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I don't think creation of a syntax tree is always explicit; I have read C compiler source codes that use one pass with back-patching and the usable representati

I don't think creation of a syntax tree is always explicit; I have read C compiler source codes that use one pass with back-patching and the usable representation is bytecode or machine code. One could reckon that the AST is implicit during code generation as functions call each other to generate the code. A valid JS interpreter could just do what the statements say using dictionaries for each scope, linked together to allow levels of scope with the right semantics.

jcranmer 6y ago
It's worth noting that the scoping of names in C language is designed to be solvable in one pass: you can't use a function before it's declared. Most newer languages instead require a full pass to discover all the available names, to allow functions to not require a separate declaration before all uses.
deleted 6y ago
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