Program Lexer v6

Implement a lexer for the v6 language (modules + type annotations).

Function signature

func Lex(src string) ([]Token, error)

New token

• -> should be tokenized as ARROW.

The rest of the tokens are the same as v5:

• keywords: let, var, const, fn, if, else, while, for, return, break, continue, module, import, export, as, true, false, nil
• identifiers, numbers, strings
• operators and punctuation

Notes

• Type names (number, bool, string, array, map) are lexed as identifiers.
• Prefer readability over cleverness.