2 files changed, 71 insertions, 0 deletions
diff --git a/src/util/mdx_collect.rs b/src/util/mdx_collect.rs
new file mode 100644
index 0000000..73ead51
--- /dev/null
+++ b/src/util/mdx_collect.rs
@@ -0,0 +1,70 @@
+//! Collect info for MDX.
+
+use crate::event::{Kind, Name, Point};
+use crate::tokenizer::Tokenizer;
+use crate::util::slice::{Position, Slice};
+use alloc::{string::String, vec, vec::Vec};
+
+pub type Location<'a> = (usize, &'a Point);
+
+pub struct Result<'a> {
+    pub start: &'a Point,
+    pub value: String,
+    pub locations: Vec<Location<'a>>,
+}
+
+pub fn collect<'a>(tokenizer: &'a Tokenizer, from: usize, names: &[Name]) -> Result<'a> {
+    let mut result = Result {
+        start: &tokenizer.events[from].point,
+        value: String::new(),
+        locations: vec![],
+    };
+    let mut index = from;
+    let mut acc = 0;
+
+    while index < tokenizer.events.len() {
+        if tokenizer.events[index].kind == Kind::Enter
+            && names.contains(&tokenizer.events[index].name)
+        {
+            // Include virtual spaces.
+            let value = Slice::from_position(
+                tokenizer.parse_state.bytes,
+                &Position {
+                    start: &tokenizer.events[index].point,
+                    end: &tokenizer.events[index + 1].point,
+                },
+            )
+            .serialize();
+            acc += value.len();
+            result.locations.push((acc, &tokenizer.events[index].point));
+            result.value.push_str(&value);
+        }
+
+        index += 1;
+    }
+
+    result
+}
+
+// Turn an index of `result.value` into a point in the whole document.
+pub fn place_to_point(result: &Result, place: usize) -> Point {
+    let mut index = 0;
+    let mut point = result.start;
+    let mut rest = place;
+
+    while index < result.locations.len() {
+        point = result.locations[index].1;
+
+        if result.locations[index].0 > place {
+            break;
+        }
+
+        rest = place - result.locations[index].0;
+        index += 1;
+    }
+
+    let mut point = point.clone();
+    point.column += rest;
+    point.index += rest;
+    point
+}
diff --git a/src/util/mod.rs b/src/util/mod.rs
index 2ea372c..6281356 100644
--- a/src/util/mod.rs
+++ b/src/util/mod.rs
@@ -6,6 +6,7 @@ pub mod decode_character_reference;
 pub mod edit_map;
 pub mod encode;
 pub mod gfm_tagfilter;
+pub mod mdx_collect;
 pub mod normalize_identifier;
 pub mod sanitize_uri;
 pub mod skip;