Migrated LazyParser to MapDecorator

Author: ngeor

rusty_pc/src/lazy.rs

@@ -1,3 +1,4 @@
+use crate::map_decorator::{MapDecorator, MapDecoratorMarker};
 use crate::{InputTrait, Parser};
 
 pub fn lazy<I, C, F, P>(factory: F) -> impl Parser<I, C, Output = P::Output, Error = P::Error>
@@ -17,28 +18,29 @@ struct LazyParser<F, P> {
     parser_holder: Option<P>,
 }
 
-impl<I, C, F, P> Parser<I, C> for LazyParser<F, P>
+impl<I, C, F, P> MapDecorator<I, C> for LazyParser<F, P>
 where
     F: Fn() -> P,
     I: InputTrait,
     P: Parser<I, C>,
 {
+    type OriginalOutput = P::Output;
     type Output = P::Output;
     type Error = P::Error;
 
-    fn parse(&mut self, input: &mut I) -> Result<Self::Output, Self::Error> {
-        match self.parser_holder.as_mut() {
-            Some(parser) => parser.parse(input),
-            None => {
-                let mut parser = (self.factory)();
-                let result = parser.parse(input);
-                self.parser_holder = Some(parser);
-                result
-            }
+    fn decorated(
+        &mut self,
+    ) -> &mut impl Parser<I, C, Output = Self::OriginalOutput, Error = Self::Error> {
+        if self.parser_holder.is_none() {
+            let parser = (self.factory)();
+            self.parser_holder = Some(parser);
         }
+        self.parser_holder.as_mut().unwrap()
     }
 
-    fn set_context(&mut self, _ctx: &C) {
-        unimplemented!()
+    fn map_ok(&self, ok: Self::OriginalOutput) -> Result<Self::Output, Self::Error> {
+        Ok(ok)
     }
 }
+
+impl<F, P> MapDecoratorMarker for LazyParser<F, P> {}