divide atom parser into sub-parsers with context

Cargo.toml

@@ -21,6 +21,7 @@ bng_macros = { path = "bng_macros" }
 const_format = "0.2.33"
 thiserror = "1.0.64"
 derive-new = "0.7.0"
+naan = "0.1.32"
 
 [features]
 default = ["play", "save"]

src/bng/score.rs

@@ -8,7 +8,6 @@ use anyhow::Context;
 use bng_macros::{ModifierParser, QuickModifierParser, SlopeModifierParser};
 use derive_new::new;
 use derived_deref::Deref;
-use lex::lexer::atom;
 use nom::{
     branch::alt,
     character::{complete::char, streaming::one_of},

src/bng/score/de.rs

@@ -1,9 +1,11 @@
 use std::{
     fmt::{Debug, Display},
     num::TryFromIntError,
+    ops::Deref,
 };
 
 use derive_new::new;
+use naan::fun::{F1Once, F2Once};
 use nom::{
     character::complete::one_of,
     combinator::all_consuming,
@@ -18,7 +20,7 @@ use serde::{
 };
 use thiserror::Error;
 
-use crate::bng::score::lex::lexer::atom;
+use crate::bng::score::lex::lexer::root;
 
 use super::{
     utils::{inflate, InflateError},
@@ -54,11 +56,7 @@ impl<'de> Deserialize<'de> for Atoms {
             Ok(Default::default())
         } else {
             root(&sheet, &notes)
-                .map_err(|e: nom::Err<VerboseError<&str>>| match e {
-                    nom::Err::Incomplete(Needed::Unknown) => "needed some more bytes".to_string(),
-                    nom::Err::Incomplete(Needed::Size(n)) => format!("needed {} more bytes", n),
-                    nom::Err::Error(e) | nom::Err::Failure(e) => convert_error(sheet.as_str(), e),
-                })
+                .map_err(|e| pretty_verbose_err.curry().call1(sheet.as_str()).call1(e))
                 .map_err(AtomsSerializeError::Parsing)
                 .map_err(de::Error::custom)
                 .and_then(|(_, v)| {
@@ -71,22 +69,13 @@ impl<'de> Deserialize<'de> for Atoms {
     }
 }
 
-fn maybe_yml_str_space<'a, E>() -> impl Parser<&'a str, Vec<char>, E>
+fn pretty_verbose_err<I>(input: I, e: nom::Err<VerboseError<I>>) -> String
 where
-    E: nom::error::ParseError<&'a str> + ContextError<&'a str>,
+    I: Deref<Target = str>,
 {
-    context("yml white space", many0(one_of(" \t\r\n")))
+    match e {
+        nom::Err::Incomplete(Needed::Unknown) => "needed some more bytes".to_string(),
+        nom::Err::Incomplete(Needed::Size(n)) => format!("needed {} more bytes", n),
+        nom::Err::Error(e) | nom::Err::Failure(e) => convert_error(input, e),
     }
-
-fn root<'a, E>(i: &'a str, notes: &'a str) -> IResult<&'a str, Vec<FlatAtom>, E>
-where
-    E: ParseError<&'a str>
-        + ContextError<&'a str>
-        + FromExternalError<&'a str, TryFromIntError>
-        + FromExternalError<&'a str, E>,
-{
-    all_consuming(terminated(
-        many1(preceded(maybe_yml_str_space(), atom(notes))),
-        maybe_yml_str_space(),
-    ))(i)
 }

src/bng/score/lex/lexer.rs

@@ -9,15 +9,13 @@ use nom::{
     branch::alt,
     bytes::complete::{take_till, take_till1},
     character::complete::{anychar, char, one_of, space1, u16, u8},
-    combinator::{map_opt, map_res, opt, value, verify},
+    combinator::{all_consuming, map_opt, map_res, opt, value, verify},
     error::{context, ContextError, ErrorKind, FromExternalError, ParseError},
-    multi::many0,
+    multi::{many0, many1},
     sequence::{delimited, pair, preceded, separated_pair, terminated},
     Err, IResult, Parser,
 };
 
-use crate::bng::score::{modifier, quick_modifier, slope_modifier};
-
 use super::{
     super::super::Expression as Instruction, Atom, FlatAtom, Modifier, QuickModifier, SlopeModifier,
 };
@@ -25,21 +23,81 @@ use super::{
 #[cfg(test)]
 mod tests;
 
