From db488ad295f2a8f05dc53ae3d7a880c0ecfaac69 Mon Sep 17 00:00:00 2001
From: Nikolay Krasko <Nikolay.Krasko@jetbrains.com>
Date: Fri, 19 Dec 2014 16:42:48 +0300
Subject: [PATCH] Add utility function for getting text with context

---
 .../jet/lang/parsing/AbstractJetParsing.java  | 21 ++-------
 .../src/org/jetbrains/jet/utils/strings.kt    | 47 +++++++++++++++++++
 2 files changed, 51 insertions(+), 17 deletions(-)
 create mode 100644 compiler/util/src/org/jetbrains/jet/utils/strings.kt

diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/parsing/AbstractJetParsing.java b/compiler/frontend/src/org/jetbrains/jet/lang/parsing/AbstractJetParsing.java
index 9b90e5657a7..04a01503fc8 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/parsing/AbstractJetParsing.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/parsing/AbstractJetParsing.java
@@ -27,6 +27,7 @@ import org.jetbrains.annotations.TestOnly;
 import org.jetbrains.jet.lexer.JetKeywordToken;
 import org.jetbrains.jet.lexer.JetToken;
 import org.jetbrains.jet.lexer.JetTokens;
+import org.jetbrains.jet.utils.strings.StringsPackage;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -368,12 +369,8 @@ import static org.jetbrains.jet.lexer.JetTokens.*;
         currentPosition.rollbackTo();
 
         if (endOffset - beginOffset > LOOK_AHEAD_SIZE_WARN && !ApplicationManager.getApplication().isHeadlessEnvironment()) {
-            String text = new StringBuilder(myBuilder.getOriginalText())
-                    .insert(endOffset, "<~~!END!~~>")
-                    .insert(beginOffset, "<~~!BEGIN!~~>")
-                    .toString();
-
-            LOGGER.warn("Suspicious big range: \n" + text);
+            String rangeWithContext = StringsPackage.substringWithContext(myBuilder.getOriginalText(), beginOffset, endOffset, 100);
+            LOGGER.warn("Suspicious big range: \n" + rangeWithContext);
         }
 
         return pattern.result();
@@ -497,16 +494,6 @@ import static org.jetbrains.jet.lexer.JetTokens.*;
     @SuppressWarnings("UnusedDeclaration")
     @TestOnly
     public String currentContext() {
-        String marker = "~!!!~";
-        int range = 50;
-
-        CharSequence text = myBuilder.getOriginalText();
-
-        int start = Math.max(0, myBuilder.getCurrentOffset() - range);
-        int end = Math.min(text.length() - 1, myBuilder.getCurrentOffset() + 50 + marker.length());
-
-        return new StringBuilder(text)
-                .insert(myBuilder.getCurrentOffset(), marker)
-                .substring(start, end);
+        return StringsPackage.substringWithContext(myBuilder.getOriginalText(), myBuilder.getCurrentOffset(), myBuilder.getCurrentOffset(), 20);
     }
 }
diff --git a/compiler/util/src/org/jetbrains/jet/utils/strings.kt b/compiler/util/src/org/jetbrains/jet/utils/strings.kt
new file mode 100644
index 00000000000..d83315953c3
--- /dev/null
+++ b/compiler/util/src/org/jetbrains/jet/utils/strings.kt
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2010-2014 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 org.jetbrains.jet.utils.strings
+
+import com.intellij.openapi.util.text.StringUtil
+
+private val CARET_MARKER = "<~!!~>"
+private val BEGIN_MARKER = "<~BEGIN~>"
+private val END_MARKER = "<~END~>"
+
+public fun CharSequence.substringWithContext(beginIndex: Int, endIndex: Int, range: Int): String {
+    val start = Math.max(0, beginIndex - range)
+    val end = Math.min(this.length(), endIndex + range)
+
+    val notFromBegin = start != 0
+    val notToEnd = end != this.length()
+
+    val updatedStart = beginIndex - start
+    val updatedEnd = endIndex - start
+
+    return StringBuilder(this.toString().substring(start, end))
+            .insert(updatedEnd, if (updatedEnd == updatedStart) CARET_MARKER else END_MARKER)
+            .insert(updatedStart, if (updatedEnd == updatedStart) "" else BEGIN_MARKER)
+            .insert(0, if (notFromBegin) "<~...${position(this, start)}~>" else "")
+            .append(if (notToEnd) "<~${position(this, end)}...~>" else "").toString()
+}
+
+private fun position(str: CharSequence, offset: Int): String {
+    val line = StringUtil.offsetToLineNumber(str, offset) + 1
+    return "(line: $line)"
+}
+
+