0: https://github.com/microsoft/TypeScript/blob/db9e0079/src/compiler/program.ts#L1926# Parser

At a measly 8k lines long, the Parser is responsible for controlling a scanner (or two) and turning the output tokens from the scanner into an AST as the canonical representation of the source file.

Because the parser itself is effectively a state machine which creates nodes from scanning text there is some reasonable dancing

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