diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 64328517299..165466480a2 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -173,12 +173,12 @@ module ts {
             var lastLine = getLineStarts(currentSourceFile).length;
             var firstCommentLineIndent: number;
             for (var pos = comment.pos, currentLine = firstCommentLineAndCharacter.line; pos < comment.end; currentLine++) {
-                var nextLineStart = currentLine === lastLine ? (comment.end + 1) : getPositionFromOneBasedLineAndCharacter(currentSourceFile, currentLine + 1, /*character*/1);
+                var nextLineStart = currentLine === lastLine ? (comment.end + 1) : getPositionOfOneBasedLineAndCharacter(currentSourceFile, currentLine + 1, /*character*/1);
 
                 if (pos !== comment.pos) {
                     // If we are not emitting first line, we need to write the spaces to adjust the alignment
                     if (firstCommentLineIndent === undefined) {
-                        firstCommentLineIndent = calculateIndent(getPositionFromOneBasedLineAndCharacter(currentSourceFile, firstCommentLineAndCharacter.line, /*character*/1),
+                        firstCommentLineIndent = calculateIndent(getPositionOfOneBasedLineAndCharacter(currentSourceFile, firstCommentLineAndCharacter.line, /*character*/1),
                             comment.pos);
                     }
 
diff --git a/src/compiler/scanner.ts b/src/compiler/scanner.ts
index a7ff60ebd34..25e1ef63f6f 100644
--- a/src/compiler/scanner.ts
+++ b/src/compiler/scanner.ts
@@ -278,15 +278,15 @@ module ts {
         return result;
     }
 
-    export function getPositionFromZeroBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number {
-        return computePositionFromOneBasedLineAndCharacter(getLineStarts(sourceFile), line + 1, character + 1);
+    export function getPositionOfZeroBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number {
+        return computePositionOfOneBasedLineAndCharacter(getLineStarts(sourceFile), line + 1, character + 1);
     }
 
-    export function getPositionFromOneBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number {
-        return computePositionFromOneBasedLineAndCharacter(getLineStarts(sourceFile), line, character);
+    export function getPositionOfOneBasedLineAndCharacter(sourceFile: SourceFile, line: number, character: number): number {
+        return computePositionOfOneBasedLineAndCharacter(getLineStarts(sourceFile), line, character);
     }
 
-    export function computePositionFromOneBasedLineAndCharacter(lineStarts: number[], line: number, character: number): number {
+    export function computePositionOfOneBasedLineAndCharacter(lineStarts: number[], line: number, character: number): number {
         Debug.assert(line > 0 && line <= lineStarts.length);
         return lineStarts[line - 1] + character - 1;
     }
diff --git a/src/harness/harness.ts b/src/harness/harness.ts
index 9e4d49c267d..4a87f953ee1 100644
--- a/src/harness/harness.ts
+++ b/src/harness/harness.ts
@@ -1184,7 +1184,7 @@ module Harness {
         }
 
         export function getMinimalDiagnostic(err: ts.Diagnostic): HarnessDiagnostic {
-            var errorLineInfo = err.file ? err.file.getOneBasedLineAndCharacterFromPosition(err.start) : { line: 0, character: 0 };
+            var errorLineInfo = err.file ? err.file.getOneBasedLineAndCharacterOfPosition(err.start) : { line: 0, character: 0 };
             return {
                 fileName: err.file && err.file.fileName,
                 start: err.start,
diff --git a/src/harness/harnessLanguageService.ts b/src/harness/harnessLanguageService.ts
index f0d788a1c6b..07f9916d703 100644
--- a/src/harness/harnessLanguageService.ts
+++ b/src/harness/harnessLanguageService.ts
@@ -175,7 +175,7 @@ module Harness.LanguageService {
             assert.isTrue(line >= 1);
             assert.isTrue(col >= 1);
 
-            return ts.computePositionFromOneBasedLineAndCharacter(script.lineMap, line, col);
+            return ts.computePositionOfOneBasedLineAndCharacter(script.lineMap, line, col);
         }
 
