Hi Tim,

On Thu, 11 Feb 2021, gettimothy via Squeak-dev wrote:

> Hi Folks,
> 
> I am importing my grammar/xtreams parsing work into its own image so that I can change my system fonts without making my other projects look funky with the chages.
> 
> The base image is:
> 
> 
> Image
> -----
> /home/wm/usr/src/smalltalk/squeak6.0alpha/shared/Squeak6.0alpha-19802-64bit.image
> Squeak6.0alpha
> latest update: #20147
> 
> to the latest:
> 
> /home/wm/Squeak/images/WikitextParser/WikitextParser.image
> Squeak6.0alpha
> latest update: #20188
> 
> During the import of my work, I ran into this issue regarding Store Into in a block:
> 
> 
> http://forum.world.st/Cuis-problem-with-blocks-td1047783.html#a1049556
> 
> 
> The parser is looking for patterns of  (10e2)e2....i.e.  exponential notation of unknown length, i.e. per the comment on Collection inject: into:  accumulate a running value...
> 
> 
> 
> Per the email chain referenced, the "Allow block argument assignment" is allowed in the former, and not allowed in the latest, which is cool with me, but...
> 
> My question is "what is the generic form" that I can use to duplicate the behaviour I want?
> Here is the original method with the bad store into:
>       Float: first exponent: pairs
>   <action: 'Float' arguments:#(1 2)>
> 
> "Float <- ( Number / Group / Function ) (''e'' ( Number / Group / Function ))+"
> 
> |result|
>   result := pairs inject: first
>                         into: [ :base  :pair |
>                                     (pair first = 'e')
>                                                ifTrue: [
>                                                             (pair last abs > 1)
>                                                                   ifTrue:[ base := Float readFrom: ((base asString) , 'e', (pair last asString))]
>                                                                   ifFalse:[ base := (base * (10 raisedTo:(pair last) ))]]].

That makes no sense. I can't even fathom how it works.
#inject:into:'s second argument, the block, must return the computed 
value.
Currently that block returns the value assigned to base when pair first = 
'e' and nil otherwise.
So, if it works correctly now, which is doubtful, then just remove the 
assignments to base from the block and it should just work.

> 
> transcripton ifTrue:[Transcript show:'Float ' , (result asFloat); cr. ].
> 
> 
> ^ result asFloat
> 
> 
> 
> 
> Here is my "hack" to fix it , (I create a tmp variable outside the block to use in place of the "base"):
> 
>
>       Float: first exponent: pairs
>   <action: 'Float' arguments:#(1 2)>
> 
> "Float <- ( Number / Group / Function ) (''e'' ( Number / Group / Function ))+"
> 
> |result tmp|
>         result := pairs inject: first
>                               into: [ :base  :pair |
>                                           (pair first = 'e')
>                                                 ifTrue: [
>                                                       (pair last abs > 1)
>                                                             ifTrue:[tmp := base.
>                                                                         tmp := Float readFrom: ((tmp asString) , 'e', (pair last asString))]
>                                                                         tmp := Float readFrom: ((tmp asString) , 'e', (pair last asString)).
>                                                                         tmp]
>                                                             ifFalse:[tmp := base.
>                                                                         tmp := (tmp * (10 raisedTo:(pair last) ))]]].
>                                                                         tmp := (tmp * (10 raisedTo:(pair last) )).
>                                                                         tmp]]].

Those parentheses don't look well balanced, but anyway, there's no need 
to use tmp, especially not one at the outer scope.


Levente

> 
> transcripton ifTrue:[Transcript show:'Float ' , (result asFloat); cr. ].
> 
> 
> ^ result asFloat
> 
> 
> I got a bad feeling about this one.
> 
> 
> Is there a general form for this ?
> 
> 
> My brain is a bit foggy from working the graveyard shift so what would be obvious while in normal conditions , is not obvious today.
> 
> 
> Thanks for you time.
> 
> 
> 
> 
>