in lib/generator.js [1855:1875]
visitYield(ast, level) {
assert.equal(ast.type, 'yield');
this.emit('yield ', level);
if (!ast.expr) {
this.emit(';\n');
return;
}
if (ast.needCast) {
this.visitType(ast.expectedType);
this.emit('::fromMap(');
}
this.visitExpr(ast.expr, level);
if (ast.needCast) {
this.emit(')');
}
this.emit(';\n');
}