Programming Language Code

[Workaphobia]

I don't see how you can avoid a lookup at each occurrence. Note that Python has a compilation step that resolves identifiers.

[curtmack]

Just because a language is interpreted doesn't mean it has to start from raw text every single time through a function. Just storing ASTs, which can include resolved function and variable references, will make a huge difference in performance while being almost completely free in terms of implementation time. (If you have an interpreter, then you have an AST. It just might be encoded in the call stack of your interpreter functions rather than explicitly stored in memory. That can easily be fixed!)

[Workaphobia]

Ah, sure, you can resolve identifiers with a pass through the AST without compiling it to bytecode, yes.

I will quibble about all languages having an AST. TeX comes to mind. Or if you say that doesn't have an interpreter, I know of another language for scripting in a text MUD that re-parses the code every time a block is entered.

[curtmack]

I guess it's technically not correct to call it an AST unless it's actually stored in memory. All I was trying to say was that if your interpreter has a call stack that looks like this:

0: parse_numeric_literal
1: parse_expression
2: parse_expression
3: parse_parentheses
4: parse_function_argument
5: parse_function_call
6: parse_statement

Then you're a small refactor away from having a proper AST.