Semantic highlighting (#92)

Signed-off-by: Ben Sherman <bentshermann@gmail.com>

Author: bentsherman

README.md

@@ -10,6 +10,7 @@ The following language features are currently supported:
 - formatting
 - hover hints
 - rename
+- semantic highlighting
 - DAG preview for workflows
 
 ## Requirements

modules/compiler/src/main/java/config/parser/ConfigAstBuilder.java

@@ -92,6 +92,7 @@
 
 import static nextflow.config.parser.ConfigParser.*;
 import static nextflow.script.parser.PositionConfigureUtils.ast;
+import static nextflow.script.parser.PositionConfigureUtils.tokenPosition;
 import static org.codehaus.groovy.ast.expr.VariableExpression.THIS_EXPRESSION;
 import static org.codehaus.groovy.ast.tools.GeneralUtils.*;
 
@@ -1173,6 +1174,7 @@ private Parameter formalParameter(FormalParameterContext ctx) {
             : null;
         var result = ast( param(type, name, defaultValue), ctx );
         checkInvalidVarName(name, result);
+        result.putNodeMetaData("_START_NAME", tokenPosition(ctx.identifier()));
         return result;
     }
 

modules/compiler/src/main/java/script/parser/PositionConfigureUtils.java

@@ -135,4 +135,17 @@ public static <T extends ASTNode> T ast(T astNode, ASTNode start, ASTNode stop)
 
         return astNode;
     }
+
+    /**
+     * Get the zero-based start position (line, character) of a token.
+     *
+     * @param ctx
+     */
+    public static TokenPosition tokenPosition(ParserRuleContext ctx) {
+        var token = ctx.getStart();
+        return new TokenPosition(
+            token.getLine() - 1,
+            token.getCharPositionInLine()
+        );
+    }
 }

modules/compiler/src/main/java/script/parser/ScriptAstBuilder.java

@@ -99,6 +99,7 @@
 import org.codehaus.groovy.syntax.Types;
 
 import static nextflow.script.parser.PositionConfigureUtils.ast;
+import static nextflow.script.parser.PositionConfigureUtils.tokenPosition;
 import static nextflow.script.parser.ScriptParser.*;
 import static nextflow.script.ast.ASTHelpers.*;
 import static org.codehaus.groovy.ast.expr.VariableExpression.THIS_EXPRESSION;
@@ -339,7 +340,11 @@ private IncludeNode includeDeclaration(IncludeDeclarationContext ctx) {
             .map(it -> {
                 var name = it.name.getText();
                 var alias = it.alias != null ? it.alias.getText() : null;
-                return ast( new IncludeVariable(name, alias), it );
+                var result = new IncludeVariable(name, alias);
+                result.putNodeMetaData("_START_NAME", tokenPosition(it.name));
+                if( it.alias != null )
+                    result.putNodeMetaData("_START_ALIAS", tokenPosition(it.alias));
+                return ast( result, it );
             })
             .collect(Collectors.toList());
 
@@ -1525,6 +1530,7 @@ private Parameter formalParameter(FormalParameterContext ctx) {
             : null;
         var result = ast( param(type, name, defaultValue), ctx );
         checkInvalidVarName(name, result);
+        result.putNodeMetaData("_START_NAME", tokenPosition(ctx.identifier()));
         return result;
     }
 

modules/compiler/src/main/java/script/parser/TokenPosition.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2013-2025, Seqera Labs
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nextflow.script.parser;
+
+/**
+ *
+ * @author Ben Sherman <bentshermann@gmail.com>
+ */
+public record TokenPosition(
+    int line,           // 0-based
+    int character       // 0-based
+) {}

