It's been around two and a half years, and many versions, since this
warning was first introduced, so it feels reasonable to finally turn it
into a hard error. It will remain a special-cased error for a little
while.
Modifies parsing to return strongly-typed `Thunk`s, which contain both
the function implementation, as well as the correct number of arguments.
This moves unknown function and function argument count mismatch errors
to parse time.
Make analysis resolve recipe dependencies from names (`Name`) to recipes
(`Rc<Recipe>`), to give type-level certainty that resolution was performed
correctly and remove the need to look up dependencies on run.
Borrow errors produced by an older version of rust forced us to create
copies of errors in the recipe resolver. The borrow checker appears to
have evolved to the point where these copies are unnecessary, so this
diff removes them.
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.
`env_var(key)` looks up the value of the environment variable with name `key`, aborting execution if it is not found.
`env_var_or_default(key, default)` looks up the value of the environment variable with name `key`, returning `default` if it is not found.
