Ast_invariants(3)

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version 5.5.0 · 19 versions
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✨ Ast_invariants ✨

okay so bestie, this is a page from the OCaml library manual, and honestly? it's a little niche but it's giving compiler internals realness 💅 so let's get into it.

🦋 NAME 🦋

Ast_invariants — literally just: Check AST invariants. that's the whole vibe check, no cap.

🎀 Module 🎀

the module is called Ast_invariants, bestie. say it with me. 🌸

💖 Documentation 💖

so the module itself is Module Ast_invariants and its signature is : sig end — yeah, it's an anonymous-ish sig situation, that's just how OCamldoc prints it, don't come for me 🙈

and what does it do? Check AST invariants. icon behaviour, truly. 👑

⚠️ Warning: this module is unstable and it's part of Compiler_libs. so like, use it but know it might shift under you, ngl. unstable means unstable, fr fr.

🌈 the values 🌈

  • val structure : Parsetree.structure -> unit — takes a Parsetree.structure and gives you back unit. that's it. that's the whole function. slay. ✨
  • val signature : Parsetree.signature -> unit — same energy, but for a Parsetree.signature → unit. 🫶
  • val check_loc_ghost : (Ast_iterator.iterator -> Ast_iterator.iterator -> 'a -> unit) -> 'a -> source_contents:string -> unit — okay this one's the main character 👑. it checks the invariant of Location.t's loc_ghost field — the ones that are stated in location.mli. (yes, location.mli is the source of truth here, go read it, iykyk 💀)

you can run this with -dparsetree-loc-ghost-invariants, which is used slightly in the testsuite — but honestly it should be used more, so we can find more of the places where the invariant is broken. like, more coverage bestie, we're begging 🥺

lowkey a reminder that check_loc_ghost takes a function of two Ast_iterator.iterator args, then 'a, and a labelled source_contents:string — keep those exactly as written, they're load-bearing 💀

and that's the page!! 🌸🦋💜

sign-off szn: this lil doc was made with OCamldoc, dated 2026-06-22, and it's page Ast_invariants(3) of the OCaml library manual. mwah, go check those invariants 💋✨

📦 where this page comes from