From c1ef0ee50686f58414cdd1ae8c1b92ad2fd5419a Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Sat, 20 Nov 2021 02:33:09 -0800
Subject: [PATCH] More parser refactoring

---
 schala-lang/src/parsing/combinator.rs |  8 +++---
 schala-lang/src/parsing/mod.rs        | 39 ++++++++++++++++++---------
 schala-lang/src/parsing/test.rs       |  2 +-
 3 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/schala-lang/src/parsing/combinator.rs b/schala-lang/src/parsing/combinator.rs
index 740cdaf..e959d19 100644
--- a/schala-lang/src/parsing/combinator.rs
+++ b/schala-lang/src/parsing/combinator.rs
@@ -17,11 +17,13 @@ use nom::{
 };
 use nom_locate::{position, LocatedSpan};
 
-use crate::identifier::{Id, IdStore};
-use crate::parsing::StoreRef;
+use crate::{
+    identifier::{Id, IdStore},
+    parsing::StoreRef,
+};
 
 pub type Span<'a> = LocatedSpan<&'a str, StoreRef>;
-type ParseResult<'a, O> = IResult<Span<'a>, O, VerboseError<Span<'a>>>;
+pub type ParseResult<'a, O> = IResult<Span<'a>, O, VerboseError<Span<'a>>>;
 
 use crate::ast::*;
 
diff --git a/schala-lang/src/parsing/mod.rs b/schala-lang/src/parsing/mod.rs
index 93baa3f..80c016f 100644
--- a/schala-lang/src/parsing/mod.rs
+++ b/schala-lang/src/parsing/mod.rs
@@ -32,16 +32,7 @@ impl Parser {
 
     pub(crate) fn parse_comb(&mut self, input: &str) -> Result<AST, ParseError> {
         let span = Span::new_extra(input, self.id_store.clone());
-        let (rest, output) = combinator::program(span).map_err(|err| convert_err(input, err))?;
-
-        if rest.fragment() != &"" {
-            return Err(ParseError {
-                location: Default::default(),
-                msg: format!("Bad parse state, remaining text: `{}`", rest.fragment()),
-            });
-        }
-
-        Ok(output)
+        convert(input, combinator::program(span))
     }
 
     #[cfg(test)]
@@ -52,7 +43,7 @@ impl Parser {
     #[cfg(test)]
     fn expression_comb(&mut self, input: &str) -> Result<Expression, ParseError> {
         let span = Span::new_extra(input, self.id_store.clone());
-        combinator::expression(span).map_err(|err| convert_err(input, err)).map(|(rest, output)| output)
+        convert(input, combinator::expression(span))
     }
 
     #[cfg(test)]
@@ -63,7 +54,7 @@ impl Parser {
     #[cfg(test)]
     fn block_comb(&mut self, input: &str) -> Result<Block, ParseError> {
         let span = Span::new_extra(input, self.id_store.clone());
-        combinator::block(span).map_err(|err| convert_err(input, err)).map(|(_, output)| output)
+        convert(input, combinator::block(span))
     }
 
     fn fresh(&mut self) -> Id<ASTItem> {
@@ -71,6 +62,30 @@ impl Parser {
     }
 }
 
+fn convert<'a, O>(input: &'a str, result: combinator::ParseResult<'a, O>) -> Result<O, ParseError> {
+    use nom::{error::VerboseError, Err, Finish};
+
+    match result.finish() {
+        Ok((rest, output)) => {
+            if rest.fragment() != &"" {
+                return Err(ParseError {
+                    location: Default::default(),
+                    msg: format!("Bad parse state, remaining text: `{}`", rest.fragment()),
+                });
+            }
+
+            Ok(output)
+        }
+        Err(err) => {
+            let err = VerboseError {
+                errors: err.errors.into_iter().map(|(sp, kind)| (*sp.fragment(), kind)).collect(),
+            };
+            let msg = nom::error::convert_error(input, err);
+            Err(ParseError { msg, location: (0).into() })
+        }
+    }
+}
+
 fn convert_err<'a>(
     input: &'a str,
     err: nom::Err<nom::error::VerboseError<combinator::Span<'a>>>,
diff --git a/schala-lang/src/parsing/test.rs b/schala-lang/src/parsing/test.rs
index db5e890..0a4ae8d 100644
--- a/schala-lang/src/parsing/test.rs
+++ b/schala-lang/src/parsing/test.rs
@@ -192,7 +192,7 @@ fn basic_literals() {
     assert_expr!("0b0_1_0", expr(NatLiteral(2)));
     assert_expr!("0xff", expr(NatLiteral(255)));
     assert_expr!("0x032f", expr(NatLiteral(815)));
-    assert_expr!("0xf_f_", expr(NatLiteral(255)));
+    assert_expr!("0xf_f", expr(NatLiteral(255)));
     assert_expr!("false", expr(BoolLiteral(false)));
     assert_expr!("true", expr(BoolLiteral(true)));
 }