"
 COPYRIGHT (c) 1989 by Claus Gittinger
	      All Rights Reserved

 This software is furnished under a license and may be used
 only in accordance with the terms of that license and with the
 inclusion of the above copyright notice.   This software may not
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
"
"{ Package: 'stx:libcomp' }"

ParseNode subclass:#StatementNode
	instanceVariableNames:'expression nextStatement lineNr'
	classVariableNames:''
	poolDictionaries:''
	category:'System-Compiler-Support'
!

!StatementNode class methodsFor:'documentation'!

copyright
"
 COPYRIGHT (c) 1989 by Claus Gittinger
	      All Rights Reserved

 This software is furnished under a license and may be used
 only in accordance with the terms of that license and with the
 inclusion of the above copyright notice.   This software may not
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
"
!

documentation
"
    node for parse-trees, representing statements
    This is a helper class for the compiler.

    [author:]
        Claus Gittinger
"
! !

!StatementNode class methodsFor:'instance creation'!

expression:e
    ^ (self basicNew) expression:e
! !

!StatementNode methodsFor:'accessing'!

expression
    ^ expression
!

expression:e
    expression := e
!

last
    "return the last statement in a list"

    |last this|

    "this could be done more elegant - but with lots of recursion"
    last := self.
    this := self.
    [this notNil] whileTrue:[
	last := this.
	this := this nextStatement
    ].
    ^ last
!

lineNumber
    "return lineNr"

    lineNr notNil ifTrue:[^ lineNr].
    expression notNil ifTrue:[ ^ expression lineNumber ].
    nextStatement notNil ifTrue:[^ nextStatement lineNumber].
    ^ nil

    "Created: / 14.5.1998 / 19:31:06 / cg"
!

lineNumber:something
    "set lineNr"

    lineNr := something.

    "Created: / 14.5.1998 / 19:31:11 / cg"
!

lineNumberOfFirstMessage
    |lno|

    lno := self lineNumber.
    self messagesDo:[:m | lno := lno min:(m lineNumber)].
    ^ lno
!

nextStatement
    ^ nextStatement
!

nextStatement:s
    nextStatement := s
! !

!StatementNode methodsFor:'code generation'!

codeAllForSideEffectOn:aStream inBlock:b for:aCompiler
    |thisStatement|

    thisStatement := self.
    [thisStatement notNil] whileTrue:[
        thisStatement codeForSideEffectOn:aStream inBlock:b for:aCompiler.
        thisStatement := thisStatement nextStatement
    ].
!

codeForSideEffectOn:aStream inBlock:b for:aCompiler
    "generate code for this statement - value not needed"

    expression notNil ifTrue:[
        expression codeForSideEffectOn:aStream inBlock:b for:aCompiler
    ]
!

codeOn:aStream inBlock:b for:aCompiler
    "generate code for this statement"

    expression notNil ifTrue:[
        expression codeOn:aStream inBlock:b for:aCompiler
    ]
! !

!StatementNode methodsFor:'converting'!

asCollectionOfStatements
    "returns a orderedCollection of statements,
     representing the list of which the receiver is the head"

    |coll stat|

    coll := OrderedCollection new.
    stat := self.
    [stat notNil] whileTrue:[
        coll add:stat.
        stat := stat nextStatement.
    ].
    ^ coll
! !

!StatementNode methodsFor:'enumerating'!

messagesDo:aBlock
    |s e|

    s := self.
    [s notNil] whileTrue:[
        e := s expression.
        e notNil ifTrue:[e messagesDo:aBlock].
        s := s nextStatement
    ].
!

nodeDo:anEnumerator
    "helper for parse tree walking"

    |stats this expr|

    "/ too stupid: ST/X statements are linked as a list ...

    stats := OrderedCollection new.
    this := self.
    [this notNil] whileTrue:[
        this isReturnNode ifTrue:[
            stats add:this
        ] ifFalse:[
            expr := this expression.
            stats add:(expr ? this).
        ].
        this := this nextStatement
    ].
    ^ anEnumerator doSequence:self temporaries:#() statements:stats

    "Created: 19.6.1997 / 16:45:34 / cg"
    "Modified: 19.6.1997 / 17:06:47 / cg"
! !

!StatementNode methodsFor:'evaluation'!

evaluateAllIn:anEnvironment
    |lastValue thisStatement|

    "this could be done more elegant - but with lots of recursion"
    thisStatement := self.
    [thisStatement notNil] whileTrue:[
        lastValue := thisStatement evaluateExpressionIn:anEnvironment.
        thisStatement := thisStatement nextStatement
    ].
    ^ lastValue
!

evaluateExpressionIn:anEnvironment
    ^ expression evaluateIn:anEnvironment
!

evaluateIn:anEnvironment
    ^ self evaluateAllIn:anEnvironment.
! !

!StatementNode methodsFor:'printing & storing'!

printAllOn:aStream 
    self printAllOn:aStream indent:4
!

printAllOn:aStream indent:i
    |thisStatement|

    thisStatement := self.
    [thisStatement notNil] whileTrue:[
        aStream spaces:i.
        thisStatement printOn:aStream indent:i.
        thisStatement nextStatement notNil ifTrue:[
            aStream nextPut:$..
            aStream cr.
        ].
        thisStatement := thisStatement nextStatement
    ]
!

printOn:aStream indent:i
    expression printOn:aStream indent:i.
! !

!StatementNode methodsFor:'queries'!

collectBlocksInto:aCollection
    |this ex|

    this := self.
    [this notNil] whileTrue:[
        ex := this expression.
        ex notNil ifTrue:[
            ex collectBlocksInto:aCollection.
        ].
        this := this nextStatement
    ].

    "Created: 23.10.1996 / 15:44:13 / cg"
    "Modified: 20.4.1997 / 12:10:18 / cg"
!

isSimpleConstant
    nextStatement notNil ifTrue:[^ false].
    ^ expression isConstant
!

isSimpleExpression
    nextStatement notNil ifTrue:[^ false].
    ^ expression notNil
!

isSimpleVariable
    nextStatement notNil ifTrue:[^ false].
    ^ expression isVariable
!

listEndsWithReturn
    |thisStatement lastStatement|

    thisStatement := self.
    [thisStatement notNil] whileTrue:[
        lastStatement := thisStatement.
        thisStatement := thisStatement nextStatement
    ].

    ^ lastStatement isReturnNode

    "Created: 19.8.1996 / 14:32:47 / cg"
! !

!StatementNode class methodsFor:'documentation'!

version
    ^ '$Header: /cvs/stx/stx/libcomp/StatementNode.st,v 1.35 2008-07-25 12:45:46 cg Exp $'
! !