From e60c60cbff71b84bdb50eff200675e696a251dbe Mon Sep 17 00:00:00 2001
From: Michael Sippel <micha@fragmental.art>
Date: Mon, 2 Oct 2023 15:05:25 +0200
Subject: [PATCH] parser: remove FromStr & always improve parse() function

---
 src/parser.rs      | 53 ++++++++++++++++------------------------------
 src/test/curry.rs  | 44 +++++++++++++++++++++-----------------
 src/test/parser.rs | 26 +++++++++++------------
 3 files changed, 55 insertions(+), 68 deletions(-)

diff --git a/src/parser.rs b/src/parser.rs
index e2c91f1..85ff9b4 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -20,24 +20,23 @@ pub enum ParseError {
 
 //<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>\\
 
-impl std::str::FromStr for TypeTerm {
-    type Err = ParseError;
-
-    fn from_str(s : &str) -> Result<Self, Self::Err> {
-        // creating a new context every time is not that useful..
-        let mut dict = TypeDict::new();
-        dict.parse(&mut LadderTypeLexer::from(s.chars()).peekable())
-    }
-}
-
-//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>\\
-
 impl TypeDict {
-    pub fn type_from_str(&mut self, s: &str) -> Result<TypeTerm, ParseError> {
-        self.parse(&mut LadderTypeLexer::from(s.chars()).peekable())
+    pub fn parse(&mut self, s: &str) -> Result<TypeTerm, ParseError> {
+        let mut tokens = LadderTypeLexer::from(s.chars()).peekable();
+
+        match self.parse_ladder(&mut tokens) {
+            Ok(t) => {
+                if let Some(_tok) = tokens.peek() {
+                    Err(ParseError::UnexpectedToken)
+                } else {
+                    Ok(t)
+                }
+            }
+            Err(err) => Err(err)
+        }
     }
 
-    fn parse_app<It>( &mut self, tokens: &mut Peekable<LadderTypeLexer<It>> ) -> Result<TypeTerm, ParseError>
+    fn parse_app<It>(&mut self, tokens: &mut Peekable<LadderTypeLexer<It>>) -> Result<TypeTerm, ParseError>
     where It: Iterator<Item = char>
     {
         let mut args = Vec::new();
@@ -48,7 +47,7 @@ impl TypeDict {
                     return Ok(TypeTerm::App(args));
                 }
                 _ => {
-                    match self.parse_partial(tokens) {
+                    match self.parse_ladder(tokens) {
                         Ok(a) => { args.push(a); }
                         Err(err) => { return Err(err); }
                     }
@@ -58,7 +57,7 @@ impl TypeDict {
         Err(ParseError::UnexpectedEnd)
     }
 
-    fn parse_rung<It>( &mut self, tokens: &mut Peekable<LadderTypeLexer<It>> ) -> Result<TypeTerm, ParseError>
+    fn parse_rung<It>(&mut self, tokens: &mut Peekable<LadderTypeLexer<It>>) -> Result<TypeTerm, ParseError>
     where It: Iterator<Item = char>
     {
         match tokens.next() {
@@ -79,8 +78,8 @@ impl TypeDict {
             None => Err(ParseError::UnexpectedEnd)
         }
     }
-    
-    fn parse_partial<It>( &mut self, tokens: &mut Peekable<LadderTypeLexer<It>> ) -> Result<TypeTerm, ParseError>
+
+    fn parse_ladder<It>(&mut self, tokens: &mut Peekable<LadderTypeLexer<It>>) -> Result<TypeTerm, ParseError>
     where It: Iterator<Item = char>
     {
         let mut rungs = Vec::new();
@@ -119,22 +118,6 @@ impl TypeDict {
             _ => Ok(TypeTerm::Ladder(rungs)),
         }
     }
-
-    pub fn parse<It>( &mut self, tokens: &mut Peekable<LadderTypeLexer<It>> ) -> Result<TypeTerm, ParseError>
-    where It: Iterator<Item = char>
-    {
-        match self.parse_partial(tokens) {
-            Ok(t) => {
-                if let Some(_tok) = tokens.peek() {
-                    Err(ParseError::UnexpectedToken)
-                } else {
-                    Ok(t)
-                }
-            }
-            Err(err) => Err(err)
-        }
-    }
 }
 
