diff options
author | Profpatsch <mail@profpatsch.de> | 2020-06-02 00:41:29 +0200 |
---|---|---|
committer | Profpatsch <mail@profpatsch.de> | 2020-06-02 00:41:29 +0200 |
commit | 723192c4c89a08eff3d4bcb43fbbb1ba4458027b (patch) | |
tree | b35d930545dd3d81cb3c69d1d8b9761042ba0105 /pkgs/profpatsch/encode | |
parent | b1717c994907eb6ff1b1021c1706573781f846c2 (diff) |
pkgs/profpatsch/encode: initial rust parser
Uses the nom parsing combinator library.
Diffstat (limited to 'pkgs/profpatsch/encode')
-rw-r--r-- | pkgs/profpatsch/encode/default.nix | 39 | ||||
-rw-r--r-- | pkgs/profpatsch/encode/encode.rs | 342 |
2 files changed, 381 insertions, 0 deletions
diff --git a/pkgs/profpatsch/encode/default.nix b/pkgs/profpatsch/encode/default.nix new file mode 100644 index 00000000..2101ebbd --- /dev/null +++ b/pkgs/profpatsch/encode/default.nix @@ -0,0 +1,39 @@ +{ pkgs, writeRustSimpleBin }: + +let + version-check = pkgs.buildRustCrate { + pname = "version-check"; + version = "0.9.2"; + crateName = "version-check"; + sha256 = "1vwvc1mzwv8ana9jv8z933p2xzgj1533qwwl5zr8mi89azyhq21v"; + }; + memchr = pkgs.buildRustCrate { + pname = "memchr"; + version = "2.3.3"; + crateName = "memchr"; + sha256 = "1ivxvlswglk6wd46gadkbbsknr94gwryk6y21v64ja7x4icrpihw"; + }; + nom = pkgs.buildRustCrate { + pname = "nom"; + version = "5.1.1"; + crateName = "nom"; + sha256 = "1gb4r6mjwd645jqh02nhn60i7qkw8cgy3xq1r4clnmvz3cmkv1l0"; + dependencies = [ memchr ]; + buildDependencies = [ version-check ]; + features = [ "std" "alloc" ]; + }; + + encode-rs-common = tests: writeRustSimpleBin "encode" { + dependencies = [ nom ]; + buildTests = tests; + release = false; + verbose = true; + } ./encode.rs ; + + encode-rs-tests = encode-rs-common true; + +in { + inherit + encode-rs-tests + ; +} diff --git a/pkgs/profpatsch/encode/encode.rs b/pkgs/profpatsch/encode/encode.rs new file mode 100644 index 00000000..9b3f73c9 --- /dev/null +++ b/pkgs/profpatsch/encode/encode.rs @@ -0,0 +1,342 @@ +extern crate nom; + +use nom::{ + IResult +}; + +use std::str::FromStr; +use std::ops::Neg; +use std::collections::HashMap; +use nom::bytes::complete::{tag, take}; +use nom::branch::{alt}; +use nom::character::complete::{digit1, char}; +use nom::sequence::{tuple}; +use nom::combinator::{map, map_res, flat_map, opt}; +use nom::error::{context, ErrorKind, ParseError}; + +#[derive(Debug, PartialEq, Eq, Clone)] +struct Tag { + tag: String, + val: Box<T> +} + +#[derive(Debug, PartialEq, Eq, Clone)] +enum T { + // Unit + Unit, + // Naturals + N3(u8), + N6(u64), + N7(u128), + // Integers + I3(i8), + I6(i64), + I7(i128), + // Text + Text(String), + // Tags + Sum(Tag), + Record(HashMap<String, Box<T>>), + List(Box<Vec<T>>), +} + +#[derive(Debug, PartialEq, Eq)] +enum Err { + Empty, + ParseLen, +} + +fn unit_t(s: &[u8]) -> IResult<&[u8], ()> { + let (s, _) = context("unit", tag("u,"))(s)?; + Ok((s, ())) +} + +fn usize_t(s: &[u8]) -> IResult<&[u8], usize> { + context( + "usize", + map_res( + map_res(digit1, |n| std::str::from_utf8(n)), + |s| s.parse::<usize>()) + )(s) +} + + +fn uint_t<'a, I: FromStr + 'a>(t: &'static str) -> impl Fn(&'a [u8]) -> IResult<&'a [u8], I> { + move |s: &'a [u8]| { + let (s, (_, _, int, _)) = tuple(( + tag(t.as_bytes()), + char(':'), + map_res( + map_res(digit1, |n: &[u8]| std::str::from_utf8(n)), + |s| s.parse::<I>() + ), + char(',') + ))(s)?; + Ok((s, int)) + } +} + +fn int_t<'a, I: FromStr + Neg<Output=I>>(t: &'static str) -> impl Fn(&'a [u8]) -> IResult<&[u8], I> { + context( + t, + move |s: &'a [u8]| { + let (s, (_, _, neg, int, _)) = tuple(( + tag(t.as_bytes()), + char(':'), + opt(char('-')), + map_res( + map_res(digit1, |n: &[u8]| std::str::from_utf8(n)), + |s| s.parse::<I>() + ), + char(',') + ))(s)?; + let res = match neg { + Some(_) => -int, + None => int, + }; + Ok((s, res)) + } + ) +} + +fn tag_t(s: &[u8]) -> IResult<&[u8], Tag> { + let (s, (_, len, _)) = tuple(( + char('<'), + usize_t, + char(':'), + ))(s)?; + let (s, (tag, _, recurse)) = tuple(( + take(len), + char('|'), + // recurses into the main parser + t_t + ))(s)?; + Ok((s, Tag { + tag: std::str::from_utf8(tag) + .map_err(|_| nom::Err::Failure((s, ErrorKind::Char))) + .map(|s| s.to_string())?, + val: Box::new(recurse) + })) +} + +/// parse text scalar (`t5:hello,`) +fn text(s: &[u8]) -> IResult<&[u8], T> { + let (s, (_, len, _)) = tuple(( + char('t'), + usize_t, + char(':') + ))(s)?; + let (s, (res, _)) = tuple(( + take(len), + char(',') + ))(s)?; + Ok((s, T::Text( + std::str::from_utf8(res) + .map_err(|_| nom::Err::Failure((s, ErrorKind::Char))) + .map(|s| s.to_string())?, + ))) +} + +fn list_t(s: &[u8]) -> IResult<&[u8], Vec<T>> { + let (s, (_, vec, _)) = tuple(( + char('['), + nom::multi::many0(t_t), + char(']') + ))(s)?; + Ok((s, vec)) +} + +fn record_t(s: &[u8]) -> IResult<&[u8], HashMap<String, Box<T>>> { + let (s, (_, map, _)) = tuple(( + char('{'), + nom::multi::fold_many1( + tag_t, + HashMap::new(), + |mut acc: HashMap<_, _>, Tag { tag, val }| { + // ignore duplicated tag names that appear later + if !acc.contains_key(&tag) { + acc.insert(tag, val); + } + acc + } + ), + char('}') + ))(s)?; + Ok((s, map)) +} + +fn t_t(s: &[u8]) -> IResult<&[u8], T> { + alt(( + text, + map(unit_t, |_| T::Unit), + map(tag_t, |t| T::Sum(t)), + map(list_t, |l| T::List(Box::new(l))), + map(record_t, |p| T::Record(p)), + + // 8, 64 and 128 bit + map(uint_t("n3"), |u| T::N3(u)), + map(uint_t("n6"), |u| T::N6(u)), + map(uint_t("n7"), |u| T::N7(u)), + map(int_t("i3"), |u| T::I3(u)), + map(int_t("i6"), |u| T::I6(u)), + map(int_t("i7"), |u| T::I7(u)), + + // less common + map(uint_t("n1"), |u| T::N3(u)), + map(uint_t("n2"), |u| T::N3(u)), + map(uint_t("n4"), |u| T::N6(u)), + map(uint_t("n5"), |u| T::N6(u)), + map(int_t("i1"), |u| T::I3(u)), + map(int_t("i2"), |u| T::I3(u)), + map(int_t("i4"), |u| T::I6(u)), + map(int_t("i5"), |u| T::I6(u)), + // TODO: 8, 9 not supported + ))(s) +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn test_parse_unit_t() { + assert_eq!( + unit_t("u,".as_bytes()), + Ok(("".as_bytes(), ())) + ); + } + + #[test] + fn test_parse_usize_t() { + assert_eq!( + usize_t("32foo".as_bytes()), + Ok(("foo".as_bytes(), 32)) + ); + } + + #[test] + fn test_parse_int_t() { + assert_eq!