added functions to parser

src/parser/instruction.ts

@@ -4,28 +4,32 @@ enum InstructionType
 {
     Point,
     Line,
-    Circle
+    Circle,
+    Length
 }
 
 abstract class Instruction 
 {
     public fn: InstructionType;
     public params :Parameter[];
+    private argc: number;
 
-    constructor(type: InstructionType)
+    constructor(type: InstructionType, argc: number)
     {
         this.fn = type;
+        this.argc = argc;
         this.params = [];
     }
 
     abstract eval();
+    public getParameterCount(): number { return this.argc; }
 }
 
 class PointInstruction extends Instruction
 {
     constructor()
     {
-        super(InstructionType.Point);
+        super(InstructionType.Point, 2);
     }
 
     eval()
@@ -38,7 +42,7 @@ class LineInstruction extends Instruction
 {
     constructor()
     {
-        super(InstructionType.Line);
+        super(InstructionType.Line, 2);
     }
 
     eval()
@@ -48,4 +52,36 @@ class LineInstruction extends Instruction
             this.params[1].eval()
         ];
     }
+}
+
+class CircleInstruction extends Instruction
+{
+    constructor()
+    {
+        super(InstructionType.Line, 2);
+    }
+
+    eval()
+    {
+        return [
+            this.params[0].eval(),
+            this.params[1].eval()
+        ];
+    }
+}
+
+class LengthInstruction extends Instruction
+{
+    constructor()
+    {
+        super(InstructionType.Line, 1);
+    }
+
+    eval()
+    {
+        let line = this.params[0].eval();
+        let dx = line[1].x - line[0].x;
+        let dy = line[1].y - line[0].y;
+        return Math.sqrt(Math.pow(dx, 2) + Math.pow(dy, 2));
+    }
 }