 //<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>\\
-
diff --git a/src/test/curry.rs b/src/test/curry.rs
index 8ad1cdf..41575b2 100644
--- a/src/test/curry.rs
+++ b/src/test/curry.rs
@@ -7,51 +7,55 @@ use {
 
 #[test]
 fn test_curry() {
+    let mut dict = TypeDict::new();
+
     assert_eq!(
-        TypeTerm::from_str("<A B C>").unwrap().curry(),
-        TypeTerm::from_str("<<A B> C>").unwrap()
+        dict.parse("<A B C>").unwrap().curry(),
+        dict.parse("<<A B> C>").unwrap()
     );
     assert_eq!(
-        TypeTerm::from_str("<A B C D>").unwrap().curry(),
-        TypeTerm::from_str("<<<A B> C> D>").unwrap()
+        dict.parse("<A B C D>").unwrap().curry(),
+        dict.parse("<<<A B> C> D>").unwrap()
     );
     assert_eq!(
-        TypeTerm::from_str("<A B C D E F G H I J K>").unwrap().curry(),
-        TypeTerm::from_str("<<<<<<<<<<A B> C> D> E> F> G> H> I> J> K>").unwrap()
+        dict.parse("<A B C D E F G H I J K>").unwrap().curry(),
+        dict.parse("<<<<<<<<<<A B> C> D> E> F> G> H> I> J> K>").unwrap()
     );
 
     assert_eq!(
-        TypeTerm::from_str("<A~X B C>").unwrap().curry(),
-        TypeTerm::from_str("<<A~X B> C>").unwrap()
+        dict.parse("<A~X B C>").unwrap().curry(),
+        dict.parse("<<A~X B> C>").unwrap()
     );
     assert_eq!(
-        TypeTerm::from_str("<A B C~Y~Z> ~ K").unwrap().curry(),
-        TypeTerm::from_str("< <A B> C~Y~Z > ~ K").unwrap()
+        dict.parse("<A B C~Y~Z> ~ K").unwrap().curry(),
+        dict.parse("< <A B> C~Y~Z > ~ K").unwrap()
     );
 }
 
 #[test]
 fn test_decurry() {
+    let mut dict = TypeDict::new();
+
     assert_eq!(
-        TypeTerm::from_str("<<A B> C>").unwrap().decurry(),
-        TypeTerm::from_str("<A B C>").unwrap()
+        dict.parse("<<A B> C>").unwrap().decurry(),
+        dict.parse("<A B C>").unwrap()
     );
     assert_eq!(
-        TypeTerm::from_str("<<<A B> C> D>").unwrap().decurry(),
-        TypeTerm::from_str("<A B C D>").unwrap(),
+        dict.parse("<<<A B> C> D>").unwrap().decurry(),
+        dict.parse("<A B C D>").unwrap(),
     );
     assert_eq!(
-        TypeTerm::from_str("<<<<<<<<<<A B> C> D> E> F> G> H> I> J> K>").unwrap().decurry(),
-        TypeTerm::from_str("<A B C D E F G H I J K>").unwrap()
+        dict.parse("<<<<<<<<<<A B> C> D> E> F> G> H> I> J> K>").unwrap().decurry(),
+        dict.parse("<A B C D E F G H I J K>").unwrap()
     );
     
     assert_eq!(
-        TypeTerm::from_str("<<A~X B> C>").unwrap().decurry(),
-        TypeTerm::from_str("<A~X B C>").unwrap()
+        dict.parse("<<A~X B> C>").unwrap().decurry(),
+        dict.parse("<A~X B C>").unwrap()
     );
     assert_eq!(
-        TypeTerm::from_str("<<A~X B> C~Y>~K").unwrap().decurry(),
-        TypeTerm::from_str("<A~X B C~Y> ~K").unwrap()
+        dict.parse("<<A~X B> C~Y>~K").unwrap().decurry(),
+        dict.parse("<A~X B C~Y> ~K").unwrap()
     );
 }
 
diff --git a/src/test/parser.rs b/src/test/parser.rs
index 41fd800..273232b 100644
--- a/src/test/parser.rs
+++ b/src/test/parser.rs
@@ -10,7 +10,7 @@ use {
 fn test_parser_id() {
     assert_eq!(
         Ok(TypeTerm::TypeID(TypeID::Fun(0))),
-        TypeTerm::from_str("A")
+        TypeDict::new().parse("A")
     );
 }
 