         /**
diff --git a/src/harness/typeWriter.ts b/src/harness/typeWriter.ts
index 8747265d218..44532c6a59e 100644
--- a/src/harness/typeWriter.ts
+++ b/src/harness/typeWriter.ts
@@ -85,7 +85,7 @@ class TypeWriterWalker {
 
     private log(node: ts.Node, type: ts.Type): void {
         var actualPos = ts.skipTrivia(this.currentSourceFile.text, node.pos);
-        var lineAndCharacter = this.currentSourceFile.getOneBasedLineAndCharacterFromPosition(actualPos);
+        var lineAndCharacter = this.currentSourceFile.getOneBasedLineAndCharacterOfPosition(actualPos);
         var sourceText = ts.getTextOfNodeFromSourceText(this.currentSourceFile.text, node);
         
         // If we got an unknown type, we temporarily want to fall back to just pretending the name
diff --git a/src/services/breakpoints.ts b/src/services/breakpoints.ts
index 68932e32fad..492cc7866e9 100644
--- a/src/services/breakpoints.ts
+++ b/src/services/breakpoints.ts
@@ -14,17 +14,17 @@ module ts.BreakpointResolver {
         }
 
         var tokenAtLocation = getTokenAtPosition(sourceFile, position);
-        var lineOfPosition = sourceFile.getOneBasedLineAndCharacterFromPosition(position).line;
-        if (sourceFile.getOneBasedLineAndCharacterFromPosition(tokenAtLocation.getStart()).line > lineOfPosition) {
+        var lineOfPosition = sourceFile.getZeroBasedLineAndCharacterOfPosition(position).line;
+        if (sourceFile.getZeroBasedLineAndCharacterOfPosition(tokenAtLocation.getStart()).line > lineOfPosition) {
             // Get previous token if the token is returned starts on new line
-            // eg: var x =10; |--- curser is here
+            // eg: var x =10; |--- cursor is here
             //     var y = 10; 
             // token at position will return var keyword on second line as the token but we would like to use 
             // token on same line if trailing trivia (comments or white spaces on same line) part of the last token on that line
             tokenAtLocation = findPrecedingToken(tokenAtLocation.pos, sourceFile);
 
             // Its a blank line
-            if (!tokenAtLocation || sourceFile.getOneBasedLineAndCharacterFromPosition(tokenAtLocation.getEnd()).line !== lineOfPosition) {
+            if (!tokenAtLocation || sourceFile.getZeroBasedLineAndCharacterOfPosition(tokenAtLocation.getEnd()).line !== lineOfPosition) {
                 return undefined;
             }
         }
@@ -42,7 +42,7 @@ module ts.BreakpointResolver {
         }
 
         function spanInNodeIfStartsOnSameLine(node: Node, otherwiseOnNode?: Node): TextSpan {
-            if (node && lineOfPosition === sourceFile.getOneBasedLineAndCharacterFromPosition(node.getStart()).line) {
+            if (node && lineOfPosition === sourceFile.getZeroBasedLineAndCharacterOfPosition(node.getStart()).line) {
                 return spanInNode(node);
             }
             return spanInNode(otherwiseOnNode);
diff --git a/src/services/formatting/formatting.ts b/src/services/formatting/formatting.ts
index 1d3410c189c..322c36bf7ad 100644
--- a/src/services/formatting/formatting.ts
+++ b/src/services/formatting/formatting.ts
@@ -67,7 +67,7 @@ module ts.formatting {
     }
 
