Strict Mode Lex/Parse

[Lan2u]

ECMASCript feature
As per https://tc39.es/ecma262/#sec-strict-mode-code and https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Strict_mode ECMAScript can be processed using either strict or unstrict mode. When parsing/lexing we currently only account for the strict case in a few select areas such as number lexing however in-order for boa to support strict mode fully we need to expand this to other areas.

Example code
For example, the following code is processed by boa fine when it should produce a SyntaxError as 'implements' is a reserved keyword in strict mode code.

    'use strict';
    var implements;

Initially, I'm planning to focus on the lexing/parsing side and then the interpreting side can come after.

• Strict mode number lexing/parsing
• Strict mode dis-allowed keywords
• Strict mode identifier lexing/parsing
• Strict mode directive-prologue parsing
• Strict mode function argument parsing

Will add more as I come across them