Skip to content

Support insertion in SyntaxRewriter #6347

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Oct 26, 2020
Merged

Support insertion in SyntaxRewriter #6347

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
aca2735
Support insertion in SyntaxRewriter
Veykril Oct 24, 2020
45860d5
Remove InsertPos::Before variant in Syntax Rewriter
Veykril Oct 24, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
165 changes: 141 additions & 24 deletions crates/syntax/src/algo.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -289,11 +289,19 @@ fn _replace_children(
with_children(parent, new_children)
}

#[derive(Debug, PartialEq, Eq, Hash)]
enum InsertPos {
FirstChildOf(SyntaxNode),
// Before(SyntaxElement),
After(SyntaxElement),
}

#[derive(Default)]
pub struct SyntaxRewriter<'a> {
f: Option<Box<dyn Fn(&SyntaxElement) -> Option<SyntaxElement> + 'a>>,
//FIXME: add debug_assertions that all elements are in fact from the same file.
replacements: FxHashMap<SyntaxElement, Replacement>,
insertions: IndexMap<InsertPos, Vec<SyntaxElement>>,
}

impl fmt::Debug for SyntaxRewriter<'_> {
Expand All @@ -304,13 +312,96 @@ impl fmt::Debug for SyntaxRewriter<'_> {

impl<'a> SyntaxRewriter<'a> {
pub fn from_fn(f: impl Fn(&SyntaxElement) -> Option<SyntaxElement> + 'a) -> SyntaxRewriter<'a> {
SyntaxRewriter { f: Some(Box::new(f)), replacements: FxHashMap::default() }
SyntaxRewriter {
f: Some(Box::new(f)),
replacements: FxHashMap::default(),
insertions: IndexMap::default(),
}
}
pub fn delete<T: Clone + Into<SyntaxElement>>(&mut self, what: &T) {
let what = what.clone().into();
let replacement = Replacement::Delete;
self.replacements.insert(what, replacement);
}
pub fn insert_before<T: Clone + Into<SyntaxElement>, U: Clone + Into<SyntaxElement>>(
&mut self,
before: &T,
what: &U,
) {
let before = before.clone().into();
let pos = match before.prev_sibling_or_token() {
Some(sibling) => InsertPos::After(sibling),
None => match before.parent() {
Some(parent) => InsertPos::FirstChildOf(parent),
None => return,
},
};
self.insertions.entry(pos).or_insert_with(Vec::new).push(what.clone().into());
}
pub fn insert_after<T: Clone + Into<SyntaxElement>, U: Clone + Into<SyntaxElement>>(
&mut self,
after: &T,
what: &U,
) {
self.insertions
.entry(InsertPos::After(after.clone().into()))
.or_insert_with(Vec::new)
.push(what.clone().into());
}
pub fn insert_as_first_child<T: Clone + Into<SyntaxNode>, U: Clone + Into<SyntaxElement>>(
&mut self,
parent: &T,
what: &U,
) {
self.insertions
.entry(InsertPos::FirstChildOf(parent.clone().into()))
.or_insert_with(Vec::new)
.push(what.clone().into());
}
pub fn insert_many_before<
T: Clone + Into<SyntaxElement>,
U: IntoIterator<Item = SyntaxElement>,
>(
&mut self,
before: &T,
what: U,
) {
let before = before.clone().into();
let pos = match before.prev_sibling_or_token() {
Some(sibling) => InsertPos::After(sibling),
None => match before.parent() {
Some(parent) => InsertPos::FirstChildOf(parent),
None => return,
},
};
self.insertions.entry(pos).or_insert_with(Vec::new).extend(what);
}
pub fn insert_many_after<
T: Clone + Into<SyntaxElement>,
U: IntoIterator<Item = SyntaxElement>,
>(
&mut self,
after: &T,
what: U,
) {
self.insertions
.entry(InsertPos::After(after.clone().into()))
.or_insert_with(Vec::new)
.extend(what);
}
pub fn insert_many_as_first_children<
T: Clone + Into<SyntaxNode>,
U: IntoIterator<Item = SyntaxElement>,
>(
&mut self,
parent: &T,
what: U,
) {
self.insertions
.entry(InsertPos::FirstChildOf(parent.clone().into()))
.or_insert_with(Vec::new)
.extend(what)
}
pub fn replace<T: Clone + Into<SyntaxElement>>(&mut self, what: &T, with: &T) {
let what = what.clone().into();
let replacement = Replacement::Single(with.clone().into());
Expand All @@ -330,7 +421,7 @@ impl<'a> SyntaxRewriter<'a> {
}

