Code action support (vala-lang#237)

Implement `textDocument/codeAction` with an action to convert integer literals to hexdecimal and octal.

Co-authored-by: Princeton Ferro <[email protected]>

plugins/gnome-builder/vala_langserv.plugin.in

@@ -6,6 +6,7 @@ Copyright=Copyright © 2020
 
 Loader=python3
 Module=vala_langserv
+X-Code-Action-Languages=vala
 X-Completion-Provider-Languages=vala
 X-Diagnostic-Provider-Languages=vala
 X-Formatter-Languages=vala

plugins/gnome-builder/vala_langserv.py

@@ -199,6 +199,10 @@ def do_prepare(self):
         self.props.priority = 100
         VlsService.bind_client(self)
 
+class VlsCodeActionProvider(Ide.LspCodeActionProvider):
+    def do_load(self):
+        VlsService.bind_client(self)
+
 if hasattr(Ide, 'LspSearchProvider'):       # for earlier versions of Builder
     class VlsSearchProvider(Ide.LspSearchProvider):
         def do_load(self, context):

src/codeaction/baseconverteraction.vala

@@ -0,0 +1,67 @@
+/* baseconverteraction.vala
+ *
+ * Copyright 2022 JCWasmx86 <[email protected]>
+ *
+ * This file is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This file 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ */
+
+using Lsp;
+using Gee;
+
+/**
+ * The base converter code action allows to convert a constant to a different base.
+ * For example:
+ * ```vala
+ * int x = 10;   // actions: convert to 0xA or 012
+ * ```
+ */
+class Vls.BaseConverterAction : CodeAction {
+    public BaseConverterAction (Vala.IntegerLiteral lit, VersionedTextDocumentIdentifier document) {
+        string val = lit.value;
+        // bool signed = lit.type_suffix[0] == 'u' || lit.type_suffix[0] == 'U';
+        bool negative = false;
+        if (val[0] == '-') {
+            negative = true;
+            val = val[1:];
+        }
+        var workspace_edit = new WorkspaceEdit ();
+        var document_edit = new TextDocumentEdit () {
+            textDocument = document
+        };
+        var text_edit = new TextEdit () {
+            range = new Range.from_sourceref (lit.source_reference)
+        };
+        if (val.has_prefix ("0x")) {
+            // base 16  -> base 8
+            val = val[2:];
+            text_edit.newText = "%s%#llo".printf (negative ? "-" : "", ulong.parse (val, 16));
+            this.title = "Convert hexadecimal value to octal";
+        } else if (val[0] == '0') {
+            // base 8   -> base 10
+            val = val[1:];
+            text_edit.newText = "%s%#lld".printf (negative ? "-" : "", ulong.parse (val, 8));
+            this.title = "Convert octal value to decimal";
+        } else {
+            // base 10  -> base 16
+            text_edit.newText = "%s%#llx".printf (negative ? "-" : "", ulong.parse (val));
+            this.title = "Convert decimal value to hexadecimal";
+        }
+        document_edit.edits.add (text_edit);
+        workspace_edit.documentChanges = new ArrayList<TextDocumentEdit> ();
+        workspace_edit.documentChanges.add (document_edit);
+        this.edit = workspace_edit;
+    }
+}