@powerlang/egg-js/interpreter/EggIterativeInterpreter.js

A Smalltalk VM that runs on top of JavaScript

import EggEvaluator from './EggEvaluator.js';


let EggIterativeInterpreter = class extends EggEvaluator {

	constructor() {
		super();
		this._regR = nil;
	}

	evaluate() {
		return this.subclassResponsibility();
	}

	hasFinished() {
		return this._context.hasFinished();
	}

	initializeUndermessages() {
		super.initializeUndermessages();
		this._undermessages.at_put_("_restart", this.underprimitiveRestart());
		return this;
	}

	prepareDispatch_(dispatch) {
		this.subclassResponsibility();
		return this;
	}

	prepareForBlock_(sblock) {
		return this.subclassResponsibility();
	}

	regR_(anObject) {
		this._regR = anObject;
		return this;
	}

	unboundAssignment_with_(aBinding, assignees) {
		if (assignees.size()._greaterThan(1))
		{
			this.error_("unbound name with multiple assignments not yet supported")
		}
		;
		this.doesNotKnow_assigned_(aBinding.name(), this._regR);
		return this;
	}

	underprimitiveRestart() {
		return this.subclassResponsibility();
	}

	visitBlock_(anSBlock) {
		this._regR = this._context.captureClosure_(anSBlock);
		return this;
	}

	visitIdentifier_(anSIdentifier) {
		let binding;
		const _home =  {};
		try {
			binding = anSIdentifier.binding();
			this._regR = binding.valueWithin_ifUnbound_(this._context, () => {
				throw [_home, this.doesNotKnow_(binding.name())]
			});
			return this;
		} catch(e) { if (e[0] == _home) return e[1]; else throw(e); }
	}

	visitLiteral_(anSLiteral) {
		this._regR = this._runtime.literalFor_(anSLiteral.value());
		return this;
	}

	visitOpAssign_(anSOpAssign) {
		let assignees, binding;
		assignees = anSOpAssign.assignees();
		assignees.do_((identifier) => {
			binding = identifier.binding();
			return binding.assign_within_ifUnbound_(this._regR, this._context, () => {
				return this.unboundAssignment_with_(binding, assignees)
			})
		});
		return this;
	}

	visitOpDropToS_(anSOpDropToS) {
		this._context.dropOperands_(anSOpDropToS.count());
		return this;
	}

	visitOpLoadRfromFrame_(anSOpLoadRfromFrame) {
		this._regR = this._context.stackTemporaryAt_(anSOpLoadRfromFrame.index());
		return this;
	}

	visitOpLoadRfromStack_(anSOpLoadRfromStack) {
		this._regR = this._context.operandAt_(anSOpLoadRfromStack.index());
		return this;
	}

	visitOpLoadRwithNil_(anSOpLoadRwithNil) {
		this._regR = this._nilObj;
		return this;
	}

	visitOpLoadRwithSelf_(anSOpLoadRwithSelf) {
		this._regR = this._context.self();
		return this;
	}

	visitOpPushR_(anSOpPushR) {
		this._context.pushOperand_(this._regR);
		return this;
	}

	visitOpStoreRintoFrame_(anSOpStoreRintoFrame) {
		this._context.stackTemporaryAt_put_(anSOpStoreRintoFrame.index(), this._regR);
		return this;
	}

}

export default EggIterativeInterpreter