Add a new request to get inlay hints (#764)

Co-authored-by: ryuukk <ryuukk.dev@gmail.com>

README.md

@@ -314,6 +314,19 @@ Otherwise the client outputs _00000_ so that the length of the answer is guarant
     45
     133
 
+## Inlay Hints
+
+Build a list of extra annoations for your IDE to display.
+You must submit the content of the current file displayed in your editor.
+
+    dcd-client --inlayHints
+
+This is a W.I.P., currently it only provide annoatations about aliases for your variables,
+more is planned.
+
+#### Example output
+
+    l   ->MyAlias->MyType   42
 
 # Server
 

common/src/dcd/common/messages.d

@@ -78,10 +78,12 @@ enum RequestKind : ushort
 	localUse =     	 0b00000010_00000000,
 	/// Remove import directory from server
 	removeImport =   0b00000100_00000000,
+    /// Get inlay hints
+	inlayHints =     0b00001000_00000000,
 
 	/// These request kinds require source code and won't be executed if there
 	/// is no source sent
-	requiresSourceCode = autocomplete | doc | symbolLocation | search | localUse,
+	requiresSourceCode = autocomplete | doc | symbolLocation | search | localUse | inlayHints,
 	// dfmt on
 }
 

src/dcd/client/client.d

@@ -62,6 +62,7 @@ int runClient(string[] args)
 	bool clearCache;
 	bool symbolLocation;
 	bool doc;
+	bool inlayHints;
 	bool query;
 	bool printVersion;
 	bool listImports;
@@ -86,6 +87,7 @@ int runClient(string[] args)
 			"R", &removedImportPaths, "port|p", &port, "help|h", &help,
 			"shutdown", &shutdown, "clearCache", &clearCache,
 			"symbolLocation|l", &symbolLocation, "doc|d", &doc,
+			"inlayHints", &inlayHints,
 			"query|status|q", &query, "search|s", &search,
 			"version", &printVersion, "listImports", &listImports,
 			"tcp", &useTCP, "socketFile", &socketFile,
@@ -181,7 +183,7 @@ int runClient(string[] args)
 		printImportList(response);
 		return 0;
 	}
-	else if (search == null && cursorPos == size_t.max)
+	else if (search == null && !inlayHints && cursorPos == size_t.max)
 	{
 		// cursor position is a required argument
 		printHelp(args[0]);
@@ -234,6 +236,8 @@ int runClient(string[] args)
 		request.kind |= RequestKind.search;
 	else if(localUse)
 		request.kind |= RequestKind.localUse;
+    else if (inlayHints)
+		request.kind |= RequestKind.inlayHints;
 	else
 		request.kind |= RequestKind.autocomplete;
 
@@ -255,6 +259,8 @@ int runClient(string[] args)
 		printSearchResponse(response);
 	else if (localUse)
 		printLocalUse(response);
+	else if (inlayHints)
+		printInlayHintsResponse(response);
 	else
 		printCompletionResponse(response, fullOutput);
 
@@ -295,6 +301,10 @@ Options:
         Gets documentation comments associated with the symbol at the cursor
         location.
 
+    --inlayHints
+        For all supported variable usages, show value types. Currently shows
+        alias definitions.
+
     --search | -s symbolName
         Searches for symbolName in both stdin / the given file name as well as
         others files cached by the server.
@@ -384,6 +394,21 @@ void printLocationResponse(ref const AutocompleteResponse response)
 		writeln(makeTabSeparated(response.symbolFilePath, response.symbolLocation.to!string));
 }
 
+void printInlayHintsResponse(ref const AutocompleteResponse response)
+{
+	auto app = appender!(string[])();
+	foreach (ref completion; response.completions)
+	{
+		app.put(makeTabSeparated(
+			completion.kind == char.init ? "" : "" ~ completion.kind,
+			completion.identifier,
+			completion.symbolLocation.to!string
+		));
+	}
+	foreach (line; app.data)
+		writeln(line);
+}
+
 void printCompletionResponse(ref const AutocompleteResponse response, bool extended)
 {
 	if (response.completions.length > 0)