( + uint_t::<u8>("n3")("n3:42,abc".as_bytes()), + Ok(("abc".as_bytes(), 42)) + ); + assert_eq!( + uint_t::<u8>("n3")("n3:1024,abc".as_bytes()), + Err(nom::Err::Error(("1024,abc".as_bytes(), nom::error::ErrorKind::MapRes))) + ); + assert_eq!( + int_t::<i64>("i6")("i6:-23,abc".as_bytes()), + Ok(("abc".as_bytes(), -23)) + ); + assert_eq!( + int_t::<i128>("i3")("i3:0,:abc".as_bytes()), + Ok((":abc".as_bytes(), 0)) + ); + assert_eq!( + uint_t::<u8>("n7")("n7:09,".as_bytes()), + Ok(("".as_bytes(), 9)) + ); + // assert_eq!( + // length("c"), + // Err(nom::Err::Error(("c", nom::error::ErrorKind::Digit))) + // ); + // assert_eq!( + // length(":"), + // Err(nom::Err::Error((":", nom::error::ErrorKind::Digit))) + // ); + } + + #[test] + fn test_parse_text() { + assert_eq!( + text("t5:hello,".as_bytes()), + Ok(("".as_bytes(), T::Text("hello".to_owned()))) + ); + assert_eq!( + text("t4:fo,".as_bytes()), + // TODO: way better parse error messages + Err(nom::Err::Error(("fo,".as_bytes(), nom::error::ErrorKind::Eof))) + ); + assert_eq!( + text("t9:今日は,".as_bytes()), + Ok(("".as_bytes(), T::Text("今日は".to_owned()))) + ); + } + + #[test] + fn test_list() { + assert_eq!( + list_t("[]".as_bytes()), + Ok(("".as_bytes(), vec![])) + ); + assert_eq!( + list_t("[u,u,u,]".as_bytes()), + Ok(("".as_bytes(), vec![ + T::Unit, + T::Unit, + T::Unit, + ])) + ); + assert_eq!( + list_t("[u,[t3:foo,]u,]".as_bytes()), + Ok(("".as_bytes(), vec![ + T::Unit, + T::List(Box::new(vec![T::Text("foo".to_owned())])), + T::Unit, + ])) + ); + } + + #[test] + fn test_record() { + assert_eq!( + record_t("{<1:a|u,<1:b|u,<1:c|u,}".as_bytes()), + Ok(("".as_bytes(), vec![ + ("a".to_owned(), Box::new(T::Unit)), + ("b".to_owned(), Box::new(T::Unit)), + ("c".to_owned(), Box::new(T::Unit)), + ].into_iter().collect::<HashMap<String, Box<T>>>())) + ); + // duplicated keys are ignored (first is taken) + assert_eq!( + record_t("{<1:a|u,<1:b|u,<1:a|i1:-1,}".as_bytes()), + Ok(("".as_bytes(), vec![ + ("a".to_owned(), Box::new(T::Unit)), + ("b".to_owned(), Box::new(T::Unit)), + ].into_iter().collect::<HashMap<_,_>>())) + ); + } + + #[test] + fn test_parse() { + assert_eq!( + t_t("n3:255,".as_bytes()), + Ok(("".as_bytes(), T::N3(255))) + ); + assert_eq!( + t_t("t6:halloo,".as_bytes()), + Ok(("".as_bytes(), T::Text("halloo".to_owned()))) + ); + assert_eq!( + t_t("<3:foo|t6:halloo,".as_bytes()), + Ok(("".as_bytes(), T::Sum (Tag { + tag: "foo".to_owned(), + val: Box::new(T::Text("halloo".to_owned())) + }))) + ); + // { a: Unit + // , foo: List <A: Unit | B: List i3> } + assert_eq!( + t_t("{<1:a|u,<3:foo|[<1:A|u,<1:A|u,<1:B|[i3:127,]]}".as_bytes()), + Ok(("".as_bytes(), T::Record(vec![ + ("a".to_owned(), Box::new(T::Unit)), + ("foo".to_owned(), Box::new(T::List(Box::new(vec![ + T::Sum(Tag { tag: "A".to_owned(), val: Box::new(T::Unit) }), + T::Sum(Tag { tag: "A".to_owned(), val: Box::new(T::Unit) }), + T::Sum(Tag { tag: "B".to_owned(), val: Box::new(T::List(Box::new(vec![T::I3(127)]))) }), + ])))) + ].into_iter().collect::<HashMap<String, Box<T>>>()))) + ); + } + +} |