Add hover handler for command symbols

CHANGELOG.md

@@ -5,6 +5,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added
+
+- Allow hovering over symbol-like commands (e. g. `\pi`) to show a unicode preview
+  or a preview image if the client supports it ([#1261](https://github.com/latex-lsp/texlab/issues/1261))
+
 ## [5.21.0] - 2024-10-26
 
 ### Added

crates/completion-data/Cargo.toml

@@ -7,6 +7,7 @@ edition.workspace = true
 rust-version.workspace = true
 
 [dependencies]
+base-db = { path = "../base-db" }
 flate2 = "1.0.34"
 itertools.workspace = true
 once_cell.workspace = true

crates/completion-data/src/lib.rs

@@ -133,3 +133,24 @@ pub static DATABASE: Lazy<Database<'static>> = Lazy::new(|| {
 
     db
 });
+
+pub fn included_packages<'a>(
+    params: &'a base_db::FeatureParams<'a>,
+) -> impl Iterator<Item = &'static crate::Package<'static>> + 'a {
+    let db = &crate::DATABASE;
+    let documents = params.project.documents.iter();
+    let links = documents
+        .filter_map(|document| document.data.as_tex())
+        .flat_map(|data| data.semantics.links.iter());
+
+    links
+        .filter_map(|link| link.package_name())
+        .filter_map(|name| db.find(&name))
+        .chain(std::iter::once(db.kernel()))
+        .flat_map(|pkg| {
+            pkg.references
+                .iter()
+                .filter_map(|name| db.find(name))
+                .chain(std::iter::once(pkg))
+        })
+}

crates/completion/src/providers/argument.rs

@@ -1,9 +1,10 @@
 use base_db::semantics::Span;
+use completion_data::included_packages;
 use rowan::{ast::AstNode, TokenAtOffset};
 use syntax::latex;
 
 use crate::{
-    util::{included_packages, is_inside_latex_curly, CompletionBuilder},
+    util::{is_inside_latex_curly, CompletionBuilder},
     ArgumentData, CompletionItem, CompletionItemData, CompletionParams,
 };
 

crates/completion/src/providers/command.rs

@@ -1,9 +1,10 @@
 use base_db::{semantics::Span, DocumentData};
+use completion_data::included_packages;
 use rowan::{TextRange, TextSize};
 use syntax::{bibtex, latex};
 
 use crate::{
-    util::{included_packages, CompletionBuilder, ProviderContext},
+    util::{CompletionBuilder, ProviderContext},
     CommandData, CompletionItem, CompletionItemData, CompletionParams,
 };
 

crates/completion/src/providers/environment.rs

@@ -1,9 +1,10 @@
 use base_db::semantics::Span;
+use completion_data::included_packages;
 use rowan::ast::AstNode;
 use syntax::latex;
 
 use crate::{
-    util::{find_curly_group_word, included_packages, CompletionBuilder, ProviderContext},
+    util::{find_curly_group_word, CompletionBuilder, ProviderContext},
     CompletionItem, CompletionItemData, CompletionParams, EnvironmentData,
 };
 

crates/completion/src/util.rs

@@ -5,27 +5,6 @@ mod patterns;
 pub use builder::*;
 pub use patterns::*;
 
-pub fn included_packages<'a>(
-    params: &'a base_db::FeatureParams<'a>,
-) -> impl Iterator<Item = &completion_data::Package<'_>> + 'a {
-    let db = &completion_data::DATABASE;
-    let documents = params.project.documents.iter();
-    let links = documents
-        .filter_map(|document| document.data.as_tex())
-        .flat_map(|data| data.semantics.links.iter());
-
-    links
-        .filter_map(|link| link.package_name())
-        .filter_map(|name| db.find(&name))
-        .chain(std::iter::once(db.kernel()))
-        .flat_map(|pkg| {
-            pkg.references
-                .iter()
-                .filter_map(|name| db.find(name))
-                .chain(std::iter::once(pkg))
-        })
-}
-
 pub struct ProviderContext<'a, 'b> {
     pub builder: &'b mut CompletionBuilder<'a>,
     pub params: &'a crate::CompletionParams<'a>,

