CODEWITHSUNDEEP
javascripttypescript
Christopher Lugod
Christopher Lugod

Reputation: 23

Got error on passing method as parameter on another method inside class

class Parser {
	private tokens: Array<ITokenized>
	private token_index: number;
	private current_token: ITokenized | undefined;

	constructor(tokens: Array<ITokenized>) {
		// console.log(tokens);
		this.tokens = tokens
		this.token_index = -1;
		this.current_token = undefined
		this.next()
	}

	next() {
		this.token_index += 1;
		if (this.token_index < this.tokens.length) {
			this.current_token = this.tokens[this.token_index]
		}
		return this.current_token
	}

	public parse(): any {
		let result = this.expression();
		return result;
	}

	private factor() {
		let token = this.current_token
		if ([TOK_INT, TOK_FLOAT].includes(token?.dataType)) {
			this.next();
			return new NumberNode(token?.value).represent();
		}
	}

	private term() {
		return this.binaryOperation(this.factor, [TOK_MULTI, TOK_DIVI])
	}

	private expression() {
		return this.binaryOperation(this.term, [TOK_PLUS, TOK_MINUS])
	}

	public binaryOperation(func: Function, operator: Array<string>) {
		let leftNode, operationToken, rightNode;
		leftNode = func()
		while (operator.includes(this.current_token?.dataType)) {
			operationToken = this.current_token;
			this.next();
			rightNode = func()
			leftNode = new BinaryOperator(leftNode, operationToken?.dataType, rightNode).represent();
		}

		return leftNode;
	}
}


export default Parser;

F:\Programming-Files\hello-world\dev-projects\puCpp-programming-language\src\parser\Parser.ts:69 return this.binaryOperation(this.factor, [TOK_MULTI, TOK_DIVI]) ^ TypeError: Cannot read property 'binaryOperation' of undefined at Parser.term (F:\Programming-Files\hello-world\dev-projects\puCpp-programming-language\src\parser\Parser.ts:69:15) at Parser.binaryOperation (F:\Programming-Files\hello-world\dev-projects\puCpp-programming-language\src\parser\Parser.ts:78:14) at Parser.expression (F:\Programming-Files\hello-world\dev-projects\puCpp-programming-language\src\parser\Parser.ts:73:15) at Parser.parse (F:\Programming-Files\hello-world\dev-projects\puCpp-programming-language\src\parser\Parser.ts:56:21) at Runner.start (F:\Programming-Files\hello-world\dev-projects\puCpp-programming-language\src\lexer\Runner.ts:21:26) at F:\Programming-Files\hello-world\dev-projects\puCpp-programming-language\src\index.ts:25:46 at Interface._onLine (readline.js:306:5) at Interface._line (readline.js:656:8) at Interface._ttyWrite (readline.js:937:14) at Socket.onkeypress (readline.js:184:10)

Upvotes: 2

Views: 34

Answers (1)

ehutchllew
ehutchllew

Reputation: 958

Try explicitly binding your function arguments:

private term() {
        return this.binaryOperation(this.factor.bind(this), [TOK_MULTI, TOK_DIVI])
    }

private expression() {
        return this.binaryOperation(this.term.bind(this), [TOK_PLUS, TOK_MINUS])
    }

Upvotes: 1

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