Unify lexing of backticks, cooked strings, and raw strings. Also allow
newlines in backticks and cooked strings, since I can't think of a reason
not to.
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.
Modify the lexer to keep track of opening `({[` and closing `]})` delimiters.
When the lexer would emit an eol or indent outside of a recipe when there
is at least one open delimiter, emit a whitespace token instead.
This allows expressions to be split on multiple lines, like so:
x := if 'a' == 'b' {
'x'
} else {
'y'
}
This does not work inside of recipe body interpolations, although this
restriction might relaxed in the future.
Add conditional expressions of the form:
foo := if lhs == rhs { then } else { otherwise }
`lhs`, `rhs`, `then`, and `otherwise` are all arbitrary expressions, and
can recursively include other conditionals. Conditionals short-circuit,
so the branch not taken isn't evaluated.
It is also possible to test for inequality with `==`.
Add a `set SETTING := VALUE` construct.
This construct is intended to be extended as needed with new settings,
but for now we're starting with `set shell := [COMMAND, ARG1, ...]`,
which allows setting the shell to use for recipe and backtick execution
in a justfile.
One of the primary reasons for adding this feature is to have a better
story on windows, where users are forced to scrounge up an `sh` binary
if they want to use `just`. This should allow them to use cmd.exe or
powershell in their justfiles, making just optionally dependency-free.
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.