transduce: Isomorphic ParsingSee this example from lib.rs:
rust
let parser = exact('(') >> verbatim() << exact(')') << end();
let input = "(*)";
assert_eq!(
parser.parse(input.chars()),
Ok('*'),
);
// Or, equivalently:
assert_eq!(
parenthesized(verbatim()).parse(input.chars()),
Ok('*'),
);
This does exactly what it looks like it does.
Equivalently,
rust
assert_eq!(parenthesized(verbatim()).parse(rawstr.chars()), Ok('*'))
The parse method automatically locates the error (even for user-defined parsers) and prints out gorgeous, colored Rust-style errors:
rust
(exact(b'?') >> exact(b'?')).parse_or_panic(b"???");
...| Error while parsing:
1 | ???
| ^ Unparsed input remains after parsing what should have been everything
rust
(verbatim() & verbatim() & verbatim() & verbatim()).parse_or_panic(b"???");
...| Error while parsing:
1 | ???
| ^ Reached end of input but expected an item
rust
(verbatim() << exact(b'!')).parse_or_panic(b"???")
...| Error while parsing:
1 | ???
| ^ Expected 33 but found 63
Huge shoutout to UPenn's CIS 194 and Haskell's higher-order parsing libraries I learned in 194.
Removing boxed closures once this feature is stabilized.
Already works with the feature-gate enabled: just enable the nightly feature on this crate.
I haven't benchmarked yet, but when the name of a type fills almost the entire screen and encodes a needless abstraction with runtime cost, it's gotta go on moral principle.