Currently, the AST produced by the parser is a dictionary of string ids. Consider: foo=Foo bar=Bar bar.attr=Attr This currently becomes: { foo: 'Foo', bar: { _: 'Bar', attr: 'Attr' }} I propose we change it to: [{id: 'foo', _: 'Foo'}, {id: 'bar', _: 'Bar', attr:'Attr'}] This will allow the AST to correctly represent cases where a duplicate id is found, which can then be handled by Locale or Context instances. In order to reduce the memory footprint, the Locale's AST which is serialized to JSON on buildtime should probably remain unchanged.

Let's land the first part of bug 1022859 before working on this.

Zibi fixed this in bug 1081040: https://github.com/l20n/l20n.js/commit/8b45ed11c81185084e0ace3cb80c68b110bc7d2d