crates/hover/src/command.rs

@@ -0,0 +1,19 @@
+use syntax::latex;
+
+use crate::{Hover, HoverData, HoverParams};
+
+pub(super) fn find_hover<'a>(params: &HoverParams<'a>) -> Option<Hover<'a>> {
+    let data = params.feature.document.data.as_tex()?;
+    let name = data
+        .root_node()
+        .token_at_offset(params.offset)
+        .find(|token| token.kind() == latex::COMMAND_NAME)?;
+
+    let command = completion_data::included_packages(&params.feature)
+        .flat_map(|package| package.commands.iter())
+        .find(|command| command.name == &name.text()[1..])?;
+
+    let range = name.text_range();
+    let data = HoverData::Command(command);
+    Some(Hover { range, data })
+}

crates/hover/src/lib.rs

@@ -1,4 +1,5 @@
 mod citation;
+mod command;
 mod entry_type;
 mod field_type;
 mod label;
@@ -19,18 +20,19 @@ pub struct HoverParams<'a> {
 }
 
 #[derive(Debug, Clone)]
-pub struct Hover<'db> {
+pub struct Hover<'a> {
     pub range: TextRange,
-    pub data: HoverData<'db>,
+    pub data: HoverData<'a>,
 }
 
 #[derive(Debug, Clone)]
-pub enum HoverData<'db> {
+pub enum HoverData<'a> {
     Citation(String),
-    Package(&'db str),
-    EntryType(BibtexEntryType<'db>),
-    FieldType(BibtexFieldType<'db>),
-    Label(RenderedLabel<'db>),
+    Package(&'a str),
+    Command(&'a completion_data::Command<'static>),
+    EntryType(BibtexEntryType<'a>),
+    FieldType(BibtexFieldType<'a>),
+    Label(RenderedLabel<'a>),
     StringRef(String),
 }
 
@@ -41,6 +43,7 @@ pub fn find<'a>(params: &HoverParams<'a>) -> Option<Hover<'a>> {
         .or_else(|| field_type::find_hover(params))
         .or_else(|| label::find_hover(params))
         .or_else(|| string_ref::find_hover(params))
+        .or_else(|| command::find_hover(params))
 }
 
 #[cfg(test)]

crates/hover/src/tests.rs

@@ -352,3 +352,69 @@ fn test_latex_label_ntheorem() {
         "#]],
     );
 }
+
+#[test]
+fn test_symbol_command_kernel() {
+    check(
+        r#"
+%! main.tex
+\pi
+  |
+^^^"#,
+        expect![[r#"
+            Some(
+                Command(
+                    Command {
+                        name: "pi",
+                        image: Some(
+                            "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",
+                        ),
+                        glyph: Some(
+                            "π",
+                        ),
+                        parameters: [],
+                    },
+                ),
+            )
+        "#]],
+    );
+}
+
+#[test]
+fn test_symbol_command_package() {
+    check(
+        r#"
+%! main.tex
+\usepackage{amsmath}
+\varDelta
+   |
+^^^^^^^^^"#,
+        expect![[r#"
+            Some(
+                Command(
+                    Command {
+                        name: "varDelta",
+                        image: Some(
+                            "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",
+                        ),
+                        glyph: None,
+                        parameters: [],
+                    },
+                ),
+            )
+        "#]],
+    );
+}
+
+#[test]
+fn test_symbol_command_package_not_included() {
+    check(
+        r#"
+%! main.tex
+\varDelta
+   |"#,
+        expect![[r#"
+            None
+        "#]],
+    );
+}

crates/texlab/src/features/hover.rs

@@ -1,9 +1,13 @@
 use base_db::Workspace;
 
-use crate::util::{from_proto, to_proto};
+use crate::util::{from_proto, to_proto, ClientFlags};
 