pub fn rewrite(&self, node: &SyntaxNode) -> SyntaxNode {
if self.f.is_none() && self.replacements.is_empty() {
if self.f.is_none() && self.replacements.is_empty() && self.insertions.is_empty() {
return node.clone();
}
self.rewrite_children(node)
Expand All @@ -346,14 +437,22 @@ impl<'a> SyntaxRewriter<'a> {
///
/// Returns `None` when there are no replacements.
pub fn rewrite_root(&self) -> Option<SyntaxNode> {
fn element_to_node_or_parent(element: &SyntaxElement) -> SyntaxNode {
match element {
SyntaxElement::Node(it) => it.clone(),
SyntaxElement::Token(it) => it.parent(),
}
}

assert!(self.f.is_none());
self.replacements
.keys()
.map(|element| match element {
SyntaxElement::Node(it) => it.clone(),
SyntaxElement::Token(it) => it.parent(),
})
// If we only have one replacement, we must return its parent node, since `rewrite` does
.map(element_to_node_or_parent)
.chain(self.insertions.keys().map(|pos| match pos {
InsertPos::FirstChildOf(it) => it.clone(),
InsertPos::After(it) => element_to_node_or_parent(it),
}))
// If we only have one replacement/insertion, we must return its parent node, since `rewrite` does
// not replace the node passed to it.
.map(|it| it.parent().unwrap_or(it))
.fold1(|a, b| least_common_ancestor(&a, &b).unwrap())
Expand All @@ -367,9 +466,16 @@ impl<'a> SyntaxRewriter<'a> {
self.replacements.get(element).cloned()
}

fn insertions(&self, pos: &InsertPos) -> Option<impl Iterator<Item = SyntaxElement> + '_> {
self.insertions.get(pos).map(|insertions| insertions.iter().cloned())
}

fn rewrite_children(&self, node: &SyntaxNode) -> SyntaxNode {
// FIXME: this could be made much faster.
let mut new_children = Vec::new();
if let Some(elements) = self.insertions(&InsertPos::FirstChildOf(node.clone())) {
new_children.extend(elements.map(element_to_green));
}
for child in node.children_with_tokens() {
self.rewrite_self(&mut new_children, &child);
}
Expand All @@ -383,34 +489,45 @@ impl<'a> SyntaxRewriter<'a> {
) {
if let Some(replacement) = self.replacement(&element) {
match replacement {
Replacement::Single(NodeOrToken::Node(it)) => {
acc.push(NodeOrToken::Node(it.green().clone()))
}
Replacement::Single(NodeOrToken::Token(it)) => {
acc.push(NodeOrToken::Token(it.green().clone()))
}
Replacement::Single(element) => acc.push(element_to_green(element)),
Replacement::Many(replacements) => {
acc.extend(replacements.iter().map(|it| match it {
NodeOrToken::Node(it) => NodeOrToken::Node(it.green().clone()),
NodeOrToken::Token(it) => NodeOrToken::Token(it.green().clone()),
}))
acc.extend(replacements.into_iter().map(element_to_green))
}
Replacement::Delete => (),
};
return;
} else {
match element {
NodeOrToken::Token(it) => acc.push(NodeOrToken::Token(it.green().clone())),
NodeOrToken::Node(it) => {
acc.push(NodeOrToken::Node(self.rewrite_children(it).green().clone()));
}
}
}
if let Some(elements) = self.insertions(&InsertPos::After(element.clone())) {
acc.extend(elements.map(element_to_green));
}
let res = match element {
NodeOrToken::Token(it) => NodeOrToken::Token(it.green().clone()),
NodeOrToken::Node(it) => NodeOrToken::Node(self.rewrite_children(it).green().clone()),
};
acc.push(res)
}
}

fn element_to_green(element: SyntaxElement) -> NodeOrToken<rowan::GreenNode, rowan::GreenToken> {
match element {
NodeOrToken::Node(it) => NodeOrToken::Node(it.green().clone()),
NodeOrToken::Token(it) => NodeOrToken::Token(it.green().clone()),
}
}

impl ops::AddAssign for SyntaxRewriter<'_> {
fn add_assign(&mut self, rhs: SyntaxRewriter) {
assert!(rhs.f.is_none());
self.replacements.extend(rhs.replacements)
self.replacements.extend(rhs.replacements);
for (pos, insertions) in rhs.insertions.into_iter() {
match self.insertions.entry(pos) {
indexmap::map::Entry::Occupied(mut occupied) => {
occupied.get_mut().extend(insertions)
}
indexmap::map::Entry::Vacant(vacant) => drop(vacant.insert(insertions)),
}
}
}
}

Expand Down