     export function formatOnEnter(position: number, sourceFile: SourceFile, rulesProvider: RulesProvider, options: FormatCodeOptions): TextChange[] {
-        var line = sourceFile.getOneBasedLineAndCharacterFromPosition(position).line;
+        var line = sourceFile.getOneBasedLineAndCharacterOfPosition(position).line;
         if (line === 1) {
             return [];
         }
@@ -283,7 +283,7 @@ module ts.formatting {
         var previousLine = Constants.Unknown;
         var childKind = SyntaxKind.Unknown;
         while (n) {
-            var line = sourceFile.getOneBasedLineAndCharacterFromPosition(n.getStart(sourceFile)).line;
+            var line = sourceFile.getOneBasedLineAndCharacterOfPosition(n.getStart(sourceFile)).line;
             if (previousLine !== Constants.Unknown && line !== previousLine) {
                 break;
             }
@@ -327,7 +327,7 @@ module ts.formatting {
         formattingScanner.advance();
 
         if (formattingScanner.isOnToken()) {
-            var startLine = sourceFile.getOneBasedLineAndCharacterFromPosition(enclosingNode.getStart(sourceFile)).line;
+            var startLine = sourceFile.getOneBasedLineAndCharacterOfPosition(enclosingNode.getStart(sourceFile)).line;
             var delta = getOwnOrInheritedDelta(enclosingNode, options, sourceFile);
             processNode(enclosingNode, enclosingNode, startLine, initialIndentation, delta);
         }
@@ -357,7 +357,7 @@ module ts.formatting {
                 }
             }
             else {
-                var startLine = sourceFile.getOneBasedLineAndCharacterFromPosition(startPos).line;
+                var startLine = sourceFile.getOneBasedLineAndCharacterOfPosition(startPos).line;
                 var startLinePosition = getLineStartPositionForPosition(startPos, sourceFile);
                 var column = SmartIndenter.findFirstNonWhitespaceColumn(startLinePosition, startPos, sourceFile, options);
                 if (startLine !== parentStartLine || startPos === column) {
@@ -521,7 +521,7 @@ module ts.formatting {
 
                 var childStartPos = child.getStart(sourceFile);
 
-                var childStart = sourceFile.getOneBasedLineAndCharacterFromPosition(childStartPos);
+                var childStart = sourceFile.getOneBasedLineAndCharacterOfPosition(childStartPos);
 
                 // if child is a list item - try to get its indentation
                 var childIndentationAmount = Constants.Unknown;
@@ -594,7 +594,7 @@ module ts.formatting {
                         }
                         else if (tokenInfo.token.kind === listStartToken) {
                             // consume list start token
-                            startLine = sourceFile.getOneBasedLineAndCharacterFromPosition(tokenInfo.token.pos).line;
+                            startLine = sourceFile.getOneBasedLineAndCharacterOfPosition(tokenInfo.token.pos).line;
                             var indentation =
                                 computeIndentation(tokenInfo.token, startLine, Constants.Unknown, parent, parentDynamicIndentation, startLine);
 
@@ -641,7 +641,7 @@ module ts.formatting {
                 var lineAdded: boolean;
                 var isTokenInRange = rangeContainsRange(originalRange, currentTokenInfo.token);
 
-                var tokenStart = sourceFile.getOneBasedLineAndCharacterFromPosition(currentTokenInfo.token.pos);
+                var tokenStart = sourceFile.getOneBasedLineAndCharacterOfPosition(currentTokenInfo.token.pos);
                 if (isTokenInRange) {
                     var rangeHasError = rangeContainsError(currentTokenInfo.token);
                     // save prevStartLine since processRange will overwrite this value with current ones
@@ -674,7 +674,7 @@ module ts.formatting {
                                 continue;
                             }
 
