def ruleGrammar():
''' function to generate a grammar for parsing grammar rules
'''
LexD = kjParser.LexDictionary()
# use SQL/Ansi style comments
LexD.comment( COMMENTFORM )
# declare keywords
RStart = LexD.keyword( RSKEY )
TwoColons = LexD.keyword( COLKEY )
LeadsTo = LexD.keyword( LTKEY )
# declare terminals
ident = LexD.terminal(IDNAME, IDFORM, IdentFun )
# declare nonterminals
Root = kjParser.nonterminal("Root")
Rulelist = kjParser.nonterminal("RuleList")
Rule = kjParser.nonterminal("Rule")
RuleName = kjParser.nonterminal("RuleName")
NonTerm = kjParser.nonterminal("NonTerm")
Body = kjParser.nonterminal("Body")
# declare rules
# Root >> NonTerm :: Rulelist
InitRule = kjParser.ParseRule( Root, \
[NonTerm, TwoColons, Rulelist], RootReduction )
# Rulelist >>
RLNull = kjParser.ParseRule( Rulelist, [], NullRuleList)
# Rulelist >> Rule Rulelist
RLFull = kjParser.ParseRule( Rulelist, [Rule,Rulelist], FullRuleList)
# Rule >> "@R :: NonTerm >> Body
RuleR = kjParser.ParseRule( Rule, \
[RStart, RuleName, TwoColons, NonTerm, LeadsTo, Body],\
InterpRule)
# Rulename >> ident
RuleNameR = kjParser.ParseRule( RuleName, [ident], InterpRuleName)
# NonTerm >> ident
NonTermR = kjParser.ParseRule( NonTerm, [ident], InterpNonTerm)
# Body >>
BodyNull = kjParser.ParseRule( Body, [], NullBody)
# Body >> ident Body
BodyFull = kjParser.ParseRule( Body, [ident,Body], FullBody)
# declare Rules list and Associated Name dictionary
Rules = [RLNull, RLFull, RuleR, RuleNameR, NonTermR,\
BodyNull, BodyFull, InitRule]
RuleDict = \
{ "RLNull":0, "RLFull":1, "RuleR":2, "RuleNameR":3, \
"NonTermR":4, "BodyNull":5, "BodyFull":6 , "InitRule":7 }
# make the RuleSet and compute the associate DFA
RuleSet = Ruleset( Root, Rules )
RuleSet.DoSLRGeneration()
# construct the Grammar object
Result = kjParser.Grammar( LexD, RuleSet.DFA, Rules, RuleDict )
return Result
BigList[4] = self.MaxStates
BigList[5] = self.reducts
BigList[6] = self.moveTos
BigList[7] = self.Root
BigList[8] = self.CaseSensitivity
# dump the big list to the file
marshal.dump( BigList, self.File )
#end class
#######################testing stuff
if RUNTESTS:
def echo(x): return x
# simple grammar stolen from a text
LD0 = kjParser.LexDictionary()
id = LD0.terminal("id","id",echo)
plus = LD0.punctuation("+")
star = LD0.punctuation("*")
oppar = LD0.punctuation("(")
clpar = LD0.punctuation(")")
equals = LD0.punctuation("=")
E = kjParser.nonterminal("E")
T = kjParser.nonterminal("T")
Tp = kjParser.nonterminal("Tp")
Ep = kjParser.nonterminal("Ep")
F = kjParser.nonterminal("F")
rule1 = kjParser.ParseRule( E, [ T, Ep ] )
rule2 = kjParser.ParseRule( Ep, [ plus, T, Ep ] )
rule3 = kjParser.ParseRule( Ep, [ ] )
rule4 = kjParser.ParseRule( T, [ F, Tp ] )