Fix server capabilities, add semantic tokens config option, fix semantic tokens basic implementation

README.md

@@ -52,11 +52,12 @@ The following options are currently available.
 
 | Option | Type | Default value | What it Does |
 | --- | --- | --- | --- |
-| `enable_snippets` | `bool` | `false` | Enables snippet completion, set to false for compatibility with language clients that do not support snippets (such as ale). |
+| `enable_snippets` | `bool` | `false` | Enables snippet completions when the client also supports them. |
 | `zig_lib_path` | `?[]const u8` | `null` | zig library path, e.g. `/path/to/zig/lib/zig`, used to analyze std library imports. |
 | `zig_exe_path` | `?[]const u8` | `null` | zig executable path, e.g. `/path/to/zig/zig`, used to run the custom build runner. If `null`, zig is looked up in `PATH`. Will be used to infer the zig standard library path if none is provided. |
 | `warn_style` | `bool` | `false` | Enables warnings for style *guideline* mismatches |
 | `build_runner_path` | `?[]const u8` | `null` | Path to the build_runner.zig file provided by zls. This option must be present in one of the global configuration files to have any effect. `null` is equivalent to `${executable_directory}/build_runner.zig` |
+| `enable_semantic_tokens` | `bool` | false | Enables semantic token support when the client also supports it. |
 
 ## Usage
 

src/config.zig

@@ -17,3 +17,6 @@ warn_style: bool = false,
 /// Path to the build_runner.zig file. This option must be present in one of
 /// the global configuration directories to have any effect.
 build_runner_path: ?[]const u8 = null,
+
+/// Semantic token support
+enable_semantic_tokens: bool = false,

src/main.zig

@@ -28,7 +28,7 @@ const ClientCapabilities = struct {
 var client_capabilities = ClientCapabilities{};
 
 const initialize_response =
-    \\,"result":{"capabilities":{"signatureHelpProvider":{"triggerCharacters":["(",","]},"textDocumentSync":1,"completionProvider":{"resolveProvider":false,"triggerCharacters":[".",":","@"]},"documentHighlightProvider":false,"hoverProvider":true,"codeActionProvider":false,"declarationProvider":true,"definitionProvider":true,"typeDefinitionProvider":true,"implementationProvider":false,"referencesProvider":false,"documentSymbolProvider":true,"colorProvider":false,"documentFormattingProvider":false,"documentRangeFormattingProvider":false,"foldingRangeProvider":false,"selectionRangeProvider":false,"workspaceSymbolProvider":false,"rangeProvider":false,"documentProvider":true},"workspace":{"workspaceFolders":{"supported":true,"changeNotifications":true}},"semanticTokensProvider":{"documentProvider":true, "legend":{"tokenTypes":["type","struct","enum","union","parameter","variable","tagField","field","function","keyword","modifier","comment","string","number","operator","builtin"],"tokenModifiers":["definition","async","documentation"]}}}}
+    \\,"result": {"capabilities": {"signatureHelpProvider": {"triggerCharacters": ["(",","]},"textDocumentSync": 1,"completionProvider": {"resolveProvider": false,"triggerCharacters": [".",":","@"]},"documentHighlightProvider": false,"hoverProvider": true,"codeActionProvider": false,"declarationProvider": true,"definitionProvider": true,"typeDefinitionProvider": true,"implementationProvider": false,"referencesProvider": false,"documentSymbolProvider": true,"colorProvider": false,"documentFormattingProvider": false,"documentRangeFormattingProvider": false,"foldingRangeProvider": false,"selectionRangeProvider": false,"workspaceSymbolProvider": false,"rangeProvider": false,"documentProvider": true,"workspace": {"workspaceFolders": {"supported": true,"changeNotifications": true}},"semanticTokensProvider": {"documentProvider": true,"legend": {"tokenTypes": ["type","struct","enum","union","parameter","variable","tagField","field","function","keyword","modifier","comment","string","number","operator","builtin"],"tokenModifiers": ["definition","async","documentation"]}}}}}
 ;
 
 const not_implemented_response =
@@ -50,6 +50,9 @@ const edit_not_applied_response =
 const no_completions_response =
     \\,"result":{"isIncomplete":false,"items":[]}}
 ;
+const no_semantic_tokens_response =
+    \\,"result":{"data":[]}}
+;
 
 /// Sends a request or response
 fn send(reqOrRes: var) !void {
@@ -997,20 +1000,23 @@ fn processJsonRpc(parser: *std.json.Parser, json: []const u8, config: Config) !v
         const document = params.getValue("textDocument").?.Object;
         const uri = document.getValue("uri").?.String;
 
-        const handle = document_store.getHandle(uri) orelse {
-            std.debug.warn("Trying to complete in non existent document {}", .{uri});
-            return try respondGeneric(id, no_completions_response);
-        };
+        const this_config = configFromUriOr(uri, config);
+        if (this_config.enable_semantic_tokens) {
+            const handle = document_store.getHandle(uri) orelse {
+                std.debug.warn("Trying to complete in non existent document {}", .{uri});
+                return try respondGeneric(id, no_semantic_tokens_response);
+            };
 
-        // TODO Actually test this in some editor, VSCode won't send me requests -_-'.
-        const semantic_tokens = @import("semantic_tokens.zig");
-        const token_array = try semantic_tokens.writeAllSemanticTokens(allocator, handle.*);
-        defer allocator.free(token_array);
+            const semantic_tokens = @import("semantic_tokens.zig");
+            const token_array = try semantic_tokens.writeAllSemanticTokens(allocator, handle.*);
+            defer allocator.free(token_array);
 
-        return try send(types.Response{
-            .id = id,
-            .result = .{ .SemanticTokens = .{ .data = token_array } },
-        });
+            return try send(types.Response{
+                .id = id,
+                .result = .{ .SemanticTokens = .{ .data = token_array } },
+            });
+        } else
+            return try respondGeneric(id, no_semantic_tokens_response);
     }
     // Autocomplete / Signatures
     else if (std.mem.eql(u8, method, "textDocument/completion")) {

src/semantic_tokens.zig

@@ -54,15 +54,15 @@ const Builder = struct {
 
     fn add(self: *Builder, token: ast.TokenIndex, token_type: TokenType, token_modifiers: TokenModifiers) !void {
         const start_idx = if (self.current_token) |current_token|
-            self.tree.token_locs[current_token].start + 1
+            self.tree.token_locs[current_token].start
         else
             0;
 
         const token_loc = self.tree.token_locs[token];
         const delta_loc = self.tree.tokenLocationLoc(start_idx, token_loc);
         try self.arr.appendSlice(&[_]u32{
-            @truncate(u32, if (self.current_token == null) delta_loc.line + 1 else delta_loc.line),
-            @truncate(u32, delta_loc.column + 1),
+            @truncate(u32, delta_loc.line),
+            @truncate(u32, delta_loc.column),
             @truncate(u32, token_loc.end - token_loc.start),
             @enumToInt(token_type),
             token_modifiers.toInt(),

src/types.zig

@@ -59,7 +59,7 @@ pub const ResponseParams = union(enum) {
     Location: Location,
     Hover: Hover,
     DocumentSymbols: []DocumentSymbol,
-    SemanticTokens: struct { data: []u32 },
+    SemanticTokens: struct { data: []const u32 },
 };
 
 /// JSONRPC error