nandi.uk
Fork of daniellemaywood.uk/gleam — Wasm codegen work
Reexport Erlang types for externally annotated types
author
Gears
committer
Louis Pilfold
date
(Oct 27, 2025, 4:31 PM UTC)
commit
d19d5f82
d19d5f82b04273e5ed8793971a44fafb0c4ee3c6
parent
741b9135
741b9135528c51b243dc64bbfa8db33824c44da5
change-id
tnzkxwwv
tnzkxwwvnvzkqppwvyknzqztnnnqunmz
+87
-3
+21
-3
compiler-core/src/erlang.rs
+21
-3
compiler-core/src/erlang.rs
···
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constructors,
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typed_parameters,
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opaque,
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+
external_erlang,
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..
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}) => {
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// Erlang doesn't allow phantom type variables in type definitions but gleam does
···
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);
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// Type definitions
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let definition = if constructors.is_empty() {
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-
let constructors =
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-
std::iter::once("any()".to_doc()).chain(phantom_vars_constructor);
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join(constructors, break_(" |", " | "))
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if let Some((module, external_type, _location)) = external_erlang {
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let printer = TypePrinter::new(module_name);
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docvec![
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module,
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":",
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external_type,
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"(",
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join(
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typed_parameters
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.iter()
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.map(|parameter| printer.print(parameter)),
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", ".to_doc()
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),
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")"
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]
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} else {
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let constructors =
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std::iter::once("any()".to_doc()).chain(phantom_vars_constructor);
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join(constructors, break_(" |", " | "))
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}
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} else {
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let constructors = constructors
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.iter()
+23
compiler-core/src/erlang/tests/custom_types.rs
+23
compiler-core/src/erlang/tests/custom_types.rs
···
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fn phantom() {
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assert_erl!("pub type Map(k, v)");
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}
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+
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#[test]
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fn annotated_external_type() {
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assert_erl!(
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r#"
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@external(erlang, "gleam_stdlib", "dict")
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pub type Dict(key, value)
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"#
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);
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}
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+
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#[test]
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fn annotated_external_type_used_in_function() {
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assert_erl!(
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r#"
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@external(erlang, "gleam_stdlib", "dict")
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pub type Dict(key, value)
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+
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@external(erlang, "maps", "get")
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pub fn get(dict: Dict(key, value), key: key) -> Result(value, Nil)
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"#
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);
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}
+17
compiler-core/src/erlang/tests/snapshots/gleam_core__erlang__tests__custom_types__annotated_external_type.snap
+17
compiler-core/src/erlang/tests/snapshots/gleam_core__erlang__tests__custom_types__annotated_external_type.snap
···
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+
---
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source: compiler-core/src/erlang/tests/custom_types.rs
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expression: "\n@external(erlang, \"gleam_stdlib\", \"dict\")\npub type Dict(key, value)\n"
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---
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----- SOURCE CODE
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+
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@external(erlang, "gleam_stdlib", "dict")
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pub type Dict(key, value)
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+
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+
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----- COMPILED ERLANG
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-module(my@mod).
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-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
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-define(FILEPATH, "project/test/my/mod.gleam").
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-export_type([dict/2]).
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+
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-type dict(I, J) :: gleam_stdlib:dict(I, J).
+26
compiler-core/src/erlang/tests/snapshots/gleam_core__erlang__tests__custom_types__annotated_external_type_used_in_function.snap
+26
compiler-core/src/erlang/tests/snapshots/gleam_core__erlang__tests__custom_types__annotated_external_type_used_in_function.snap
···
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+
---
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source: compiler-core/src/erlang/tests/custom_types.rs
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expression: "\n@external(erlang, \"gleam_stdlib\", \"dict\")\npub type Dict(key, value)\n\n@external(erlang, \"maps\", \"get\")\npub fn get(dict: Dict(key, value), key: key) -> Result(value, Nil)\n"
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---
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----- SOURCE CODE
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@external(erlang, "gleam_stdlib", "dict")
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pub type Dict(key, value)
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@external(erlang, "maps", "get")
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pub fn get(dict: Dict(key, value), key: key) -> Result(value, Nil)
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+
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+
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----- COMPILED ERLANG
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-module(my@mod).
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-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
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-define(FILEPATH, "project/test/my/mod.gleam").
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-export([get/2]).
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-export_type([dict/2]).
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+
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-type dict(I, J) :: gleam_stdlib:dict(I, J).
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+
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-file("project/test/my/mod.gleam", 6).
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-spec get(dict(K, L), K) -> {ok, L} | {error, nil}.
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get(Dict, Key) ->
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maps:get(Dict, Key).