feat: and run and and_then parser.

src/parser.rs

@@ -2,8 +2,8 @@ mod modified_parsers;
 mod primitive_parsers;
 
 use crate::parser::modified_parsers::{
-    BindParser, ConvertParser, LitervalCountParser, LitervalParser, LookAheadParser, MapParser,
-    NextParser, OptionalParser, ReverseParser, TryParser,
+    AndThenParser, BindParser, ConvertParser, LitervalCountParser, LitervalParser, LookAheadParser,
+    MapParser, NextParser, OptionalParser, ReverseParser, RunParser, TryParser,
 };
 use crate::parser::primitive_parsers::{
     AnyParser, FailParser, FailWithMessageParser, SatifiedMapParser, SatisfyParser, SkipParser,
@@ -33,6 +33,13 @@ impl<'a, TToken: Debug> FailedParserResult<'a, TToken> {
         }
     }
 
+    pub fn new_with_error(input: &'a [TToken], err: anyhow::Error) -> Self {
+        Self {
+            input,
+            message: format!("{}", err),
+        }
+    }
+
     pub fn message(&self) -> &str {
         self.message.as_str()
     }
@@ -207,6 +214,29 @@ where
     {
         OptionalParser { parser: self }
     }
+
+    fn run<F>(self, action: F) -> RunParser<Self, F>
+    where
+        Self: Sized,
+        F: Fn(&T) -> (),
+    {
+        RunParser {
+            parser: self,
+            action,
+        }
+    }
+
+    fn and_then<TResult, F>(self, mapper: F) -> AndThenParser<Self, F, T>
+    where
+        Self: Sized,
+        F: Fn(T) -> anyhow::Result<TResult>,
+    {
+        AndThenParser {
+            parser: self,
+            mapper,
+            phantom_data: PhantomData,
+        }
+    }
 }
 
 impl<'a, TToken, T: 'a, TContext, F> Parser<'a, TToken, T, TContext> for F

src/parser/modified_parsers.rs

@@ -261,13 +261,68 @@ where
     }
 }
 
+pub struct RunParser<P, F> {
+    pub(crate) parser: P,
+    pub(crate) action: F,
+}
+
+impl<'a, TToken, T: 'a, TContext, P, F> Parser<'a, TToken, T, TContext> for RunParser<P, F>
+where
+    TToken: Debug + Clone,
+    P: Parser<'a, TToken, T, TContext>,
+    F: Fn(&T) -> (),
+{
+    fn parse(
+        &self,
+        context: Rc<RefCell<ParserContext<TToken, TContext>>>,
+        input: &'a [TToken],
+    ) -> ParserResult<'a, TToken, T> {
+        match self.parser.parse(context, input) {
+            Ok(r) => {
+                (self.action)(&r.1);
+
+                Ok(r)
+            }
+            r => r,
+        }
+    }
+}
+
+pub struct AndThenParser<P, F, T> {
+    pub(crate) parser: P,
+    pub(crate) mapper: F,
+    pub(crate) phantom_data: PhantomData<T>,
+}
+
+impl<'a, TToken, T: 'a, TResult: 'a, TContext, P, F> Parser<'a, TToken, TResult, TContext>
+    for AndThenParser<P, F, T>
+where
+    TToken: Debug + Clone,
+    P: Parser<'a, TToken, T, TContext>,
+    F: Fn(T) -> anyhow::Result<TResult>,
+{
+    fn parse(
+        &self,
+        context: Rc<RefCell<ParserContext<TToken, TContext>>>,
+        input: &'a [TToken],
+    ) -> ParserResult<'a, TToken, TResult> {
+        match self.parser.parse(context, input) {
+            Ok((i, r)) => match (self.mapper)(r) {
+                Ok(result) => Ok((i, result)),
+                Err(err) => Err(FailedParserResult::new_with_error(i, err)),
+            },
+            Err(r) => Err(r),
+        }
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
     use crate::parser::{
         failed_parser_test_helper, parser_test_helper, satisfy, take, FailedParserResult,
     };
-    use crate::text::char_parser;
+    use crate::text::{char_parser, char_satisfy};
 
     #[test]
     fn map_test() {
@@ -447,4 +502,23 @@ mod test {
             char_parser('a').optional().parse(c, i)
         });
     }
+
+    #[test]
+    fn run_test() {
+        parser_test_helper(ParserContext::new_with_str("abc", ()), &'a', |c, i| {
+            char_parser('a').run(|c| assert_eq!(c, &'a')).parse(c, i)
+        })
+    }
+
+    #[test]
+    fn and_then_test() {
+        parser_test_helper(ParserContext::new_with_str("123", ()), &1, |c, i| {
+            char_satisfy(char::is_ascii_digit)
+                .and_then(|c| {
+                    let word = c.to_string();
+                    Ok(i32::from_str_radix(word.as_str(), 10)?)
+                })
+                .parse(c, i)
+        });
+    }
 }