From 6459cc64d097a4a88f471135202e09fe610a7639 Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Fri, 16 Dec 2022 00:47:33 -0500
Subject: [PATCH] I think thats all for context_many1. Just need to start using
 it.

---
 src/parser/combinator.rs  | 27 ++++++++++++++++-----------
 src/parser/list.rs        | 33 ++++++++++++++++++++++++++++++---
 src/parser/nom_context.rs |  7 +++++++
 3 files changed, 53 insertions(+), 14 deletions(-)

diff --git a/src/parser/combinator.rs b/src/parser/combinator.rs
index c281d483..58ea89b4 100644
--- a/src/parser/combinator.rs
+++ b/src/parser/combinator.rs
@@ -72,19 +72,24 @@ where
                 }
             }
         }
-        current_context
-            .iter_until(context)
-            .filter(|context_element| match context_element.get_data() {
-                ContextElement::PreviousElementNode(_) => true,
-                ContextElement::ExitMatcherNode(_) => false,
-                ContextElement::Context(_) => false,
-                ContextElement::StartOfParagraph => false,
-            });
-
-        // todo
-        todo!()
+        let elements: Vec<Token<'s>> = current_context
+            .into_iter_until(context)
+            .filter_map(|context_element| match context_element {
+                ContextElement::PreviousElementNode(elem) => Some(elem.element),
+                ContextElement::ExitMatcherNode(_) => None,
+                ContextElement::Context(_) => None,
+                ContextElement::StartOfParagraph => None,
+            })
+            .collect();
+        if elements.is_empty() {
+            if let Some(err) = err {
+                err?;
+            }
+        }
+        Ok((i, elements))
     }
 }
+
 pub fn context_many_till<'r, 's, I, O, E, F, M, T>(
     context: Context<'r, 's>,
     mut many_matcher: M,
diff --git a/src/parser/list.rs b/src/parser/list.rs
index 0a9b5c4a..ccf6687b 100644
--- a/src/parser/list.rs
+++ b/src/parser/list.rs
@@ -27,7 +27,7 @@ impl<T> Node<T> {
 }
 
 // TODO: This Debug is only needed because of the try_unwrap+expect
-impl<T: Debug> List<T> {
+impl<T> List<T> {
     pub fn new() -> Self {
         List { head: None }
     }
@@ -45,8 +45,10 @@ impl<T: Debug> List<T> {
         match self.head.take() {
             None => (None, List::new()),
             Some(popped_node) => {
-                let extracted_node =
-                    Rc::try_unwrap(popped_node).expect("TODO I should handle this better");
+                let extracted_node = match Rc::try_unwrap(popped_node) {
+                    Ok(node) => node,
+                    Err(e) => panic!("try_unwrap failed on Rc in pop_front on List."),
+                };
                 (
                     Some(extracted_node.data),
                     List {
@@ -91,6 +93,13 @@ impl<T: Debug> List<T> {
             stop: &other.head,
         }
     }
+
+    pub fn into_iter_until<'a>(self, other: &'a List<T>) -> impl Iterator<Item = T> + 'a {
+        NodeIntoIterUntil {
+            position: self,
+            stop: &other,
+        }
+    }
 }
 
 pub struct NodeIter<'a, T> {
@@ -144,3 +153,21 @@ impl<'a, T> Iterator for NodeIterUntil<'a, T> {
         Some(return_value)
     }
 }
+
+pub struct NodeIntoIterUntil<'a, T> {
+    position: List<T>,
+    stop: &'a List<T>,
+}
+
+impl<'a, T> Iterator for NodeIntoIterUntil<'a, T> {
+    type Item = T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.position.ptr_eq(self.stop) {
+            return None;
+        }
+        let (popped_element, new_position) = self.position.pop_front();
+        self.position = new_position;
+        popped_element
+    }
+}
diff --git a/src/parser/nom_context.rs b/src/parser/nom_context.rs
index c2ea28fc..632dc572 100644
--- a/src/parser/nom_context.rs
+++ b/src/parser/nom_context.rs
@@ -50,6 +50,13 @@ impl<'r, 's> ContextTree<'r, 's> {
         self.tree.iter_until(&other.tree)
     }
 
+    pub fn into_iter_until<'x: 'r>(
+        self,
+        other: &'x ContextTree<'x, 's>,
+    ) -> impl Iterator<Item = ContextElement<'r, 's>> {
+        self.tree.into_iter_until(&other.tree)
+    }
+
     pub fn check_exit_matcher(
         &'r self,
         i: &'s str,