src/dcd/server/autocomplete/inlayhints.d

@@ -0,0 +1,108 @@
+/**
+ * This file is part of DCD, a development tool for the D programming language.
+ * Copyright (C) 2014 Brian Schott
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+module dcd.server.autocomplete.inlayhints;
+
+import std.stdio;
+import std.algorithm;
+import std.array;
+import std.experimental.allocator;
+import std.experimental.logger;
+import std.typecons;
+
+import dcd.server.autocomplete.util;
+
+import dparse.lexer;
+import dparse.rollback_allocator;
+
+import dsymbol.modulecache;
+import dsymbol.symbol;
+import dsymbol.scope_;
+import dsymbol.conversion;
+import dsymbol.string_interning;
+
+import dcd.common.messages;
+
+import containers.hashset;
+
+public AutocompleteResponse getInlayHints(const AutocompleteRequest request,
+	ref ModuleCache moduleCache)
+{
+//	trace("Getting inlay hints comments");
+	AutocompleteResponse response;
+
+	LexerConfig config;
+	config.fileName = "";
+	auto cache = StringCache(request.sourceCode.length.optimalBucketCount);
+	auto tokenArray = getTokensForParser(cast(ubyte[]) request.sourceCode, config, &cache);
+	RollbackAllocator rba;
+	auto pair = generateAutocompleteTrees(tokenArray, &rba, -1, moduleCache);
+	scope(exit) pair.destroy();
+
+	void check(DSymbol* it, ref HashSet!size_t visited)
+	{
+		if (visited.contains(cast(size_t) it))
+			return;
+		if (it.symbolFile != "stdin") return;
+		visited.insert(cast(size_t) it);
+
+		//writeln("sym: ", it.name," ", it.location, " kind: ", it.kind," qualifier: ", it.qualifier);
+		//if (auto type = it.type)
+		//{
+		//	writeln("   ", type.name, " kind: ", type.kind, " qualifier", type.qualifier);
+		//	if (auto ttype = type.type)
+		//		writeln("      ", ttype.name, " kind: ", ttype.kind, " qualifier", ttype.qualifier);
+		//}
+
+
+		// aliases
+		// 		struct Data {}
+		// 		alias Alias1 = Data;
+		// 		Alias1 var;				becomes:  Alias1 [-> Data] var;
+		if (it.kind == CompletionKind.variableName && it.type && it.type.kind == CompletionKind.aliasName)
+		{
+			AutocompleteResponse.Completion c;
+			c.symbolLocation = it.location - 1;
+			c.kind = CompletionKind.aliasName;
+
+			DSymbol* type = it.type;
+
+			while (type)
+			{
+				if (type.kind == CompletionKind.aliasName && type.type)
+					c.identifier ~= "->" ~ type.type.name;
+				if (type.type && type.type.kind != CompletionKind.aliasName) break;
+				type = type.type;
+			}
+
+			response.completions ~= c;
+		}
+
+		foreach(part; it.opSlice())
+			check(part, visited);
+	}
+
+	HashSet!size_t visited;
+	foreach (symbol; pair.scope_.symbols)
+	{
+		check(symbol, visited);
+		foreach(part; symbol.opSlice())
+			check(part, visited);
+	}
+	return response;
+}

src/dcd/server/autocomplete/package.d

@@ -24,3 +24,4 @@ import dcd.server.autocomplete.complete;
 import dcd.server.autocomplete.doc;
 import dcd.server.autocomplete.localuse;
 import dcd.server.autocomplete.symbols;
+import dcd.server.autocomplete.inlayhints;

src/dcd/server/main.d

@@ -347,6 +347,11 @@ int runServer(string[] args)
 				s.trySendResponse(symbolSearch(request, cache), "Could not perform symbol search");
 			else if (request.kind & RequestKind.localUse)
 				s.trySendResponse(findLocalUse(request, cache), "Couldnot find local usage");
+			else if (request.kind & RequestKind.inlayHints)
+			{
+				info("Getting inlay hints");
+				s.trySendResponse(getInlayHints(request, cache), "Could not get inlay hints");
+			}
 			else if (needResponse)
 				s.trySendResponse(AutocompleteResponse.ack, "Could not send ack");
 		}

tests/tc_inlay_hints/expected.txt

@@ -0,0 +1 @@
+l	->Point	208

tests/tc_inlay_hints/file.d

@@ -0,0 +1,17 @@
+// when extending the inlayHints capabilities, don't forget to update the --help
+// text inside client.d
+
+import point;
+import point : P = Point;
+
+void foo(int x, int y) {}
+void foo(Point point) {}
+void bar(P point, int z = 1) {}
+
+void main()
+{
+	P p;
+	foo(1, 2);
+	foo(p);
+	bar(p, 3);
+}

tests/tc_inlay_hints/run.sh

@@ -0,0 +1,5 @@
+set -e
+set -u
+
+../../bin/dcd-client $1 --inlayHints file.d > actual.txt
+diff actual.txt expected.txt --strip-trailing-cr