Symbol Import Aliases

Status

Future design. This is intentionally separated from current module artifact, stdlib modularization, and bytecode loading work. Current implemented conflict avoidance is module-qualified access:

import first.module as first;
import second.module as second;

first.name();
second.name();

Goal

Allow callers to keep short local names when two modules export symbols with the same public name, without weakening import provenance or trait/impl coherence.

Proposed Syntax

ImportDecl := ExportPrefix? "import" ModulePath ImportAlias? ImportList? ";"
ExportPrefix := "export"
ImportAlias := "as" Ident
ImportList := "(" ("*" | ImportItem ("," ImportItem)*) ")"
ImportItem := Ident ("as" Ident)?

Examples:

import first.module (name as firstName);
import second.module (name as secondName);

export import std.string (join as stringJoin);

Semantics

• import m (aaa as bbb); binds local name bbb to exported symbol aaa.
• Provenance records the canonical source module ID and original exported name separately from the local alias.
• Conflict checks are local-name based. aaa as bbb conflicts with any other imported or local symbol named bbb from a different source.
• Re-importing the same original symbol from the same canonical source under the same local alias is idempotent.
• Diagnostics must report the local alias, original symbol, and canonical source module.
• export import m (aaa as bbb); exports bbb as this module's public symbol, while preserving provenance to m::aaa.
• Module-qualified imports remain available and are preferred when many symbols from both modules are needed.
• use impl Trait for Type continues to use module qualifiers and canonical module IDs. Symbol aliases do not create new trait or type identities.

Required Data

• AST import item structure with exportedName and optional localName.
• Runtime/module artifact import provenance entries containing: local name, original exported name, canonical source module ID.
• Typechecker import metadata that distinguishes local alias from original export name for diagnostics and re-export artifact publication.
• ORGASM import metadata that can emit CALL_IMPORT by original exported name while binding the local alias during compilation.

Acceptance Criteria

• Parser accepts import m (aaa as bbb); and rejects malformed alias items.
• STUPID and ORGASM both execute calls through aliased imported functions.
• Imported values, functions, types, traits, and impl evidence preserve original module provenance through aliases.
• Conflicts are detected by local name and include both source modules in the diagnostic.
• export import m (aaa as bbb); re-exports bbb and downstream imports can use bbb without knowing the original aaa name.
• .ngo artifacts preserve alias metadata so source and bytecode modules expose the same public symbols.