TypeScriptToLua · Perryvw · Dec 9, 2018 · Dec 6, 2018 · Dec 9, 2018 · Dec 9, 2018
diff --git a/src/LuaNode.ts b/src/LuaNode.ts
@@ -0,0 +1,14 @@
+import * as ts from "typescript";
+
+export enum LuaSyntaxKind {
+    ConcatExpression = 10000,
+    FunctionCallExpression,
+    MethodCallExpression,
+}
+
+export interface LuaNode extends ts.Node {
+    luaKind: LuaSyntaxKind;
+}
+
+export type LuaConcatExpression = LuaNode & ts.BinaryExpression;
+export type LuaCallExpression = LuaNode & ts.CallExpression;
diff --git a/src/TSHelper.ts b/src/TSHelper.ts
@@ -1,5 +1,6 @@
 import * as ts from "typescript";
 import { Decorator, DecoratorKind } from "./Decorator";
+import { TSTLErrors } from "./Errors";
 
 export class TSHelper {
 
@@ -220,6 +221,26 @@ export class TSHelper {
         return [false, null];
     }
 
+    public static isCompoundPrefixUnaryOperator(node: ts.PrefixUnaryExpression): boolean {
+        return node.operator !== ts.SyntaxKind.ExclamationToken
+               && node.operator !== ts.SyntaxKind.MinusToken
+               && node.operator !== ts.SyntaxKind.PlusToken
+               && node.operator !== ts.SyntaxKind.TildeToken;
+    }
+
+    public static getUnaryCompoundAssignmentOperator(node: ts.PrefixUnaryExpression | ts.PostfixUnaryExpression)
+        : ts.BinaryOperator {
+        switch (node.operator) {
+            case ts.SyntaxKind.PlusPlusToken:
+                return ts.SyntaxKind.PlusToken;
+            case ts.SyntaxKind.MinusMinusToken:
+                return ts.SyntaxKind.MinusToken;
+            default:
+                throw TSTLErrors.UnsupportedKind(
+                    `unary ${ts.isPrefixUnaryExpression(node) ? "prefix" : "postfix"} operator`, node.operator, node);
+        }
+    }
+
     public static isExpressionStatement(node: ts.Expression): boolean {
         return node.parent === undefined
             || ts.isExpressionStatement(node.parent)

diff --git a/src/TransformHelper.ts b/src/TransformHelper.ts
@@ -1,4 +1,5 @@
 import * as ts from "typescript";
+import { LuaCallExpression, LuaConcatExpression, LuaNode, LuaSyntaxKind } from "./LuaNode";
 
 export class TransformHelper {
     // Helper to create simple lua variable statement;
@@ -18,6 +19,24 @@ export class TransformHelper {
         return this.createLuaVariableStatement(identifier, requireCall);
     }
 
+    public static createLuaConcatExpression(left: ts.Expression, right: ts.Expression): LuaConcatExpression {
+        const node = ts.createAdd(left, right) as LuaConcatExpression;
+        node.luaKind = LuaSyntaxKind.ConcatExpression;
+        return node;
+    }
+
+    public static createLuaCallExpression(expression: ts.Expression,
+                                          argumentsArray: ReadonlyArray<ts.Expression>,
+                                          isMethod: boolean): LuaCallExpression {
+        const node = ts.createCall(expression, undefined, argumentsArray) as LuaCallExpression;
+        node.luaKind = isMethod ? LuaSyntaxKind.MethodCallExpression : LuaSyntaxKind.FunctionCallExpression;
+        return node;
+    }
+
+    public static isLuaNode<T extends ts.Node>(node: T): node is LuaNode & T {
+        return (node as LuaNode & T).luaKind !== undefined;
+    }
+
     public static flatten<T>(arr: T[]): T[] {
         const flat = [].concat(...arr);
         return flat.some(Array.isArray) ? this.flatten(flat) : flat;