax error for item %s\n"""%(repr(bad))
except SyntaxError, err:
print err
|