Make stuff more elegant

3 files changed, 58 insertions, 71 deletions

diff --git a/src/source.rs b/src/source.rs
index 069edd29..2d18ece3 100644
--- a/src/source.rs
+++ b/src/source.rs
@@ -2,7 +2,7 @@
 
 use std::collections::HashMap;
 use std::io;
-use std::ops::Range;
+use std::ops::{Not, Range};
 use std::path::{Path, PathBuf};
 use std::rc::Rc;
 
@@ -10,9 +10,9 @@ use serde::{Deserialize, Serialize};
 
 use crate::diag::TypResult;
 use crate::loading::{FileHash, Loader};
-use crate::parse::{is_newline, parse, Scanner};
+use crate::parse::{is_newline, parse, parse_block, Scanner};
 use crate::syntax::ast::Markup;
-use crate::syntax::{self, Category, GreenNode, RedNode};
+use crate::syntax::{self, Category, GreenNode, NodeKind, RedNode, Span};
 use crate::util::PathExt;
 
 #[cfg(feature = "codespan-reporting")]
@@ -284,37 +284,28 @@ impl SourceFile {
             .extend(newlines(&self.src[start ..]).map(|idx| start + idx));
 
         // Update the root node.
-        #[cfg(not(feature = "parse-cache"))]
-        {
-            self.root = parse(&self.src);
-        }
-
-        #[cfg(feature = "parse-cache")]
-        {
-            let insertion_span = replace.into_span(self.id);
-            let incremental_target =
-                Rc::make_mut(&mut self.root).incremental_parent(insertion_span);
-
-            match incremental_target {
-                Some((child_idx, parent, offset)) => {
-                    let child = &parent.children()[child_idx];
-                    let src = &self.src[offset .. offset + child.len()];
-                    let parse_res = match child.kind() {
-                        NodeKind::Markup => Some(parse(src)),
-                        _ => parse_block(src),
-                    }
-                    .and_then(|x| x.data().erroneous().not().then(|| x));
-
-                    if let Some(parse_res) = parse_res {
-                        parent.replace_child(child_idx, parse_res);
-                    } else {
-                        self.root = parse(&self.src);
-                    }
+        let insertion_span = Span::new(self.id, replace.start, replace.end);
+        let incremental_target =
+            Rc::make_mut(&mut self.root).incremental_parent(insertion_span);
+
+        match incremental_target {
+            Some((child, offset)) => {
+                let src = &self.src[offset .. offset + child.len()];
+                let parse_res = match child.kind() {
+                    NodeKind::Markup => Some(parse(src)),
+                    _ => parse_block(src),
                 }
-                None => {
+                .and_then(|x| x.erroneous.not().then(|| x));
+
+                if let Some(parse_res) = parse_res {
+                    *child = Rc::try_unwrap(parse_res).unwrap();
+                } else {
                     self.root = parse(&self.src);
                 }
             }
+            None => {
+                self.root = parse(&self.src);
+            }
         }
     }
 
@@ -405,6 +396,7 @@ impl<'a> Files<'a> for SourceStore {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::syntax::Green;
 
     const TEST: &str = "ä\tcde\nf💛g\r\nhi\rjkl";
 
diff --git a/src/syntax/mod.rs b/src/syntax/mod.rs
index b0911c63..5da690ab 100644
--- a/src/syntax/mod.rs
+++ b/src/syntax/mod.rs
@@ -98,7 +98,7 @@ pub struct GreenNode {
     /// This node's children, losslessly make up this node.
     children: Vec<Green>,
     /// Whether this node or any of its children are erroneous.
-    erroneous: bool,
+    pub erroneous: bool,
 }
 
 impl GreenNode {
@@ -148,12 +148,9 @@ impl GreenNode {
         self.data().len()
     }
 
-    /// Find the parent of the deepest incremental-safe node and the index of
-    /// the found child.
-    pub fn incremental_parent(
-        &mut self,
-        span: Span,
-    ) -> Option<(usize, &mut GreenNode, usize)> {
+    /// Find the deepest incremental-safe node and its offset in the source
+    /// code.
+    pub fn incremental_parent(&mut self, span: Span) -> Option<(&mut GreenNode, usize)> {
         self.incremental_parent_internal(span, 0)
     }
 
