Add AST

src/main.ts

@@ -1,4 +1,13 @@
 import { Lexer } from './parser/Lexer'
+import { BinaryExpression } from './parser/ast/BinaryExpression'
+import { Expression } from './parser/ast/Expression'
+import { Operator } from './parser/ast/Operator'
+import { ValueExpression } from './parser/ast/ValueExpression'
+
+let expr1: Expression = new ValueExpression(10)
+let expr2: Expression = new ValueExpression(20)
+let exprAdd: Expression = new BinaryExpression(Operator.ADD, expr1, expr2)
+console.log(exprAdd.eval());
 
 const tokens = new Lexer("10 / 2").process().getTokens();
-console.log(tokens);
+console.log(tokens)

src/parser/ast/BinaryExpression.ts

@@ -0,0 +1,18 @@
+import { Expression } from "./Expression";
+import { BinaryFunction } from "./Operator";
+
+export class BinaryExpression implements Expression {
+    constructor(
+        private readonly op: BinaryFunction,
+        private readonly left: Expression,
+        private readonly right: Expression
+    ) {
+        this.op = op;
+        this.left = left;
+        this.right = right;
+    }
+
+    public eval(): any {
+        return this.op(this.left.eval(), this.right.eval());
+    }
+}

src/parser/ast/Expression.ts

@@ -0,0 +1,3 @@
+export interface Expression {
+    eval(): any
+}

src/parser/ast/Operator.ts

@@ -0,0 +1,19 @@
+export type BinaryFunction = (leftVal: any, rightVal: any) => any;
+
+export const Operator = {
+    ADD         : (leftVal: any, rightVal: any) => leftVal + rightVal,
+    SUBTRACT    : (leftVal: any, rightVal: any) => leftVal - rightVal,
+    MULTIPLY    : (leftVal: any, rightVal: any) => leftVal * rightVal,
+    DIVIDE      : (leftVal: any, rightVal: any) => leftVal / rightVal,
+    
+    EQUALS      : (leftVal: any, rightVal: any) => (leftVal == rightVal) ? 1 : 0,
+    NOTEQUALS   : (leftVal: any, rightVal: any) => (leftVal != rightVal) ? 1 : 0,
+    
+    GT          : (leftVal: any, rightVal: any) => (leftVal > rightVal) ? 1 : 0,
+    LT          : (leftVal: any, rightVal: any) => (leftVal < rightVal) ? 1 : 0,
+    GTEQ        : (leftVal: any, rightVal: any) => (leftVal >= rightVal) ? 1 : 0,
+    LTEQ        : (leftVal: any, rightVal: any) => (leftVal <= rightVal) ? 1 : 0,
+    
+    BOOLEAN_OR  : (leftVal: any, rightVal: any) => { ((leftVal != 0) || (rightVal != 0)) ? 1 : 0; },
+    BOOLEAN_AND : (leftVal: any, rightVal: any) => { ((leftVal != 0) && (rightVal != 0)) ? 1 : 0; }
+};

src/parser/ast/ValueExpression.ts

@@ -0,0 +1,11 @@
+import { Expression } from "./Expression";
+
+export class ValueExpression implements Expression {
+    constructor(private readonly value: any) {
+        this.value = value;
+    }
+
+    public eval(): any  {
+        return this.value;
+    }
+}

src/parser/ast/VariableExpression.ts

@@ -0,0 +1,12 @@
+import { Variables } from "../../runtime/Variables";
+import { Expression } from "./Expression";
+
+export class VariableExpression implements Expression {
+    constructor(private readonly variable: string) {
+        this.variable = variable;
+    }
+
+    public eval(): string { // TODO context 
+        return Variables.getVariable(this.variable);
+    }
+}

src/runtime/Variables.ts

@@ -0,0 +1,13 @@
+import { VariablesHolder } from "./VariablesHolder";
+
+export class Variables {
+    private static holder: VariablesHolder = new VariablesHolder();
+
+    public static getVariable(name: string): any {
+        return Variables.holder.getVariable(name);
+    }
+
+    public static setVariable(name: string, value: any): void {
+        Variables.holder.setVariable(name, value);
+    }
+}

src/runtime/VariablesHolder.ts

@@ -0,0 +1,26 @@
+export class VariablesHolder {
+
+    private variables: object
+
+    constructor() {
+        this.variables = {};
+    }
+
+    public init(): void {
+        this.variables = {
+            "True": 1,
+            "False": 0
+        };
+    }
+    
+    public getVariable(name: string): any {
+        if (name in this.variables) {
+            return this.variables[name];
+        }
+        return 0;
+    }
+
+    public setVariable(name: string, value: any): void {
+        this.variables[name] = value;
+    }
+}