@@ -18,7 +18,7 @@ fn test_parser_id() {
 fn test_parser_num() {
     assert_eq!(
         Ok(TypeTerm::Num(1234)),
-        TypeTerm::from_str("1234")
+        TypeDict::new().parse("1234")
     );
 }
 
@@ -26,21 +26,21 @@ fn test_parser_num() {
 fn test_parser_char() {
     assert_eq!(
         Ok(TypeTerm::Char('x')),
-        TypeTerm::from_str("'x'")
+        TypeDict::new().parse("'x'")
     );
 }
 
 #[test]
 fn test_parser_app() {
     assert_eq!(
-        TypeTerm::from_str("<A B>"),
+        TypeDict::new().parse("<A B>"),
         Ok(TypeTerm::App(vec![
             TypeTerm::TypeID(TypeID::Fun(0)),
             TypeTerm::TypeID(TypeID::Fun(1)),
         ]))
     );
     assert_eq!(
-        TypeTerm::from_str("<A B C>"),
+        TypeDict::new().parse("<A B C>"),
         Ok(TypeTerm::App(vec![
             TypeTerm::TypeID(TypeID::Fun(0)),
             TypeTerm::TypeID(TypeID::Fun(1)),
@@ -52,7 +52,7 @@ fn test_parser_app() {
 #[test]
 fn test_parser_unexpected_close() {
     assert_eq!(
-        TypeTerm::from_str(">"),
+        TypeDict::new().parse(">"),
         Err(ParseError::UnexpectedClose)
     );
 }
@@ -60,7 +60,7 @@ fn test_parser_unexpected_close() {
 #[test]
 fn test_parser_unexpected_token() {
     assert_eq!(
-        TypeTerm::from_str("A B"),
+        TypeDict::new().parse("A B"),
         Err(ParseError::UnexpectedToken)
     );
 }
@@ -68,14 +68,14 @@ fn test_parser_unexpected_token() {
 #[test]
 fn test_parser_ladder() {
     assert_eq!(
-        TypeTerm::from_str("A~B"),
+        TypeDict::new().parse("A~B"),
         Ok(TypeTerm::Ladder(vec![
             TypeTerm::TypeID(TypeID::Fun(0)),
             TypeTerm::TypeID(TypeID::Fun(1)),
         ]))
     );
     assert_eq!(
-        TypeTerm::from_str("A~B~C"),
+        TypeDict::new().parse("A~B~C"),
         Ok(TypeTerm::Ladder(vec![
             TypeTerm::TypeID(TypeID::Fun(0)),
             TypeTerm::TypeID(TypeID::Fun(1)),
@@ -87,7 +87,7 @@ fn test_parser_ladder() {
 #[test]
 fn test_parser_ladder_outside() {
     assert_eq!(
-        TypeTerm::from_str("<A B>~C"),
+        TypeDict::new().parse("<A B>~C"),
         Ok(TypeTerm::Ladder(vec![
             TypeTerm::App(vec![
                 TypeTerm::TypeID(TypeID::Fun(0)),
@@ -101,7 +101,7 @@ fn test_parser_ladder_outside() {
 #[test]
 fn test_parser_ladder_inside() {
     assert_eq!(
-        TypeTerm::from_str("<A B~C>"),
+        TypeDict::new().parse("<A B~C>"),
         Ok(TypeTerm::App(vec![
             TypeTerm::TypeID(TypeID::Fun(0)),
             TypeTerm::Ladder(vec![
@@ -115,7 +115,7 @@ fn test_parser_ladder_inside() {
 #[test]
 fn test_parser_ladder_between() {
     assert_eq!(
-        TypeTerm::from_str("<A B~<C D>>"),
+        TypeDict::new().parse("<A B~<C D>>"),
         Ok(TypeTerm::App(vec![
             TypeTerm::TypeID(TypeID::Fun(0)),
             TypeTerm::Ladder(vec![
@@ -133,7 +133,7 @@ fn test_parser_ladder_between() {
 #[test]
 fn test_parser_ladder_large() {
     assert_eq!(
-        TypeTerm::from_str(
+        TypeDict::new().parse(
             "<Seq Date
                   ~<TimeSince UnixEpoch>
                   ~<Duration Seconds>