From 25b8c80d4ee82133892cc0c06171b60eef60857e Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Sat, 2 Sep 2023 18:40:01 -0400
Subject: [PATCH] Add default constructors.

---
 src/lib.rs                   |  1 +
 src/parser/document.rs       |  4 ++--
 src/parser/parser_context.rs | 42 +++++++++++++++++++++++++++++++++++-
 3 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 513e5c9..70249dd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,6 @@
 #![feature(round_char_boundary)]
 #![feature(exit_status_error)]
+#![feature(trait_alias)]
 
 #[cfg(feature = "compare")]
 mod compare;
diff --git a/src/parser/document.rs b/src/parser/document.rs
index 760c6dc..1fc0dbd 100644
--- a/src/parser/document.rs
+++ b/src/parser/document.rs
@@ -18,6 +18,7 @@ use nom::multi::separated_list1;
 use nom::sequence::tuple;
 
 use super::element::Element;
+use super::list::List;
 use super::object::Object;
 use super::org_source::convert_error;
 use super::org_source::OrgSource;
@@ -35,7 +36,6 @@ use crate::parser::element_parser::element;
 use crate::parser::exiting::ExitClass;
 use crate::parser::object_parser::standard_set_object;
 use crate::parser::parser_context::ContextElement;
-use crate::parser::parser_context::ContextTree;
 use crate::parser::parser_context::ExitMatcherNode;
 use crate::parser::planning::planning;
 use crate::parser::property_drawer::property_drawer;
@@ -102,7 +102,7 @@ impl<'s> Source<'s> for Heading<'s> {
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
 #[allow(dead_code)]
 pub fn document(input: &str) -> Res<&str, Document> {
-    let initial_context: ContextTree<'_, '_> = ContextTree::new();
+    let initial_context = Context::default();
     let wrapped_input = OrgSource::new(input);
     let (remaining, document) = _document(&initial_context, wrapped_input)
         .map(|(rem, out)| (Into::<&str>::into(rem), out))
diff --git a/src/parser/parser_context.rs b/src/parser/parser_context.rs
index 35e3c57..1dce6e9 100644
--- a/src/parser/parser_context.rs
+++ b/src/parser/parser_context.rs
@@ -1,6 +1,10 @@
+use nom::combinator::eof;
+
 use super::list::List;
+use super::org_source::OrgSource;
 use super::DynContextMatcher;
 use super::Object;
+use crate::error::Res;
 use crate::parser::exiting::ExitClass;
 use crate::parser::list::ListType;
 
@@ -136,6 +140,12 @@ impl<'s> GlobalSettings<'s> {
     }
 }
 
+impl<'s> Default for GlobalSettings<'s> {
+    fn default() -> Self {
+        GlobalSettings::new()
+    }
+}
+
 #[derive(Debug)]
 pub struct Context<'r, 's> {
     global_settings: &'s GlobalSettings<'s>,
@@ -147,12 +157,22 @@ impl<'r, 's> Context<'r, 's> {
         global_settings: &'s GlobalSettings<'s>,
         tree: List<'r, ContextElement<'r, 's>>,
     ) -> Self {
-        Context {
+        Self {
             global_settings,
             tree,
         }
     }
 
+    pub fn document_context(global_settings: &'s GlobalSettings<'s>) -> Self {
+        Context::new(
+            global_settings,
+            List::new(ContextElement::ExitMatcherNode(ExitMatcherNode {
+                exit_matcher: &document_end,
+                class: ExitClass::Document,
+            })),
+        )
+    }
+
     pub fn push(&self, data: ContextElement<'r, 's>) -> Self {
         let new_tree = self.tree.push(data);
         Self {
@@ -161,3 +181,23 @@ impl<'r, 's> Context<'r, 's> {
         }
     }
 }
+
+impl<'r, 's> Default for Context<'r, 's> {
+    fn default() -> Self {
+        Context::new(
+            GlobalSettings::default(),
+            List::new(ContextElement::ExitMatcherNode(ExitMatcherNode {
+                exit_matcher: &document_end,
+                class: ExitClass::Document,
+            })),
+        )
+    }
+}
+
+#[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
+fn document_end<'r, 's>(
+    _context: Context<'r, 's>,
+    input: OrgSource<'s>,
+) -> Res<OrgSource<'s>, OrgSource<'s>> {
+    eof(input)
+}