root parser

src/bng/score/de.rs

@@ -1,13 +1,16 @@
-use std::fmt::{Debug, Display};
+use std::{
+    fmt::{Debug, Display},
+    num::TryFromIntError,
+};
 
 use derive_new::new;
 use nom::{
     character::complete::one_of,
     combinator::all_consuming,
-    error::{context, convert_error, ContextError, ParseError, VerboseError},
+    error::{context, convert_error, ContextError, FromExternalError, ParseError, VerboseError},
     multi::{many0, many1},
     sequence::{preceded, terminated},
-    Needed, Parser,
+    IResult, Needed, Parser,
 };
 use serde::{
     de::{self, Deserializer, Visitor},
@@ -50,23 +53,20 @@ impl<'de> Deserialize<'de> for Atoms {
         if sheet.is_empty() {
             Ok(Default::default())
         } else {
-            all_consuming(terminated(
-                many1(preceded(maybe_yml_str_space(), atom(&notes))),
-                maybe_yml_str_space(),
-            ))(&sheet)
-            .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(AtomsSerializeError::Parsing)
-            .map_err(de::Error::custom)
-            .and_then(|(_, v)| {
-                inflate(v)
-                    .map_err(AtomsSerializeError::from)
-                    .map_err(de::Error::custom)
-            })
-            .map(Atoms)
+            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(AtomsSerializeError::Parsing)
+                .map_err(de::Error::custom)
+                .and_then(|(_, v)| {
+                    inflate(v)
+                        .map_err(AtomsSerializeError::from)
+                        .map_err(de::Error::custom)
+                })
+                .map(Atoms)
         }
     }
 }
@@ -77,3 +77,16 @@ where
 {
     context("yml white space", many0(one_of(" \t\r\n")))
 }
+
+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)
+}