-                            var triviaStartLine = sourceFile.getOneBasedLineAndCharacterFromPosition(triviaItem.pos).line;
+                            var triviaStartLine = sourceFile.getOneBasedLineAndCharacterOfPosition(triviaItem.pos).line;
                             switch (triviaItem.kind) {
                                 case SyntaxKind.MultiLineCommentTrivia:
                                     var commentIndentation = dynamicIndentation.getIndentationForComment(currentTokenInfo.token.kind);
@@ -712,7 +712,7 @@ module ts.formatting {
             for (var i = 0, len = trivia.length; i < len; ++i) {
                 var triviaItem = trivia[i];
                 if (isComment(triviaItem.kind) && rangeContainsRange(originalRange, triviaItem)) {
-                    var triviaItemStart = sourceFile.getOneBasedLineAndCharacterFromPosition(triviaItem.pos);
+                    var triviaItemStart = sourceFile.getOneBasedLineAndCharacterOfPosition(triviaItem.pos);
                     processRange(triviaItem, triviaItemStart, parent, contextNode, dynamicIndentation);
                 }
             }
@@ -729,7 +729,7 @@ module ts.formatting {
             if (!rangeHasError && !previousRangeHasError) {
                 if (!previousRange) {
                     // trim whitespaces starting from the beginning of the span up to the current line
-                    var originalStart = sourceFile.getOneBasedLineAndCharacterFromPosition(originalRange.pos);
+                    var originalStart = sourceFile.getOneBasedLineAndCharacterOfPosition(originalRange.pos);
                     trimTrailingWhitespacesForLines(originalStart.line, rangeStart.line);
                 }
                 else {
@@ -807,7 +807,7 @@ module ts.formatting {
                 recordReplace(pos, 0, indentationString);
             }
             else {
-                var tokenStart = sourceFile.getOneBasedLineAndCharacterFromPosition(pos);
+                var tokenStart = sourceFile.getOneBasedLineAndCharacterOfPosition(pos);
                 if (indentation !== tokenStart.character - 1) {
                     var startLinePosition = getStartPositionOfLine(tokenStart.line, sourceFile);
                     recordReplace(startLinePosition, tokenStart.character - 1, indentationString);
@@ -817,8 +817,8 @@ module ts.formatting {
 
         function indentMultilineComment(commentRange: TextRange, indentation: number, firstLineIsIndented: boolean) {
             // split comment in lines
-            var startLine = sourceFile.getOneBasedLineAndCharacterFromPosition(commentRange.pos).line;
-            var endLine = sourceFile.getOneBasedLineAndCharacterFromPosition(commentRange.end).line;
+            var startLine = sourceFile.getOneBasedLineAndCharacterOfPosition(commentRange.pos).line;
+            var endLine = sourceFile.getOneBasedLineAndCharacterOfPosition(commentRange.end).line;
 
             if (startLine === endLine) {
                 if (!firstLineIsIndented) {
diff --git a/src/services/formatting/formattingContext.ts b/src/services/formatting/formattingContext.ts
index c6680b4a80e..0b9372d86e2 100644
--- a/src/services/formatting/formattingContext.ts
+++ b/src/services/formatting/formattingContext.ts
@@ -71,8 +71,8 @@ module ts.formatting {
 
         public TokensAreOnSameLine(): boolean {
             if (this.tokensAreOnSameLine === undefined) {
-                var startLine = this.sourceFile.getOneBasedLineAndCharacterFromPosition(this.currentTokenSpan.pos).line;
-                var endLine = this.sourceFile.getOneBasedLineAndCharacterFromPosition(this.nextTokenSpan.pos).line;
+                var startLine = this.sourceFile.getOneBasedLineAndCharacterOfPosition(this.currentTokenSpan.pos).line;
+                var endLine = this.sourceFile.getOneBasedLineAndCharacterOfPosition(this.nextTokenSpan.pos).line;
                 this.tokensAreOnSameLine = (startLine == endLine);
             }
 
@@ -96,8 +96,8 @@ module ts.formatting {
         }
 
         private NodeIsOnOneLine(node: Node): boolean {
-            var startLine = this.sourceFile.getOneBasedLineAndCharacterFromPosition(node.getStart(this.sourceFile)).line;
-            var endLine = this.sourceFile.getOneBasedLineAndCharacterFromPosition(node.getEnd()).line;
+            var startLine = this.sourceFile.getOneBasedLineAndCharacterOfPosition(node.getStart(this.sourceFile)).line;
+            var endLine = this.sourceFile.getOneBasedLineAndCharacterOfPosition(node.getEnd()).line;
             return startLine == endLine;
         }
 
