"{ Package: 'jv:libgdbs' }"

Object subclass:#GDBMIParser

	instanceVariableNames:'source lookahead'

	classVariableNames:''

	poolDictionaries:''

	category:'GDB-Private-MI'

!

!GDBMIParser class methodsFor:'instance creation'!

on: aStringOrStream 

    ^ self new on: aStringOrStream

    "Created: / 27-05-2014 / 23:50:01 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!GDBMIParser methodsFor:'initialization'!

on: aStringOrStream

    source := aStringOrStream readStream

    "Created: / 27-05-2014 / 23:50:24 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!GDBMIParser methodsFor:'parsing'!

parseCString

    | buffer inString nextChar |

    self expect: $".

    nextChar := self next.

    buffer := (String new: 50) writeStream.

    inString := true.

    [inString] whileTrue:[

        nextChar isNil ifTrue:[

            self error: 'Unexpected end of input'.

        ].

        nextChar == $\ ifTrue:[

            nextChar := self next.

            nextChar := self parseCStringEscape:nextChar.

        ] ifFalse:[

            (nextChar == $") ifTrue:[

                (self peekOrNil == $") ifTrue:[

                    self next

                ] ifFalse:[

                    inString := false

                ]

            ].

        ].

        inString ifTrue:[

            buffer nextPut:nextChar.

            nextChar := self next

        ]

    ].

    ^ buffer contents

    "Created: / 27-05-2014 / 23:51:35 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

parseCStringEscape: char

    |ascii c |

    char == $" ifTrue:[

        ^ $".

    ].

    char == $b ifTrue:[

        ^ Character backspace

    ].

    char == $t ifTrue:[

        ^ Character tab

    ].

    char == $n ifTrue:[

        ^ Character cr

    ].

    char == $r ifTrue:[

        ^ Character return

    ].

    char == $f ifTrue:[

        ^ Character newPage

    ].

"/    char == $u ifTrue:[

"/        ascii := 0.

"/        c := source peekOrNil.

"/        4 timesRepeat:[

"/            (c isDigitRadix:16) ifFalse:[

"/                self syntaxError:'invalid hex character constant'

"/                        position:source position-2 to:(source position - 1).

"/                ^ Character value:ascii

"/            ].

"/            ascii := (ascii bitShift:4).

"/            ascii := ascii + c digitValue.

"/            source next. c := source peekOrNil.

"/        ].

"/        ^ Character value:ascii

"/    ].

    char == $x ifTrue:[

        ascii := 0.

        c := self peekOrNil.

        2 timesRepeat:[

            (c isDigitRadix:16) ifFalse:[

                self error:'Invalid hex character escape'.

                ^ Character value:ascii

            ].

            ascii := (ascii bitShift:4).

            ascii := ascii + c digitValue.

            self next. c := self peekOrNil.

        ].

        ^ Character value:ascii

    ].

    "OctalEscape ::= \ OctalDigit |

                     \ OctalDigit OctalDigit

                     \ ZeroToThree OctalDigit OctalDigit"

    (char between:$0 and:$3) ifTrue:[

        ascii := char digitValue.

        c := self peekOrNil.

        (c between: $0 and: $7) ifTrue:[

            self next.

            ascii := (ascii bitShift:3).

            ascii := ascii + c digitValue.

        ].

        c := self peekOrNil.

        (c between: $0 and: $7) ifTrue:[

            self next.

            ascii := (ascii bitShift:3).

            ascii := ascii + c digitValue.

        ].

        ^ Character value:ascii

    ].

    (char between:$4 and: $7) ifTrue:[

        ascii := char digitValue.            

        c := self peekOrNil.

        (c between: $0 and: $7) ifTrue:[

            self next.

            ascii := (ascii bitShift:3).

            ascii := ascii + c digitValue.

        ].

        ^ Character value:ascii

    ].

    ^ char

    "Created: / 28-05-2014 / 00:02:40 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

parseToken

    "Created: / 28-05-2014 / 00:14:57 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!GDBMIParser methodsFor:'parsing-utils'!

expect: aStringOrChar

    | c |

    aStringOrChar isCharacter ifTrue:[

        (self atEnd or:[(c := self next) ~= aStringOrChar]) ifTrue:[

            self error:('Expected ''%1'' got ''%2''.' bindWith: aStringOrChar with: c).

        ].

        ^self.

    ].

    aStringOrChar isString ifTrue:[

        aStringOrChar do:[:expected|

            (self atEnd or:[(c := self next) ~= expected]) ifTrue:[

                self error:('Expected ''%1''.' bindWith: aStringOrChar).

            ].

        ].

        ^self.

    ].

    self error:'Invalid expected value'.

    "Created: / 19-11-2012 / 20:08:33 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 28-05-2014 / 00:17:06 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

expectLineEnd

    self expect: Character cr.

    "Created: / 19-11-2012 / 20:06:21 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

expectSpace

    self expect: Character space.

    "Created: / 19-11-2012 / 20:06:27 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!GDBMIParser methodsFor:'streaming'!

atEnd

    ^ source atEnd

    "Created: / 28-05-2014 / 00:17:06 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

next

    | next |

    lookahead notNil ifTrue:[ 

        next := lookahead.

        lookahead := nil.

        ^ next.

    ].

    ^ source next.

    "Created: / 23-10-2012 / 10:57:24 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 28-05-2014 / 00:23:33 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

nextLine

    lookahead := nil.

    ^source nextLine

    "Created: / 23-10-2012 / 11:05:47 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 28-05-2014 / 00:21:12 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

peek

    lookahead notNil ifTrue:[ 

        ^ lookahead

    ].

    ^ lookahead := source next.

    "Created: / 28-05-2014 / 00:18:32 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

peekOrNil

    lookahead notNil ifTrue:[ ^ lookahead ].

    source atEnd ifTrue:[ ^ nil ].

    ^ self peek

    "Created: / 28-05-2014 / 00:15:32 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

skipSeparators

    lookahead := nil.

    source skipSeparators

    "Created: / 19-11-2012 / 20:05:04 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 28-05-2014 / 00:21:17 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !