3 releases (breaking)
0.3.0 | Mar 21, 2024 |
---|---|
0.2.0 | Feb 17, 2024 |
0.1.0 | Feb 16, 2024 |
#361 in Procedural macros
Used in 3 crates
145KB
3K
SLoC
proclet: proc macros made easy
⚠️
proclet
is still in early development. It's missing some basic features and may get major design changes, and documentation is a work in progress.
proclet
can be used with either proc-macro or proc-macro2, or both. Most of the types
of the proc-macro crates are abstracted into traits, and proclet
's types are generic
over these traits. If you run into type inference issues, there's proc-macro specific
aliases for the proclet types in the pm1
and pm2
modules.
Here's how you'd make a proc macro that takes a set of comma separated strings as arguments (last comma optional):
#[proc_macro]
pub fn my_proc_macro(input: TokenStream) -> TokenStream {
proclet(input, |input| {
let args = punctuated(StringLiteral::parser(), op(",")).parse_all(input)?;
// ...
})
}
The proclet
function is an optional wrapper that converts the input to a TokenBuf
ready
for parsing, converts the output back into a TokenStream
, and handles errors by making them
nice spanned compiler errors instead of panics.
parse_all
returns an error if there's tokens left in the buffer after parsing. To leave
the rest of the buffer for the next parser to parse, use the parse
method instead.
You can combine parsers to parse more complex objects like punctuated
does in the example
above. Types that implement the Parse
trait can be parsed directly:
let string = StringLiteral::parse(input)?;
The input
is automatically advanced to point past the parsed object on success.