Add named parser

src/parser/boxed_parser.rs

@@ -20,6 +20,7 @@ where
             inner: Box::new(inner),
         }
     }
+
 }
 
 impl<'a, I: ParserInput, O, E> Parser<I, O, E> for BoxedParser<'a, I, O, E> {
@@ -30,4 +31,8 @@ impl<'a, I: ParserInput, O, E> Parser<I, O, E> for BoxedParser<'a, I, O, E> {
     fn bnf(&self) -> Option<Bnf> {
         self.inner.bnf()
     }
+
+    fn boxed<'b>(self) -> BoxedParser<'b, I, O, E> where Self: Sized + 'b {
+        self
+    }
 }

src/parser/mod.rs

@@ -1,9 +1,11 @@
 mod boxed_parser;
+mod named_parser;
 
 use crate::bnf::Bnf;
 use std::rc::Rc;
 
 pub use boxed_parser::BoxedParser;
+pub use named_parser::NamedParser;
 
 pub type ParseResult<I, O, E> = Result<(O, I), E>;
 
@@ -21,6 +23,10 @@ where
         None
     }
 
+    fn boxed<'a>(self) -> BoxedParser<'a, I, O, E> where Self: Sized + 'a {
+        BoxedParser::new(self)
+    }
+
     fn map<'a, F, O2>(self, map_fn: F) -> BoxedParser<'a, I, O2, E>
     where
         Self: Sized + 'a,
@@ -30,7 +36,7 @@ where
         O2: 'a,
         F: Fn(O) -> O2 + 'a,
     {
-        BoxedParser::new(crate::combinators::map(self, map_fn))
+        crate::combinators::map(self, map_fn).boxed()
     }
 
     fn to<'a, O2>(self, item: O2) -> BoxedParser<'a, I, O2, E>
@@ -53,7 +59,7 @@ where
         E: 'a,
         P: Parser<I, O2, E> + 'a,
     {
-        BoxedParser::new(crate::sequence::tuple2(self, next_parser))
+        crate::sequence::tuple2(self, next_parser).boxed()
     }
 
     fn ignore_then<'a, P, O2>(self, next_parser: P) -> BoxedParser<'a, I, O2, E>
@@ -65,7 +71,7 @@ where
         E: 'a,
         P: Parser<I, O2, E> + 'a,
     {
-        BoxedParser::new(crate::sequence::tuple2(self, next_parser))
+        crate::sequence::tuple2(self, next_parser)
             .map(|(_, next_output)| next_output)
     }
 
@@ -78,7 +84,7 @@ where
         E: 'a,
         P: Parser<I, O2, E> + 'a,
     {
-        BoxedParser::new(crate::sequence::tuple2(self, next_parser))
+        crate::sequence::tuple2(self, next_parser)
             .map(|(this_output, _)| this_output)
     }
 
@@ -122,7 +128,15 @@ where
         E: 'a,
         Self: Sized + 'a,
     {
-        BoxedParser::new(crate::combinators::optional(self))
+        crate::combinators::optional(self).boxed()
+    }
+
+    fn named<'a>(self, parser_name: &str) -> NamedParser<'a, I, O, E>
+    where
+        Self: Sized + 'a,
+        I: 'a,
+    {
+        NamedParser::new(self.boxed(), parser_name.to_string())
     }
 }
 

src/parser/named_parser.rs

@@ -0,0 +1,33 @@
+use crate::parser::{ParseResult, Parser, ParserInput};
+//use crate::bnf::Bnf;
+use super::boxed_parser::BoxedParser;
+
+pub struct NamedParser<'a, I, O, E>
+where
+    I: ParserInput,
+{
+    inner_parser: BoxedParser<'a, I, O, E>,
+    name: String,
+}
+
+impl<'a, I, O, E> NamedParser<'a, I, O, E>
+where
+    I: ParserInput,
+{
+    pub(super) fn new(inner_parser: BoxedParser<'a, I, O, E>, name: String) -> Self
+    where
+        I: 'a,
+    {
+        NamedParser { inner_parser, name }
+    }
+
+    pub fn get_name(&'a self) -> &'a str {
+        self.name.as_ref()
+    }
+}
+
+impl<'a, I: ParserInput, O, E> Parser<I, O, E> for NamedParser<'a, I, O, E> {
+    fn parse(&self, input: I) -> ParseResult<I, O, E> {
+        self.inner_parser.parse(input)
+    }
+}