feat(motoko): emit type alias names as PascalCase#729
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feat(motoko): emit type alias names as PascalCase#729
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Candid type aliases are now rendered in UpperCamelCase in generated Motoko bindings (e.g. `my_type` → `MyType`). When two names would map to the same UpperCamelCase form (e.g. `A` and `a`), the collision is detected and the original escaped name is kept instead. `Self` is always reserved as it is emitted verbatim by the actor declaration. All-separator inputs (e.g. `_`) that produce an empty transform also fall back to the original name. Adds `to_upper_camel_case`, `escape_str` (string-returning escape helper reused by both `escape` and the collision fallback), and `type_display_name` which performs the collision check against the full `TypeEnv`. All printer functions now accept `env: &TypeEnv`, mirroring the TypeScript binding generator. Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Cursor <cursoragent@cursor.com>
Kamirus
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Co-authored-by: Cursor <cursoragent@cursor.com>
- Introduce BindingCtx<'a> (Copy+Clone) bundling env + precomputed names map, threaded through all printer functions instead of bare &TypeEnv. compile_inner handles the lifetime split. - build_names() runs one O(N) pass over env to count PascalCase collisions, then assigns display names in a second pass — replaces the previous O(N²) per-type env scan. - to_pascal_case() simplified: just requires lowercase first char, no artificial domain restrictions needed since build_names sees all names at once and detects collisions via count map. - Rename Ctx → BindingCtx; pp_defs uses ctx.names[id] (infallible). - Add pascal_collision.did and self_type.did test fixtures covering two-name PascalCase collisions, verbatim env-key collisions, and the Self reservation guard. - CHANGELOG: document breaking PascalCase rename. Co-authored-by: Cursor <cursoragent@cursor.com>
- build_names: pass 1 assigns collision-free escape_str fallbacks, pass 2 upgrades to PascalCase where unclaimed — no implicit ordering dependency, fallback collisions provably impossible. - to_pascal_case simplified: just requires lowercase first char. - Rename Ctx → BindingCtx; pp_defs uses ctx.names[id] (infallible). - Remove dead env.0.contains_key collision proxy. - Trim comments throughout. Co-authored-by: Cursor <cursoragent@cursor.com>
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This is motivated by caffeinelabs/mops-ic#7, where I plan to set up automatic regeneration of the management canister Motoko package — idiomatic naming is essential when the output is consumed directly without manual editing.
What
Generated Motoko bindings now render type alias names in PascalCase (e.g.
my_type→MyType,list→List).Why
Motoko types are conventionally PascalCase — the stdlib, the language spec, and the compiler's own style all follow this. Generated bindings that emit
type my_type = ...are immediately out of place: developers either tolerate the inconsistency or write manual re-alias wrappers every time. This change makes generated code idiomatic and directly usable without wrapping.Migration
Rename any references to generated type aliases from their old snake_case form to PascalCase:
Edge cases handled
Aandaboth →A), the collider keeps its original escaped name. The first name alphabetically wins the PascalCase slot.Selfreservation: always reserved —pp_actoremits it verbatim for the actor declaration._) fall back to the escaped original.These guarantees ensure generated bindings always compile.