ast

What a linter actually is, what its rules enforce, how AST-based analysis works, the cost of auto-fix, the ecosystem (ESLint, Ruff, Clippy, golangci-lint), where to wire it in (LSP / pre-commit / CI), why false-positive rate is the real budget, and when a custom rule pays for itself.

The parser takes a flat token stream and recovers the hierarchical structure the programmer intended. Learn context-free grammars, recursive-descent parsing, operator precedence, the difference between a parse tree and an AST, and when LL versus LR parsers matter — including the classic dangling-else ambiguity.