@@ -105,8 +105,8 @@ module ts.formatting {
             var openBrace = findChildOfKind(node, SyntaxKind.OpenBraceToken, this.sourceFile);
             var closeBrace = findChildOfKind(node, SyntaxKind.CloseBraceToken, this.sourceFile);
             if (openBrace && closeBrace) {
-                var startLine = this.sourceFile.getOneBasedLineAndCharacterFromPosition(openBrace.getEnd()).line;
-                var endLine = this.sourceFile.getOneBasedLineAndCharacterFromPosition(closeBrace.getStart(this.sourceFile)).line;
+                var startLine = this.sourceFile.getOneBasedLineAndCharacterOfPosition(openBrace.getEnd()).line;
+                var endLine = this.sourceFile.getOneBasedLineAndCharacterOfPosition(closeBrace.getStart(this.sourceFile)).line;
                 return startLine === endLine;
             }
             return false;
diff --git a/src/services/formatting/smartIndenter.ts b/src/services/formatting/smartIndenter.ts
index 629c82ef0a8..35be18910e3 100644
--- a/src/services/formatting/smartIndenter.ts
+++ b/src/services/formatting/smartIndenter.ts
@@ -24,7 +24,7 @@ module ts.formatting {
                 return 0;
             }
 
-            var lineAtPosition = sourceFile.getOneBasedLineAndCharacterFromPosition(position).line;
+            var lineAtPosition = sourceFile.getOneBasedLineAndCharacterOfPosition(position).line;
 
             if (precedingToken.kind === SyntaxKind.CommaToken && precedingToken.parent.kind !== SyntaxKind.BinaryExpression) {
                 // previous token is comma that separates items in list - find the previous item and try to derive indentation from it
@@ -74,7 +74,7 @@ module ts.formatting {
         }
 
         export function getIndentationForNode(n: Node, ignoreActualIndentationRange: TextRange, sourceFile: SourceFile, options: FormatCodeOptions): number {
-            var start = sourceFile.getOneBasedLineAndCharacterFromPosition(n.getStart(sourceFile));
+            var start = sourceFile.getOneBasedLineAndCharacterOfPosition(n.getStart(sourceFile));
             return getIndentationForNodeWorker(n, start, ignoreActualIndentationRange, /*indentationDelta*/ 0, sourceFile, options);
         }
 
@@ -135,10 +135,10 @@ module ts.formatting {
         function getParentStart(parent: Node, child: Node, sourceFile: SourceFile): LineAndCharacter {
             var containingList = getContainingList(child, sourceFile);
             if (containingList) {
-                return sourceFile.getOneBasedLineAndCharacterFromPosition(containingList.pos);
+                return sourceFile.getOneBasedLineAndCharacterOfPosition(containingList.pos);
             }
 
-            return sourceFile.getOneBasedLineAndCharacterFromPosition(parent.getStart(sourceFile));
+            return sourceFile.getOneBasedLineAndCharacterOfPosition(parent.getStart(sourceFile));
         }
 
         /*
@@ -204,7 +204,7 @@ module ts.formatting {
         }
 
         function getStartLineAndCharacterForNode(n: Node, sourceFile: SourceFile): LineAndCharacter {
-            return sourceFile.getOneBasedLineAndCharacterFromPosition(n.getStart(sourceFile));
+            return sourceFile.getOneBasedLineAndCharacterOfPosition(n.getStart(sourceFile));
         }
 
         function positionBelongsToNode(candidate: Node, position: number, sourceFile: SourceFile): boolean {
@@ -292,7 +292,7 @@ module ts.formatting {
                     continue;
                 }
                 // skip list items that ends on the same line with the current list element
-                var prevEndLine = sourceFile.getOneBasedLineAndCharacterFromPosition(list[i].end).line;
+                var prevEndLine = sourceFile.getOneBasedLineAndCharacterOfPosition(list[i].end).line;
                 if (prevEndLine !== lineAndCharacter.line) {
                     return findColumnForFirstNonWhitespaceCharacterInLine(lineAndCharacter, sourceFile, options);
                 }
@@ -303,7 +303,7 @@ module ts.formatting {
         }
 