@@ -161,10 +158,8 @@ impl GreenNode {
         &mut self,
         span: Span,
         mut offset: usize,
-    ) -> Option<(usize, &mut GreenNode, usize)> {
-        let x = unsafe { &mut *(self as *mut _) };
-
-        for (i, child) in self.children.iter_mut().enumerate() {
+    ) -> Option<(&mut GreenNode, usize)> {
+        for child in self.children.iter_mut() {
             match child {
                 Green::Token(n) => {
                     if offset < span.start {
@@ -187,15 +182,15 @@ impl GreenNode {
                         && span.end > offset
                     {
                         // the node is within the span.
-                        if n.kind().is_incremental_safe() {
-                            let res =
-                                Rc::make_mut(n).incremental_parent_internal(span, offset);
+                        let safe = n.kind().is_incremental_safe();
+                        let mut_n = Rc::make_mut(n);
+                        if safe {
+                            let res = mut_n.incremental_parent_internal(span, offset);
                             if res.is_none() {
-                                return Some((i, x, offset));
+                                return Some((mut_n, offset));
                             }
                         } else {
-                            return Rc::make_mut(n)
-                                .incremental_parent_internal(span, offset);
+                            return mut_n.incremental_parent_internal(span, offset);
                         }
                     } else {
                         // the node is overlapping or after after the span; nodes are
@@ -208,11 +203,6 @@ impl GreenNode {
 
         return None;
     }
-
-    /// Replace one of the node's children.
-    pub fn replace_child(&mut self, index: usize, child: impl Into<Green>) {
-        self.children[index] = child.into();
-    }
 }
 
 impl From<GreenNode> for Green {
@@ -352,7 +342,7 @@ impl Debug for RedNode {
     }
 }
 
-/// A borrowed wrapper for a green node with span information.
+/// A borrowed wrapper for a [`GreenNode`] with span information.
 ///
 /// Borrowed variant of [`RedNode`]. Can be [cast](Self::cast) to an AST node.
 #[derive(Copy, Clone, PartialEq)]
@@ -387,6 +377,26 @@ impl<'a> RedRef<'a> {
         Span::new(self.id, self.offset, self.offset + self.green.len())
     }
 
+    /// Whether the node or its children contain an error.
+    pub fn erroneous(self) -> bool {
+        self.green.erroneous()
+    }
+
+    /// The node's children.
+    pub fn children(self) -> Children<'a> {
+        let children = match &self.green {
+            Green::Node(node) => node.children(),
+            Green::Token(_) => &[],
+        };
+
+        Children {
+            id: self.id,
+            iter: children.iter(),
+            front: self.offset,
+            back: self.offset + self.len(),
+        }
+    }
+
     /// The error messages for this node and its descendants.
     pub fn errors(self) -> Vec<Error> {
         if !self.green.erroneous() {
@@ -419,21 +429,6 @@ impl<'a> RedRef<'a> {
         T::from_red(self)
     }
 
-    /// The node's children.
-    pub fn children(self) -> Children<'a> {
-        let children = match &self.green {
-            Green::Node(node) => node.children(),
-            Green::Token(_) => &[],
-        };
-
-        Children {
-            id: self.id,
-            iter: children.iter(),
-            front: self.offset,
-            back: self.offset + self.len(),
-        }
-    }
-
     /// Get the first child that can cast to some AST type.
     pub fn cast_first_child<T: TypedNode>(self) -> Option<T> {
         self.children().find_map(RedRef::cast)
diff --git a/src/syntax/span.rs b/src/syntax/span.rs
index a707d3d9..430d5f1d 100644
--- a/src/syntax/span.rs
+++ b/src/syntax/span.rs
@@ -127,12 +127,12 @@ impl Span {
 
     /// Create a new span with n characters inserted inside of this span.
     pub fn inserted(mut self, other: Self, n: usize) -> Self {
-        if !self.contains(other.start) || !self.contains(other.end) {
+        if !self.surrounds(other) {
             panic!();
         }
 
-        let len_change = (n as isize - other.len() as isize) as usize;
-        self.end += len_change;
+        let len_change = n as isize - other.len() as isize;
+        self.end += len_change as usize;
         self
     }