-pub fn find(workspace: &Workspace, params: lsp_types::HoverParams) -> Option<lsp_types::Hover> {
+pub fn find(
+    workspace: &Workspace,
+    params: lsp_types::HoverParams,
+    client_flags: &ClientFlags,
+) -> Option<lsp_types::Hover> {
     let params = from_proto::hover_params(workspace, params)?;
     let hover = ::hover::find(&params)?;
-    to_proto::hover(hover, &params.feature.document.line_index)
+    to_proto::hover(hover, &params.feature.document.line_index, client_flags)
 }

crates/texlab/src/server.rs

@@ -547,8 +547,9 @@ impl Server {
     fn hover(&mut self, id: RequestId, mut params: HoverParams) -> Result<()> {
         normalize_uri(&mut params.text_document_position_params.text_document.uri);
         let uri_and_pos = &params.text_document_position_params;
+        let client_flags = Arc::clone(&self.client_flags);
         self.update_cursor(&uri_and_pos.text_document.uri, uri_and_pos.position);
-        self.run_query(id, move |db| hover::find(db, params));
+        self.run_query(id, move |db| hover::find(db, params, &client_flags));
         Ok(())
     }
 

crates/texlab/src/util/client_flags.rs

@@ -9,6 +9,10 @@ pub struct ClientFlags {
     /// This is used to include images via base64 encoding.
     pub completion_markdown: bool,
 
+    /// If `true`, the server can include markdown in hover results.
+    /// This is used to include images via base64 encoding.
+    pub hover_markdown: bool,
+
     /// If `true`, the server can include snippets like `\begin{...}` in completion items.
     pub completion_snippets: bool,
 

crates/texlab/src/util/from_proto.rs

@@ -38,6 +38,16 @@ pub fn client_flags(
             formats.contains(&lsp_types::MarkupKind::Markdown)
         });
 
+    let hover_markdown = capabilities
+        .text_document
+        .as_ref()
+        .and_then(|cap| cap.hover.as_ref())
+        .and_then(|cap| cap.content_format.as_ref())
+        .map_or(false, |cap| {
+            // Use the preferred format of the editor instead of just markdown (if available).
+            cap.first() == Some(&lsp_types::MarkupKind::Markdown)
+        });
+
     let completion_snippets = capabilities
         .text_document
         .as_ref()
@@ -92,6 +102,7 @@ pub fn client_flags(
     ClientFlags {
         hierarchical_document_symbols,
         completion_markdown,
+        hover_markdown,
         completion_snippets,
         completion_kinds,
         completion_always_incomplete,

crates/texlab/src/util/to_proto.rs

@@ -446,7 +446,33 @@ pub fn document_highlight(
     Some(lsp_types::DocumentHighlight { range, kind })
 }
 
-pub fn hover(hover: Hover, line_index: &LineIndex) -> Option<lsp_types::Hover> {
+pub fn hover(
+    hover: Hover,
+    line_index: &LineIndex,
+    client_flags: &ClientFlags,
+) -> Option<lsp_types::Hover> {
+    fn inline_image(
+        command: &completion_data::Command,
+
+        client_flags: &ClientFlags,
+    ) -> Option<lsp_types::MarkupContent> {
+        let name = &command.name;
+        command
+            .image
+            .map(|base64| format!("![{name}](data:image/png;base64,{base64}|width=48,height=48)"))
+            .filter(|_| client_flags.hover_markdown)
+            .map(|value| lsp_types::MarkupContent {
+                kind: lsp_types::MarkupKind::Markdown,
+                value,
+            })
+            .or_else(|| {
+                Some(lsp_types::MarkupContent {
+                    kind: lsp_types::MarkupKind::PlainText,
+                    value: command.glyph.as_deref()?.into(),
+                })
+            })
+    }
+
     let contents = match hover.data {
         HoverData::Citation(text) => lsp_types::MarkupContent {
             kind: lsp_types::MarkupKind::Markdown,
@@ -456,6 +482,7 @@ pub fn hover(hover: Hover, line_index: &LineIndex) -> Option<lsp_types::Hover> {
             kind: lsp_types::MarkupKind::PlainText,
             value: description.into(),
         },
+        HoverData::Command(command) => inline_image(command, client_flags)?,
         HoverData::EntryType(type_) => lsp_types::MarkupContent {
             kind: lsp_types::MarkupKind::Markdown,
             value: type_.documentation?.into(),