lsp: Remove explicit rowan dependency from LSP

... by implementing more helpers on `parser::SyntaxNode` and
`parser::SyntaxToken`.

internal/compiler/Cargo.toml

@@ -37,7 +37,7 @@ i-slint-common = { workspace = true, features = ["default"] }
 
 num_enum = "0.7"
 strum = { workspace = true }
-rowan = { workspace = true }
+rowan = { version = "0.15" }
 smol_str = "0.2.0"
 derive_more = { workspace = true }
 codemap-diagnostic = { version = "0.1.1", optional = true }

internal/compiler/parser.rs

@@ -762,6 +762,11 @@ impl SyntaxToken {
     pub fn parent(&self) -> SyntaxNode {
         SyntaxNode { node: self.token.parent().unwrap(), source_file: self.source_file.clone() }
     }
+    pub fn parent_ancestors(&self) -> impl Iterator<Item = SyntaxNode> + '_ {
+        self.token
+            .parent_ancestors()
+            .map(|node| SyntaxNode { node, source_file: self.source_file.clone() })
+    }
     pub fn next_token(&self) -> Option<SyntaxToken> {
         // Due to a bug (as of rowan 0.15.3), rowan::SyntaxToken::next_token doesn't work if a
         // sibling don't have tokens.
@@ -787,6 +792,10 @@ impl SyntaxToken {
             })?;
         Some(SyntaxToken { token, source_file: self.source_file.clone() })
     }
+    pub fn prev_token(&self) -> Option<SyntaxToken> {
+        let token = self.token.prev_token()?;
+        Some(SyntaxToken { token, source_file: self.source_file.clone() })
+    }
     pub fn text(&self) -> &str {
         self.token.text()
     }
@@ -847,6 +856,16 @@ impl SyntaxNode {
             .first_token()
             .map(|token| SyntaxToken { token, source_file: self.source_file.clone() })
     }
+    pub fn last_token(&self) -> Option<SyntaxToken> {
+        self.node
+            .last_token()
+            .map(|token| SyntaxToken { token, source_file: self.source_file.clone() })
+    }
+    pub fn token_at_offset(&self, offset: TextSize) -> rowan::TokenAtOffset<SyntaxToken> {
+        self.node
+            .token_at_offset(offset)
+            .map(|token| SyntaxToken { token, source_file: self.source_file.clone() })
+    }
 }
 
 #[derive(Debug, Clone, derive_more::From)]

tools/lsp/Cargo.toml

@@ -85,7 +85,6 @@ dissimilar = "1.0.7"
 euclid = { workspace = true }
 itertools = { workspace = true }
 lsp-types = { version = "0.95.0", features = ["proposed"] }
-rowan = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
 

tools/lsp/language.rs

@@ -589,7 +589,7 @@ pub fn token_at_offset(doc: &syntax_nodes::Document, offset: u32) -> Option<Synt
             _ => l,
         },
     };
-    Some(SyntaxToken { token, source_file: doc.source_file.clone() })
+    Some(token)
 }
 
 fn has_experimental_client_capability(capabilities: &ClientCapabilities, name: &str) -> bool {

tools/lsp/preview/drop_location.rs

@@ -6,7 +6,9 @@ use std::num::NonZeroUsize;
 
 use i_slint_compiler::diagnostics::{BuildDiagnostics, SourceFile};
 use i_slint_compiler::object_tree;
-use i_slint_compiler::parser::{syntax_nodes, SyntaxKind, SyntaxNode, TextRange, TextSize};
+use i_slint_compiler::parser::{
+    syntax_nodes, SyntaxKind, SyntaxNode, SyntaxToken, TextRange, TextSize,
+};
 use i_slint_core::lengths::{LogicalPoint, LogicalRect, LogicalSize};
 use slint_interpreter::ComponentInstance;
 
@@ -464,9 +466,7 @@ fn insert_position_before_first_component(
         first_exported_component
     };
 
-    fn find_pre_indent_and_replacement(
-        token: &rowan::SyntaxToken<i_slint_compiler::parser::Language>,
-    ) -> (String, u32) {
+    fn find_pre_indent_and_replacement(token: &SyntaxToken) -> (String, u32) {
         match token.kind() {
             SyntaxKind::Whitespace => {
                 if token.prev_token().is_some() {

tools/lsp/preview/properties.rs

@@ -11,7 +11,7 @@ use i_slint_compiler::diagnostics::Spanned;
 use i_slint_compiler::langtype::{ElementType, Type};
 use i_slint_compiler::object_tree::{Element, PropertyDeclaration, PropertyVisibility};
 use i_slint_compiler::parser::{
-    syntax_nodes, Language, SyntaxKind, SyntaxNode, TextRange, TextSize,
+    syntax_nodes, SyntaxKind, SyntaxNode, SyntaxToken, TextRange, TextSize,
 };
 
 use lsp_types::Url;
@@ -140,7 +140,7 @@ fn add_element_properties(
 }
 
 /// Move left from the start of a `token` to include white-space and comments that go with it.
-fn left_extend(token: rowan::SyntaxToken<Language>) -> rowan::SyntaxToken<Language> {
+fn left_extend(token: SyntaxToken) -> SyntaxToken {
     let mut current_token = token.prev_token();
     let mut start_token = token.clone();
     let mut last_comment = token;
@@ -170,7 +170,7 @@ fn left_extend(token: rowan::SyntaxToken<Language>) -> rowan::SyntaxToken<Langua
 }
 
 /// Move right from the end of the `token` to include white-space and comments that go with it.
-fn right_extend(token: rowan::SyntaxToken<Language>) -> rowan::SyntaxToken<Language> {
+fn right_extend(token: SyntaxToken) -> SyntaxToken {
     let mut current_token = token.next_token();
     let mut end_token = token.clone();
     let mut last_comment = token;