From d353c1623aff57bf863602f079fd19ad70b8e18e Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Thu, 13 Jul 2023 23:02:12 -0400
Subject: [PATCH] Implement the angle link parser.

---
 src/parser/angle_link.rs | 49 +++++++++++++++++++++++++++++++++++++---
 src/parser/plain_link.rs |  6 ++---
 2 files changed, 49 insertions(+), 6 deletions(-)

diff --git a/src/parser/angle_link.rs b/src/parser/angle_link.rs
index 94e0a9a..1a79ebe 100644
--- a/src/parser/angle_link.rs
+++ b/src/parser/angle_link.rs
@@ -1,10 +1,53 @@
+use nom::bytes::complete::tag;
+use nom::character::complete::anychar;
+use nom::combinator::peek;
+use nom::combinator::recognize;
+use nom::multi::many_till;
+
 use super::Context;
 use crate::error::Res;
-use crate::parser::util::not_yet_implemented;
+use crate::parser::exiting::ExitClass;
+use crate::parser::parser_context::ContextElement;
+use crate::parser::parser_context::ExitMatcherNode;
+use crate::parser::parser_with_context::parser_with_context;
+use crate::parser::plain_link::protocol;
+use crate::parser::util::exit_matcher_parser;
+use crate::parser::util::get_consumed;
 use crate::parser::AngleLink;
 
 #[tracing::instrument(ret, level = "debug")]
 pub fn angle_link<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, AngleLink<'s>> {
-    not_yet_implemented()?;
-    todo!();
+    let (remaining, _) = tag("<")(input)?;
+    let (remaining, proto) = protocol(context, remaining)?;
+    let (remaining, _separator) = tag(":")(remaining)?;
+    let (remaining, path) = path_angle(context, remaining)?;
+    let (remaining, _) = tag(">")(remaining)?;
+    let source = get_consumed(input, remaining);
+    Ok((
+        remaining,
+        AngleLink {
+            source,
+            link_type: proto,
+            path,
+        },
+    ))
+}
+
+#[tracing::instrument(ret, level = "debug")]
+fn path_angle<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, &'s str> {
+    let parser_context =
+        context.with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {
+            class: ExitClass::Beta,
+            exit_matcher: &path_angle_end,
+        }));
+
+    let exit_matcher = parser_with_context!(exit_matcher_parser)(&parser_context);
+
+    let (remaining, path) = recognize(many_till(anychar, peek(exit_matcher)))(input)?;
+    Ok((remaining, path))
+}
+
+#[tracing::instrument(ret, level = "debug")]
+fn path_angle_end<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, &'s str> {
+    tag(">")(input)
 }
diff --git a/src/parser/plain_link.rs b/src/parser/plain_link.rs
index 4b2c626..b5d97fc 100644
--- a/src/parser/plain_link.rs
+++ b/src/parser/plain_link.rs
@@ -42,7 +42,7 @@ pub fn plain_link<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s s
 }
 
 #[tracing::instrument(ret, level = "debug")]
-pub fn pre<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, ()> {
+fn pre<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, ()> {
     let document_root = context.get_document_root().unwrap();
     let preceding_character = get_one_before(document_root, input)
         .map(|slice| slice.chars().next())
@@ -62,7 +62,7 @@ pub fn pre<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, ()>
 }
 
 #[tracing::instrument(ret, level = "debug")]
-pub fn post<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, ()> {
+fn post<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, ()> {
     let (remaining, _) = alt((eof, recognize(none_of(WORD_CONSTITUENT_CHARACTERS))))(input)?;
     Ok((remaining, ()))
 }
@@ -103,7 +103,7 @@ pub fn protocol<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str
 }
 
 #[tracing::instrument(ret, level = "debug")]
-pub fn path_plain<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, &'s str> {
+fn path_plain<'r, 's>(context: Context<'r, 's>, input: &'s str) -> Res<&'s str, &'s str> {
     // TODO: "optionally containing parenthesis-wrapped non-whitespace non-bracket substrings up to a depth of two. The string must end with either a non-punctation non-whitespace character, a forwards slash, or a parenthesis-wrapped substring"
     let parser_context =
         context.with_additional_node(ContextElement::ExitMatcherNode(ExitMatcherNode {