snakeCase() macro for live templates (PY-9989)

platform/lang-impl/src/com/intellij/codeInsight/template/macro/CapitalizeAndUnderscoreMacro.java

@@ -32,23 +32,31 @@ public class CapitalizeAndUnderscoreMacro extends MacroBase {
     super("capitalizeAndUnderscore", CodeInsightBundle.message("macro.capitalizeAndUnderscore.string"));
   }
 
+  protected CapitalizeAndUnderscoreMacro(String name, String description) {
+    super(name, description);
+  }
+
   @Override
   protected Result calculateResult(@NotNull Expression[] params, ExpressionContext context, boolean quick) {
     String text = getTextResult(params, context, true);
     if (text != null && text.length() > 0) {
       final String[] words = NameUtil.nameToWords(text);
       boolean insertUnderscore = false;
-      final StringBuffer buf = new StringBuffer();
+      final StringBuilder buf = new StringBuilder();
       for (String word : words) {
         if (insertUnderscore) {
           buf.append("_");
         } else {
           insertUnderscore = true;
         }
-        buf.append(StringUtil.toUpperCase(word));
+        buf.append(convertCase(word));
       }
       return new TextResult(buf.toString());
     }
     return null;
   }
+
+  protected String convertCase(String word) {
+    return StringUtil.toUpperCase(word);
+  }
 }

platform/lang-impl/src/com/intellij/codeInsight/template/macro/SnakeCaseMacro.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2000-2013 JetBrains s.r.o.
+ *
+ * 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 com.intellij.codeInsight.template.macro;
+
+/**
+ * @author yole
+ */
+public class SnakeCaseMacro extends CapitalizeAndUnderscoreMacro {
+  public SnakeCaseMacro() {
+    super("snakeCase", "snakeCase(String)");
+  }
+
+  @Override
+  protected String convertCase(String word) {
+    return word.toLowerCase();
+  }
+}

platform/platform-resources/src/META-INF/LangExtensions.xml

@@ -432,6 +432,7 @@
     <liveTemplateMacro implementation="com.intellij.codeInsight.template.macro.FileNameWithoutExtensionMacro"/>
     <liveTemplateMacro implementation="com.intellij.codeInsight.template.macro.ReplaceUnderscoresToCamelCaseMacro"/>
     <liveTemplateMacro implementation="com.intellij.codeInsight.template.macro.CapitalizeAndUnderscoreMacro"/>
+    <liveTemplateMacro implementation="com.intellij.codeInsight.template.macro.SnakeCaseMacro"/>
 
     <liveTemplateMacro implementation="com.intellij.codeInsight.template.macro.CompleteMacro"/>
     <liveTemplateMacro implementation="com.intellij.codeInsight.template.macro.CompleteSmartMacro"/>