         function findColumnForFirstNonWhitespaceCharacterInLine(lineAndCharacter: LineAndCharacter, sourceFile: SourceFile, options: EditorOptions): number {
-            var lineStart = sourceFile.getPositionFromOneBasedLineAndCharacter(lineAndCharacter.line, 1);
+            var lineStart = sourceFile.getPositionOfOneBasedLineAndCharacter(lineAndCharacter.line, 1);
             return findFirstNonWhitespaceColumn(lineStart, lineStart + lineAndCharacter.character, sourceFile, options);
         }
 
diff --git a/src/services/services.ts b/src/services/services.ts
index 04e846e88e9..33fde9e005e 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -61,9 +61,10 @@ module ts {
         scriptSnapshot: IScriptSnapshot;
         nameTable: Map<string>;
         getNamedDeclarations(): Declaration[];
-        getOneBasedLineAndCharacterFromPosition(pos: number): LineAndCharacter;
+        getZeroBasedLineAndCharacterOfPosition(pos: number): LineAndCharacter;
+        getOneBasedLineAndCharacterOfPosition(pos: number): LineAndCharacter;
         getLineStarts(): number[];
-        getPositionFromOneBasedLineAndCharacter(line: number, character: number): number;
+        getPositionOfOneBasedLineAndCharacter(line: number, character: number): number;
         update(newText: string, textChangeRange: TextChangeRange): SourceFile;
     }
 
@@ -612,7 +613,7 @@ module ts {
                     }
 
                     if (paramHelpStringMargin === undefined) {
-                        paramHelpStringMargin = sourceFile.getOneBasedLineAndCharacterFromPosition(firstLineParamHelpStringPos).character - 1;
+                        paramHelpStringMargin = sourceFile.getOneBasedLineAndCharacterOfPosition(firstLineParamHelpStringPos).character - 1;
                     }
 
                     // Now consume white spaces max 
@@ -750,16 +751,20 @@ module ts {
             return updateSourceFile(this, newText, textChangeRange);
         }
 
-        public getOneBasedLineAndCharacterFromPosition(position: number): LineAndCharacter {
-            return getOneBasedLineAndCharacterOfPosition(this, position);
+        public getZeroBasedLineAndCharacterOfPosition(position: number): LineAndCharacter {
+            return ts.getZeroBasedLineAndCharacterOfPosition(this, position);
+        }
+
+        public getOneBasedLineAndCharacterOfPosition(position: number): LineAndCharacter {
+            return ts.getOneBasedLineAndCharacterOfPosition(this, position);
         }
 
         public getLineStarts(): number[] {
             return getLineStarts(this);
         }
 
-        public getPositionFromOneBasedLineAndCharacter(line: number, character: number): number {
-            return getPositionFromOneBasedLineAndCharacter(this, line, character);
+        public getPositionOfOneBasedLineAndCharacter(line: number, character: number): number {
+            return ts.getPositionOfOneBasedLineAndCharacter(this, line, character);
         }
 
         public getNamedDeclarations() {
diff --git a/src/services/utilities.ts b/src/services/utilities.ts
index 1576003747b..711fc0fde8d 100644
--- a/src/services/utilities.ts
+++ b/src/services/utilities.ts
@@ -39,7 +39,7 @@ module ts {
 
     export function getLineStartPositionForPosition(position: number, sourceFile: SourceFile): number {
         var lineStarts = sourceFile.getLineStarts();
-        var line = sourceFile.getOneBasedLineAndCharacterFromPosition(position).line;
+        var line = sourceFile.getOneBasedLineAndCharacterOfPosition(position).line;
         return lineStarts[line - 1];
     }