Statements and ;

[vkz]

BSJS grammars seem to be quite frivolous with how they parse and particularly generate JS code.

var source = "function test() { for(var i = 0;i < 2;i++) { }; return [];}";

Of interest are ; before return and the one before the last }. Parsing and then generating JS using ometa BSJS grammars will produce:

function test(){for(var i = 0;i < 2;i++){};undefined;return []}

• undefined; is there because at the moment empty statements are parsed into ['stmt', ['get', 'undefined']]. We should probably have a separate type for those
• ; after the very last statement gets dropped completely. This is because curlyTrans rule in BSJSTranslator simply joins all statements with rs.join(';'). Another consequence of joining is pervasive ; even after statements that didn't have semicolons after them in the original source. Latter is mostly problematic if we want to preserve the code-style of the origin (more or less). Esprima + Escodegen do the right thing here.

[vkz]

Not submitting PRs cause the issue may appear subjective and therefore we should discuss before moving fwd with changes.