openharmony/third_party_rust_nom
1
0
Fork 0
mirror of https://gitee.com/openharmony/third_party_rust_nom synced 2024-11-23 07:29:54 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

add the length_value macro

Browse Source
This commit is contained in:
Geoffroy Couprie 2015-03-10 11:36:20 +01:00
parent 03f6ccf971
commit d01a00bca9
1 changed files with 125 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

125
src/macros.rs
View File

@ -669,6 +669,99 @@ macro_rules! take_until_either_and_leave(
)
);
/// returns a result without consuming the input
///
/// the embedded parser may return Incomplete
///
/// ```ignore
/// tag!(x "abcd");
/// peek!(ptag<&[u8], &[u8]> x);
/// let r = ptag(b"abcdefgh"));
/// assert_eq!(r, Done(b"abcdefgh", b"abcd"));
/// ```
#[macro_export]
macro_rules! length_value(
($name:ident<$i:ty,$o:ty> $f:ident $g:ident) => (
fn $name(input:$i) -> IResult<$i, Vec<$o>> {
match $f(input) {
Error(a) => Error(a),
Incomplete(i) => Incomplete(i),
Done(i1,nb) => {
let length_token = input.len() - i1.len();
let mut begin = 0;
let mut remaining = i1.len();
let mut res: Vec<$o> = Vec::new();
loop {
if res.len() == nb as usize {
return Done(&i1[begin..], res);
}
match $g(&i1[begin..]) {
Done(i2,o2) => {
res.push(o2);
let parsed = remaining - i2.len();
begin += parsed;
remaining = i2.len();
if begin >= i1.len() {
return Incomplete(Needed::Size((length_token + nb as usize * parsed) as u32));
}
},
Error(a) => return Error(a),
Incomplete(Needed::Unknown) => {
return Incomplete(Needed::Unknown)
},
Incomplete(Needed::Size(a)) => {
return Incomplete(Needed::Size(length_token as u32 + a * nb as u32))
}
}
}
}
}
}
);
($name:ident<$i:ty,$o:ty> $f:ident $g:ident $length:expr) => (
fn $name(input:$i) -> IResult<$i, Vec<$o>> {
match $f(input) {
Error(a) => Error(a),
Incomplete(i) => Incomplete(i),
Done(i1,nb) => {
let length_token = input.len() - i1.len();
let mut begin = 0;
let mut remaining = i1.len();
let mut res: Vec<$o> = Vec::new();
loop {
if res.len() == nb as usize {
return Done(&i1[begin..], res);
}
match $g(&i1[begin..]) {
Done(i2,o2) => {
res.push(o2);
let parsed = remaining - i2.len();
begin += parsed;
remaining = i2.len();
if begin >= i1.len() {
return Incomplete(Needed::Size((length_token + nb as usize * $length) as u32));
}
},
Error(a) => return Error(a),
Incomplete(Needed::Unknown) => {
return Incomplete(Needed::Unknown)
},
Incomplete(Needed::Size(a)) => {
return Incomplete(Needed::Size(length_token as u32 + $length * nb as u32))
}
}
}
}
}
}
);
);
#[cfg(test)]
mod tests {
use super::*;
@ -877,4 +970,36 @@ mod tests {
let r3 = x(b"abcefg");
assert_eq!(r3, Incomplete(Needed::Size(7)));
}
use nom::{be_u8,be_u16};
#[test]
fn length_value_test() {
length_value!(tst1<&[u8], u16 > be_u8 be_u16);
length_value!(tst2<&[u8], u16 > be_u8 be_u16 2);
let i1 = vec![0, 5, 6];
let i2 = vec![1, 5, 6, 3];
let i3 = vec![2, 5, 6, 3];
let i4 = vec![2, 5, 6, 3, 4, 5, 7];
let i5 = vec![3, 5, 6, 3, 4, 5];
let r1: Vec<u16> = Vec::new();
let r2: Vec<u16> = vec![1286];
let r4: Vec<u16> = vec![1286, 772];
assert_eq!(tst1(&i1), IResult::Done(&i1[1..], r1));
assert_eq!(tst1(&i2), IResult::Done(&i2[3..], r2));
assert_eq!(tst1(&i3), IResult::Incomplete(Needed::Size(5)));
assert_eq!(tst1(&i4), IResult::Done(&i4[5..], r4));
assert_eq!(tst1(&i5), IResult::Incomplete(Needed::Size(7)));
let r6: Vec<u16> = Vec::new();
let r7: Vec<u16> = vec![1286];
let r9: Vec<u16> = vec![1286, 772];
assert_eq!(tst2(&i1), IResult::Done(&i1[1..], r6));
assert_eq!(tst2(&i2), IResult::Done(&i2[3..], r7));
assert_eq!(tst2(&i3), IResult::Incomplete(Needed::Size(5)));
assert_eq!(tst2(&i4), IResult::Done(&i4[5..], r9));
assert_eq!(tst1(&i5), IResult::Incomplete(Needed::Size(7)));
}
}