Brummel
b9ca8894a5
Adds form-A surface (borrow T) / (own T) wrappers in fn-type
params and ret slots. Internally these are not new Type variants
but per-position metadata on Type::Fn:
Type::Fn { params, param_modes, ret, ret_mode, effects }
enum ParamMode { Implicit, Own, Borrow }
This keeps Type itself unchanged, so unification, occurs, apply,
and ~190 other Type match-arms in the typechecker need no new
branch. Fields use serde skip-if-default predicates so canonical
JSON hashes for every pre-18a fixture stay bit-identical (sum,
list, hof, closure, list_map, etc.: zero diff under git).
Iter 18a is purely additive: typechecker treats modes as
transparent (mode-compat check deferred to 18c), no codegen
change (--alloc=gc / Boehm path unchanged), no linearity
enforcement. The annotation info flows into the JSON side-table
that 18c will consume.
Equality of mode slices is length-tolerant: a vec![] (the form
written by mechanically-updated construction sites that elide
modes) compares equal to vec![Implicit; n]. This kept the patch
from being a 100-site mechanical migration through the
typechecker. 18c will choose: keep the slack, or normalise to
full-length on construction.
New fixture examples/borrow_own_demo.{ailx,ail.json} exercises
both modes. list_length declares (borrow (con List)); sum_list
declares (own (con List)). Stdout: 3 then 6.
Documentation: DESIGN.md schema-additions block clarified that
modes are Type::Fn metadata (not Type variants); migration plan
flag rename --memory=rc → --alloc=rc to match the existing CLI
flag.
Verification:
- cargo build --workspace green
- cargo test --workspace green (154 tests, +1 vs baseline 153)
- git diff examples/{sum,list,hof,closure,list_map,...}.ail.json: empty
- borrow_own_demo runtime stdout: "3\n6\n"
- canonical JSON contains "param_modes":["borrow"] and ["own"]
1 line
2.4 KiB
JSON
1 line
2.4 KiB
JSON
{"defs":[{"ctors":[{"fields":[],"name":"Nil"},{"fields":[{"k":"con","name":"Int"},{"k":"con","name":"List"}],"name":"Cons"}],"doc":"Monomorphic singly-linked Int list — boxed, recursive.","kind":"type","name":"List"},{"body":{"arms":[{"body":{"lit":{"kind":"int","value":0},"t":"lit"},"pat":{"ctor":"Nil","fields":[],"p":"ctor"}},{"body":{"args":[{"lit":{"kind":"int","value":1},"t":"lit"},{"args":[{"name":"t","t":"var"}],"fn":{"name":"list_length","t":"var"},"t":"app"}],"fn":{"name":"+","t":"var"},"t":"app"},"pat":{"ctor":"Cons","fields":[{"name":"h","p":"var"},{"name":"t","p":"var"}],"p":"ctor"}}],"scrutinee":{"name":"xs","t":"var"},"t":"match"},"doc":"Borrow xs, count its elements. Iter 18a: `(borrow (con List))`.","kind":"fn","name":"list_length","params":["xs"],"type":{"effects":[],"k":"fn","param_modes":["borrow"],"params":[{"k":"con","name":"List"}],"ret":{"k":"con","name":"Int"}}},{"body":{"arms":[{"body":{"lit":{"kind":"int","value":0},"t":"lit"},"pat":{"ctor":"Nil","fields":[],"p":"ctor"}},{"body":{"args":[{"name":"h","t":"var"},{"args":[{"name":"t","t":"var"}],"fn":{"name":"sum_list","t":"var"},"t":"app"}],"fn":{"name":"+","t":"var"},"t":"app"},"pat":{"ctor":"Cons","fields":[{"name":"h","p":"var"},{"name":"t","p":"var"}],"p":"ctor"}}],"scrutinee":{"name":"xs","t":"var"},"t":"match"},"doc":"Consume xs, sum its elements. Iter 18a: `(own (con List))`.","kind":"fn","name":"sum_list","params":["xs"],"type":{"effects":[],"k":"fn","param_modes":["own"],"params":[{"k":"con","name":"List"}],"ret":{"k":"con","name":"Int"}}},{"body":{"body":{"lhs":{"args":[{"args":[{"name":"xs","t":"var"}],"fn":{"name":"list_length","t":"var"},"t":"app"}],"op":"io/print_int","t":"do"},"rhs":{"args":[{"args":[{"name":"xs","t":"var"}],"fn":{"name":"sum_list","t":"var"},"t":"app"}],"op":"io/print_int","t":"do"},"t":"seq"},"name":"xs","t":"let","value":{"args":[{"lit":{"kind":"int","value":1},"t":"lit"},{"args":[{"lit":{"kind":"int","value":2},"t":"lit"},{"args":[{"lit":{"kind":"int","value":3},"t":"lit"},{"args":[],"ctor":"Nil","t":"ctor","type":"List"}],"ctor":"Cons","t":"ctor","type":"List"}],"ctor":"Cons","t":"ctor","type":"List"}],"ctor":"Cons","t":"ctor","type":"List"}},"doc":"Build [1,2,3]; print list_length (3) then sum_list (6).","kind":"fn","name":"main","params":[],"type":{"effects":["IO"],"k":"fn","params":[],"ret":{"k":"con","name":"Unit"}}}],"imports":[],"name":"borrow_own_demo","schema":"ailang/v0"} |