From f2ddf6451ca91586d62b0a1740d9194f77eb3589 Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Thu, 24 Nov 2022 14:59:37 -0500
Subject: [PATCH] Mutable push.

---
 src/parser/nom_context.rs | 59 +++++++++++++++++++--------------------
 1 file changed, 28 insertions(+), 31 deletions(-)

diff --git a/src/parser/nom_context.rs b/src/parser/nom_context.rs
index 9254f27f..0cfa096e 100644
--- a/src/parser/nom_context.rs
+++ b/src/parser/nom_context.rs
@@ -7,41 +7,38 @@ use nom::error::VerboseError;
 use nom::IResult;
 use nom::Parser;
 
-// type ContextReference<'r, T> = Option<ContextLayer<'r, T>>;
-// type MatcherRef = dyn for<'s> FnMut(&'s str) -> IResult<&'s str, &'s str, VerboseError<&'s str>>;
+type Link<T> = Option<Box<Node<T>>>;
+type Matcher = dyn for<'s> Fn(&'s str) -> IResult<&'s str, &'s str, VerboseError<&'s str>>;
 
-// pub struct ContextLayer<'r, T> {
-//     data: T,
-//     parent: ContextReference<'r, T>,
-// }
+struct Node<T> {
+    elem: T,
+    next: Link<T>,
+}
 
-// pub struct TestContext<'r, T> {
-//     head: ContextReference<'r, T>,
-// }
+pub struct List<T> {
+    head: Link<T>,
+}
 
-// pub struct ContextData<'r> {
-//     fail_matcher: ChainBehavior<'r>,
-// }
+impl<T> List<T> {
+    pub fn new() -> Self {
+        List { head: None }
+    }
 
-// impl<'r> TestContext<'r, ContextData<'r>> {
-//     pub fn new() -> Self {
-//         TestContext { head: None }
-//     }
+    pub fn push(&mut self, element: T) {
+        let new_node = Box::new(Node {
+            elem: element,
+            next: self.head.take(),
+        });
 
-//     pub fn with_additional_fail_matcher<'subr>(
-//         &self,
-//         additional_fail_matcher: &'subr MatcherRef,
-//     ) -> TestContext<'subr, ContextData<'subr>> {
-//         // TestContext {
-//         //     head: Some(
+        self.head = Some(new_node);
+    }
+}
 
-//         //     )
-//         // }
-//         todo!()
-//     }
-// }
+struct ContextElement<'r> {
+    fail_matcher: ChainBehavior<'r>,
+}
 
-// enum ChainBehavior<'r> {
-//     AndParent(Option<&'r MatcherRef>),
-//     IgnoreParent(Option<&'r MatcherRef>),
-// }
+enum ChainBehavior<'r> {
+    AndParent(Option<&'r Matcher>),
+    IgnoreParent(Option<&'r Matcher>),
+}