[squeak-dev] Re: funky Compiler implementation

Nicolas Cellier nicolas.cellier.aka.nice at gmail.com
Thu Feb 25 02:28:21 UTC 2010

2010/2/25 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
> Try:
> Compiler evaluate: '0r0 + 1'.
> Then:
> Compiler evaluate: '1 + 0r0'.
> and explain the difference...
> ...
> It lies in initialization, the first token being scanned before the
> encoder is set properly...
> No encoder, no class information easily accessible, no
> SyntaxErrorNotification issued...
> So the first returns nil...
> Nicolas

 I could attempt to change this one:

parse: sourceStream class: class category: aCategory noPattern:
noPattern context: ctxt notifying: req ifFail: aBlock
	"Answer a MethodNode for the argument, sourceStream, that is the root of
	 a parse tree. Parsing is done with respect to the argument, class, to find
	 instance, class, and pool variables; and with respect to the argument,
	 ctxt, to find temporary variables. Errors in parsing are reported to the
	 argument, req, if not nil; otherwise aBlock is evaluated. The argument
	 noPattern is a Boolean that is true if the the sourceStream does not
	 contain a method header (i.e., for DoIts)."

	| methNode repeatNeeded myStream s p |
	category := aCategory.
	myStream := sourceStream.
	[repeatNeeded := false.
	 p := myStream position.
	 s := myStream upToEnd.
	 myStream position: p.
+	 self encoder init: class context: ctxt notifying: self.
	 self init: myStream notifying: req failBlock: [^ aBlock value].
	 doitFlag := noPattern.
	 failBlock:= aBlock.
	 [methNode := self
					method: noPattern
					context: ctxt
-					encoder: (self encoder init: class context: ctxt notifying: self)]
+					encoder: self encoder]
		on: ReparseAfterSourceEditing
		do:	[ :ex |
			repeatNeeded := true.
			myStream := ReadStream on: requestor text string].
! 			But there is a minor problem here ^^^^^^^^^^^^^^^^^^^
	 repeatNeeded] whileTrue:
		[encoder := self encoder class new].
	methNode sourceText: s.

The problem is if I select some partial code to evaluate in a Debugger
or a Workspace:

| a b |
^(a := 1) + a

And that I remove b, then the whole text is compiled instead of just
my selection...
I find all these workarounds like requestorOffset and the like very fragile...


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