-pub fn atom<'a, E>(notes: &'a str) -> impl Parser<&'a str, FlatAtom, E>
+fn maybe_yml_str_space<'a, E>() -> impl Parser<&'a str, Vec<char>, E>
+where
+    E: nom::error::ParseError<&'a str> + ContextError<&'a str>,
+{
+    context("yml white space", many0(one_of(" \t\r\n")))
+}
+
+pub fn root<'a, E>(i: &'a str, notes: &'a str) -> IResult<&'a str, Vec<FlatAtom>, E>
 where
     E: ParseError<&'a str>
         + ContextError<&'a str>
         + FromExternalError<&'a str, TryFromIntError>
         + FromExternalError<&'a str, E>,
+{
+    all_consuming(terminated(
+        many1(preceded(maybe_yml_str_space(), atom(notes))),
+        maybe_yml_str_space(),
+    ))(i)
+}
+
+fn note<'a, E>(notes: &'a str) -> impl Parser<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str> + FromExternalError<&'a str, TryFromIntError>,
 {
     context(
-        "atom",
-        alt((
+        "note",
         map_res(map_opt(one_of(notes), |c| notes.find(c)), u8::try_from).map(FlatAtom::Note),
-            value(FlatAtom::Rest, char(Atom::REST)),
+    )
+}
+
+fn rest<'a, E>(i: &'a str) -> IResult<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str>,
+{
+    context("rest", value(FlatAtom::Rest, char(Atom::REST)))(i)
+}
+
+fn start_here<'a, E>(i: &'a str) -> IResult<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str>,
+{
+    context(
+        "start_here",
         value(FlatAtom::StartHere, char(Atom::START_HERE)),
+    )(i)
+}
+
+fn modifier<'a, E>(i: &'a str) -> IResult<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str>,
+{
+    use super::super::modifier;
+    context(
+        "modifier",
         preceded(char(Atom::MODIFIER), modifier).map(FlatAtom::Modifier),
+    )(i)
+}
+
+fn quick_modifier<'a, E>(i: &'a str) -> IResult<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str>,
+{
+    use super::super::quick_modifier;
+    context(
+        "quick_modifier",
         quick_modifier.map(FlatAtom::QuickModifier),
+    )(i)
+}
+
+fn loop_starts<'a, E>(i: &'a str) -> IResult<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str>,
+{
+    context(
+        "loop_starts",
         preceded(
             char(Atom::LOOP.0),
             map_opt(opt(u8), |n| {
@@ -51,9 +109,43 @@ where
             }),
         )
         .map(FlatAtom::LoopStarts),
-            value(FlatAtom::LoopEnds, char(Atom::LOOP.1)),
+    )(i)
+}
+
+fn loop_ends<'a, E>(i: &'a str) -> IResult<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str>,
+{
+    context("loop_ends", value(FlatAtom::LoopEnds, char(Atom::LOOP.1)))(i)
+}
+
+fn tuple_starts<'a, E>(i: &'a str) -> IResult<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str>,
+{
+    context(
+        "tuple_starts",
         value(FlatAtom::TupleStarts, char(Atom::TUPLE.0)),
+    )(i)
+}
+
+fn tuple_ends<'a, E>(i: &'a str) -> IResult<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str>,
+{
+    context(
+        "tuple_ends",
         value(FlatAtom::TupleEnds, char(Atom::TUPLE.1)),
+    )(i)
+}
+
+fn slope_starts<'a, E>(i: &'a str) -> IResult<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str> + FromExternalError<&'a str, E>,
+{
+    use super::super::slope_modifier;
+    context(
+        "slope_starts",
         terminated(
             preceded(
                 char(Atom::SLOPE.0),
@@ -69,7 +161,25 @@ where
             char(','),
         )
         .map(|(sm, i)| FlatAtom::SlopeStarts(sm, i)),
+    )(i)
+}
+
+fn slope_ends<'a, E>(i: &'a str) -> IResult<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str>,
+{
+    context(
+        "slope_ends",
         value(FlatAtom::SlopeEnds, char(Atom::SLOPE.1)),
+    )(i)
+}
+
+fn comment<'a, E>(i: &'a str) -> IResult<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str> + ContextError<&'a str>,
+{
+    context(
+        "comment",
         value(
             FlatAtom::Comment,
             delimited(
@@ -78,6 +188,31 @@ where
                 char(Atom::COMMENT.1),
             ),
         ),
+    )(i)
+}
+
+fn atom<'a, E>(notes: &'a str) -> impl Parser<&'a str, FlatAtom, E>
+where
+    E: ParseError<&'a str>
+        + ContextError<&'a str>
+        + FromExternalError<&'a str, TryFromIntError>
+        + FromExternalError<&'a str, E>,
+{
+    context(
+        "atom",
+        alt((
+            note(notes),
+            rest,
+            start_here,
+            modifier,
+            quick_modifier,
+            loop_starts,
+            loop_ends,
+            tuple_starts,
+            tuple_ends,
+            slope_starts,
+            slope_ends,
+            comment,
         )),
     )
 }