[Cuis-dev] question about Compiler evaluate:

[Mark Volkmann]

I should have described more what I’m really after. My app (a GUI for my “method finder”) has a TextModelMorph where the user can enter any Smalltalk expression. I need to evaluate that string to arrive at a Smalltalk object. I was hoping that the Compiler class could give me an error message that describes what is wrong with anything the user enters. Having an expression like ‘1 + x’ where x is an unknown variable is a simple example, but I was hoping to get helpful error messages for any attempt at a Smalltalk expression.

---
R. Mark Volkmann
Object Computing, Inc.

> On Jan 17, 2025, at 12:46 PM, Weslleymberg Lisboa via Cuis-dev <cuis-dev at lists.cuis.st> wrote:
> 
> Hi, Mark
> 
> I found 'is Undeclared' in UndeclaredVariableWarning>>defaultAction which seems to match what you see in the transcript.
> 
> I was able to get rid of the transcript error message by doing:
> 
> expression := '1 + x'.
> [ Compiler evaluate: expression ] on: UndeclaredVariableWarning do: [:ex | ex resume: false] on: Error do: [:ex | ex inspect ]
> 
> To give a little context, I searched for references to the class UndeclaredVariableWarning. One of the results was Encoder>>#undeclared: where the comments mention how to disable the warning.
> 
> Em 17/01/2025 09:40, Mark Volkmann via Cuis-dev escreveu:
>> In a Workspace, if I "Do It" the first expression below and "Print It" the second expression, it prints 3 as expected.
>> expression := '1 + 2'.
>> [ Compiler evaluate: expression ] on: Error do: [ :ex | ex inspect ].
>> Now if I change the 2 in expression to x and repeat, it prints the following:
>> MessageNotUnderstood: UndefinedObject>>adaptToNumber:andSend:
>> It also writes the following to the Transcript:
>> UndefinedObject>>DoIt (x is Undeclared)
>> Looking in the Inspect window I see that none of the instance variables contain "x is Undeclared". I really want to get that string. I've searched the Compiler methods and haven't found a way to do this. Does anyone know how I could access that error message?
>> I'd also like to prevent the error message from being written to the Transcript so I can completely handle it in my code.
>> --
>> R. Mark Volkmann
>> Object Computing, Inc.
> 
> --
> Wéslleymberg Lisboa
> Graduado em Sistemas de Informação
> Docente no IFFluminense - Campus Itaboraí
> 
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