modules/language-server/src/main/java/nextflow/lsp/NextflowLanguageServer.java

@@ -31,6 +31,7 @@
 import nextflow.lsp.file.PathUtils;
 import nextflow.lsp.util.Logger;
 import nextflow.lsp.services.LanguageService;
+import nextflow.lsp.services.SemanticTokensVisitor;
 import nextflow.lsp.services.config.ConfigService;
 import nextflow.lsp.services.script.ScriptService;
 import nextflow.script.formatter.FormattingOptions;
@@ -76,6 +77,10 @@
 import org.eclipse.lsp4j.ProgressParams;
 import org.eclipse.lsp4j.ReferenceParams;
 import org.eclipse.lsp4j.RenameParams;
+import org.eclipse.lsp4j.SemanticTokens;
+import org.eclipse.lsp4j.SemanticTokensLegend;
+import org.eclipse.lsp4j.SemanticTokensParams;
+import org.eclipse.lsp4j.SemanticTokensWithRegistrationOptions;
 import org.eclipse.lsp4j.ServerCapabilities;
 import org.eclipse.lsp4j.SetTraceParams;
 import org.eclipse.lsp4j.SymbolInformation;
@@ -164,6 +169,14 @@ public CompletableFuture<InitializeResult> initialize(InitializeParams params) {
         serverCapabilities.setExecuteCommandProvider(executeCommandOptions);
         serverCapabilities.setHoverProvider(true);
         serverCapabilities.setReferencesProvider(true);
+        var semanticTokensOptions = new SemanticTokensWithRegistrationOptions(
+            new SemanticTokensLegend(
+                SemanticTokensVisitor.TOKEN_TYPES,
+                Collections.emptyList()
+            ),
+            true,
+            false);
+        serverCapabilities.setSemanticTokensProvider(semanticTokensOptions);
         serverCapabilities.setRenameProvider(true);
         serverCapabilities.setWorkspaceSymbolProvider(true);
 
@@ -408,6 +421,19 @@ public CompletableFuture<WorkspaceEdit> rename(RenameParams params) {
         });
     }
 
+    @Override
+    public CompletableFuture<SemanticTokens> semanticTokensFull(SemanticTokensParams params) {
+        return CompletableFutures.computeAsync((cancelChecker) -> {
+            cancelChecker.checkCanceled();
+            var uri = params.getTextDocument().getUri();
+            log.debug("textDocument/semanticTokens/full " + relativePath(uri));
+            var service = getLanguageService(uri);
+            if( service == null )
+                return null;
+            return service.semanticTokensFull(params);
+        });
+    }
+
     // --- WorkspaceService
 
     @Override

modules/language-server/src/main/java/nextflow/lsp/services/LanguageService.java

@@ -73,6 +73,8 @@
 import org.eclipse.lsp4j.PublishDiagnosticsParams;
 import org.eclipse.lsp4j.ReferenceParams;
 import org.eclipse.lsp4j.RenameParams;
+import org.eclipse.lsp4j.SemanticTokens;
+import org.eclipse.lsp4j.SemanticTokensParams;
 import org.eclipse.lsp4j.SymbolInformation;
 import org.eclipse.lsp4j.TextEdit;
 import org.eclipse.lsp4j.WorkspaceEdit;
@@ -116,6 +118,7 @@ public LanguageService() {
     protected LinkProvider getLinkProvider() { return null; }
     protected ReferenceProvider getReferenceProvider() { return null; }
     protected RenameProvider getRenameProvider() { return null; }
+    protected SemanticTokensProvider getSemanticTokensProvider() { return null; }
     protected SymbolProvider getSymbolProvider() { return null; }
 
     private volatile boolean initialized;
@@ -295,6 +298,15 @@ public WorkspaceEdit rename(RenameParams params) {
         return provider.rename(params.getTextDocument(), params.getPosition(), params.getNewName());
     }
 
+    public SemanticTokens semanticTokensFull(SemanticTokensParams params) {
+        var provider = getSemanticTokensProvider();
+        if( provider == null )
+            return null;
+
+        awaitUpdate();
+        return provider.semanticTokensFull(params.getTextDocument());
+    }
+
     public List<? extends WorkspaceSymbol> symbol(WorkspaceSymbolParams params) {
         var provider = getSymbolProvider();
         if( provider == null )

modules/language-server/src/main/java/nextflow/lsp/services/SemanticTokensProvider.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2024, Seqera Labs
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nextflow.lsp.services;
+
+import java.util.List;
+
+import org.eclipse.lsp4j.SemanticTokens;
+import org.eclipse.lsp4j.TextDocumentIdentifier;
+
+public interface SemanticTokensProvider {
+
+    SemanticTokens semanticTokensFull(TextDocumentIdentifier textDocument);
+
+}