rspivak / lsbasi Goto Github PK

Thank you so much for making your Let's build a simple interpreter series, it's really helping me learn how interpreters work while I'm making my own programming language in JavaScript 😄

In spi.py (https://github.com/rspivak/lsbasi/blob/master/part15/spi.py), the skip_comment() function (starts on line 172) does not properly handle input source that contains an un-terminated comment.

For example, when run on the input below, spi.py hangs:

PROGRAM Test;
VAR
a : INTEGER;
BEGIN
a := 10 * 25; { Un-terminated comment. FREEZE!
END.

Hi,
This is mine :

https://github.com/pejman-hkh/4php

I want to make a compiler for a c++ like language and I want to know how I can change PROCEDURE to functions?

Hello sir~

I love this series post, It's a great tutorial, so, When is the next post coming out？

It currently reads """proccall_statement : ID LPAREN expr? (COMMA expr)* RPAREN"""
I believe the correct version is """proccall_statement : ID LPAREN (expr (COMMA expr)*)? RPAREN""", because otherwise foobar(, b, c) would be valid.

If I'm right, then the only additional change is that the while loop

Hello,

I'm currently going through your tutorial on "Lets build a simple interpreter".
I enjoy reading the tutorial, but I don't really understand why the change in Symbol and SymbolTable from chapter 11 to chapter 13, where much of what we already have defined, you want us to redefine?

Also I encountered, something I don't really understand with the VarSymbol scope property...

I fail to see where VarSymbol.scope.scope_level is defined,

This is from the https://github.com/rspivak/lsbasi/blob/master/part14/src2srccompiler.py#L171

        var_name = node.value
        var_symbol = self.current_scope.lookup(var_name)
        if var_symbol is None:
            raise Exception(
                "Error: Symbol(identifier) not found '%s'" % var_name
            )
        scope_level = str(var_symbol.scope.scope_level)
        return '<%s:%s>' % (var_name + scope_level, var_symbol.type.name)

and roaming around in your spi.py, I cannot find the link to .scope is it possible for you to help me out?

Thanks in advance

I've tried to generate AST in part18 using genastdot.py, but it raised AttributeError: 'ProcedureDecl' object has no attribute 'params'.
This can be fixed by altering self.formal_params on self.params in ProcedureDecl class.

Given the fantastic work you've done so far, its a real shame to leave it hanging, the work with nested scopes is fantastic and brilliantly explained.

A great topic for the next instalment might be IF blocks with their own scopes

From there you only need some rudimentary input / output and you have a much more complete set of articles...

I am trying to make an interpreter of Swarm programing language. If you have some ideas or advices, please contact me.

Here is the repo link.

github.com/ME-Msc/Swarm

github.com/ME-Msc/Swarm-Interpreter

As you metioned in the articles!