1 "{ Package: 'stx:goodies/petitparser/compiler' }"

     2 

     3 "{ NameSpace: Smalltalk }"

     4 

     5 PPCNodeVisitor subclass:#PPCFSAVisitor

     6 	instanceVariableNames:'fsaCache idGen'

     7 	classVariableNames:''

     8 	poolDictionaries:''

     9 	category:'PetitCompiler-Visitors'

    10 !

    11 

    12 !PPCFSAVisitor methodsFor:'accessing'!

    13 

    14 idGen: anObject

    15     idGen := anObject

    16 ! !

    17 

    18 !PPCFSAVisitor methodsFor:'as yet unclassified'!

    19 

    20 unorderedChoiceFromFollowSet: followSet

    21     | followFsas  |

    22     

    23     ^ fsaCache at: followSet ifAbsentPut: [ 

    24         followFsas := followSet collect: [ :followNode | 

    25             followNode asFsa 

    26                 name: (idGen idFor: followNode);

    27                 retval: (idGen idFor: followNode); 

    28                 yourself

    29         ].

    30         self unorderedChoiceFromFsas: followFsas.

    31     ]

    32      

    33 !

    34 

    35 unorderedChoiceFromFsas: fsas

    36     | result startState |

    37     result := PEGFsa new.

    38     startState := PEGFsaState new.

    39     

    40     result addState: startState.

    41     result startState: startState.

    42 

    43     fsas do: [ :fsa | 

    44         result adopt: fsa.

    45         result addTransitionFrom: startState to: fsa startState.

    46     ].

    47 

    48     result determinizeStandard.

    49     ^ result

    50 !

    51 

    52 visitToken: tokenNode

    53     | anFsa |

    54 

    55     anFsa := tokenNode asFsa determinize.

    56     anFsa name: (idGen idFor: tokenNode).

    57     anFsa retval: (idGen idFor: tokenNode).

    58     

    59     tokenNode fsa: anFsa.

    60     ^ tokenNode

    61 !

    62 

    63 visitTokenConsumeNode: node

    64     | epsilon anFsa followSet |

    65     followSet := node followSetWithTokens.

    66     

    67     epsilon := followSet anySatisfy: [ :e | e acceptsEpsilon ].

    68     followSet := followSet reject: [ :e | e acceptsEpsilon ].

    69     epsilon ifTrue: [ followSet add: PPCEndOfFileNode instance ].

    70     

    71     anFsa := self unorderedChoiceFromFollowSet: followSet.

    72     anFsa name: 'nextToken_', (idGen idFor: node).

    73 

    74     node nextFsa: anFsa.

    75 !

    76 

    77 visitTokenNode: node

    78     ^ self visitToken: node

    79 !

    80 

    81 visitTokenizingParserNode: node

    82     "TODO JK: hack alert, change the handling of WS!!"

    83     self visitWhitespace: node whitespace.

    84 

    85     self visit: node tokens.

    86     self visit: node parser.

    87     ^ node

    88 !

    89 

    90 visitTrimmingTokenNode: node

    91     ^ self visitToken: node

    92 !

    93 

    94 visitWhitespace: node

    95     "JK HACK: treat ws as token -> create FSA for whitespace"

    96     | retval |

    97     retval := self visitToken: node.

    98     "we don't care about the finals of whitespace"

    99     node fsa removeFinals.

   100     ^ retval

   101 ! !

   102 

   103 !PPCFSAVisitor methodsFor:'initialization'!

   104 

   105 initialize

   106     super initialize.

   107     

   108     "for the given set of nodes, remember the unordered choice fsa

   109         see `unorderedChoiceFromFollowSet:`

   110     "

   111     fsaCache := Dictionary new.

   112 ! !

   113