Added ConvertToConcatenatedStringIntention

idea/src/META-INF/plugin.xml

@@ -719,6 +719,11 @@
       <category>Kotlin</category>
     </intentionAction>
 
+    <intentionAction>
+      <className>org.jetbrains.jet.plugin.intentions.ConvertToConcatenatedStringIntention</className>
+      <category>Kotlin</category>
+    </intentionAction>
+
     <localInspection implementationClass="org.jetbrains.jet.plugin.inspections.ExplicitGetInspection"
         displayName="Explicit 'get'"
         groupName="Kotlin"

idea/src/org/jetbrains/jet/plugin/JetBundle.properties

@@ -324,6 +324,8 @@ convert.to.for.each.function.call.intention=Replace with a forEach function call
 convert.to.for.each.function.call.intention.family=Replace with a forEach Function Call
 convert.to.string.template=Convert concatenation to template
 convert.to.string.template.family=Convert Concatenation to Template
+convert.to.concatenated.string.intention=Convert template to concatenated string
+convert.to.concatenated.string.intention.family=Convert Template to Concatenated String
 
 property.is.implemented.too.many=Has implementations
 property.is.overridden.too.many=Is overridden in subclasses

idea/src/org/jetbrains/jet/plugin/intentions/ConvertToConcatenatedStringIntention.kt

@@ -0,0 +1,70 @@
+package org.jetbrains.jet.plugin.intentions
+
+import org.jetbrains.jet.lang.psi.JetStringTemplateExpression
+import com.intellij.openapi.editor.Editor
+import org.jetbrains.jet.lang.psi.JetPsiFactory
+import org.jetbrains.jet.lang.psi.JetStringTemplateEntry
+import org.jetbrains.jet.lang.psi.JetBinaryExpression
+import org.jetbrains.jet.lang.psi.JetStringTemplateEntryWithExpression
+import org.jetbrains.jet.lang.psi.JetExpression
+import org.jetbrains.jet.plugin.project.AnalyzerFacadeWithCache
+import org.jetbrains.jet.lang.resolve.BindingContextUtils
+import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns
+import org.jetbrains.jet.lang.psi.JetIfExpression
+import org.jetbrains.jet.lang.psi.JetBlockExpression
+
+public class ConvertToConcatenatedStringIntention : JetSelfTargetingIntention<JetStringTemplateExpression>("convert.to.concatenated.string.intention", javaClass()) {
+    override fun isApplicableTo(element: JetStringTemplateExpression): Boolean {
+        return element.getEntries().any { it is JetStringTemplateEntryWithExpression }
+    }
+
+    override fun applyTo(element: JetStringTemplateExpression, editor: Editor) {
+        val tripleQuoted = isTripleQuoted(element.getText()!!)
+        val quote = if (tripleQuoted) "\"\"\"" else "\""
+        val entries = element.getEntries()
+
+        val result = entries.stream()
+                .withIndices()
+                .map { indexToEntry ->
+                    val (index, entry) = indexToEntry
+                    entry.toSeparateString(quote, convertExplicitly = index == 0, isFinalEntry = index == entries.size - 1)
+                }
+                .makeString(separator = "+")
+                .replaceAll("""$quote\+$quote""", "")
+
+        val replacement = JetPsiFactory.createExpression(element.getProject(), result)
+
+        element.replace(replacement)
+    }
+
+    private fun isTripleQuoted(str: String) = str.startsWith("\"\"\"") && str.endsWith("\"\"\"")
+
+    private fun JetStringTemplateEntry.toSeparateString(quote: String, convertExplicitly: Boolean, isFinalEntry: Boolean): String {
+        if (this !is JetStringTemplateEntryWithExpression) return getText()!!.quote(quote)
+
+        val expression = getExpression()!!
+
+        val expressionText = if (needsParenthesis(expression, isFinalEntry)) "(${expression.getText()})" else expression.getText()!!
+        return if (convertExplicitly && !expression.isStringExpression()) {
+            expressionText + ".toString()"
+        }
+        else {
+            expressionText
+        }
+    }
+
+    private fun needsParenthesis(expression: JetExpression, isFinalEntry: Boolean) = when (expression) {
+        is JetBinaryExpression -> true
+        is JetIfExpression -> expression.getElse() !is JetBlockExpression && !isFinalEntry
+        else -> false
+    }
+
+    private fun String.quote(quote: String) = quote + this + quote
+
+    private fun JetExpression.isStringExpression(): Boolean {
+        val context = AnalyzerFacadeWithCache.getContextForElement(this)
+        val elementType = BindingContextUtils.getRecordedTypeInfo(this, context)?.getType()
+
+        return KotlinBuiltIns.getInstance().isString(elementType)
+    }
+}