- Combine and simplify string and backtick lexing.
- Allow newlines in strings and backticks.
- Add triple-delimited indented strings and backticks. Common indented literal non-blank line leading whitespace is stripped.
- If a literal newline is escaped, it will be suppressed.
- Backticks starting with `#!` are reserved for a future upgrade.
Just's first parser performed both parsing, i.e the transformation of a
token stream according to the language grammar, and a number of consistency
checks and analysis passes.
This made parsing and analysis quite complex, so this diff introduces a
new, much cleaner `Parser`, and moves existing analysis into a dedicated
`Analyzer`.
Eventually, there will probably be a `crate` visibility specifier that
does the same thing as `pub(crate)`. This commit replaces `pub` with
`pub(crate)`, so when `crate` is available we can easily switch to it.
