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/*
* Copyright (C) 2016-2017 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
"use strict";
const Basic = {};
Basic.NumberApply = function(state)
{
// I'd call this arguments but we're in strict mode.
let parameters = this.parameters.map(value => value.evaluate(state));
return state.getValue(this.name, parameters.length).apply(state, parameters);
};
Basic.Variable = function(state)
{
let parameters = this.parameters.map(value => value.evaluate(state));
return state.getValue(this.name, parameters.length).leftApply(state, parameters);
}
Basic.Const = function(state)
{
return this.value;
}
Basic.NumberPow = function(state)
{
return Math.pow(this.left.evaluate(state), this.right.evaluate(state));
}
Basic.NumberMul = function(state)
{
return this.left.evaluate(state) * this.right.evaluate(state);
}
Basic.NumberDiv = function(state)
{
return this.left.evaluate(state) / this.right.evaluate(state);
}
Basic.NumberNeg = function(state)
{
return -this.term.evaluate(state);
}
Basic.NumberAdd = function(state)
{
return this.left.evaluate(state) + this.right.evaluate(state);
}
Basic.NumberSub = function(state)
{
return this.left.evaluate(state) - this.right.evaluate(state);
}
Basic.StringVar = function(state)
{
let value = state.stringValues.get(this.name);
if (value == null)
state.abort("Could not find string variable " + this.name);
return value;
}
Basic.Equals = function(state)
{
return this.left.evaluate(state) == this.right.evaluate(state);
}
Basic.NotEquals = function(state)
{
return this.left.evaluate(state) != this.right.evaluate(state);
}
Basic.LessThan = function(state)
{
return this.left.evaluate(state) < this.right.evaluate(state);
}
Basic.GreaterThan = function(state)
{
return this.left.evaluate(state) > this.right.evaluate(state);
}
Basic.LessEqual = function(state)
{
return this.left.evaluate(state) <= this.right.evaluate(state);
}
Basic.GreaterEqual = function(state)
{
return this.left.evaluate(state) >= this.right.evaluate(state);
}
Basic.GoTo = function*(state)
{
state.nextLineNumber = this.target;
}
Basic.GoSub = function*(state)
{
state.subStack.push(state.nextLineNumber);
state.nextLineNumber = this.target;
}
Basic.Def = function*(state)
{
state.validate(!state.values.has(this.name), "Cannot redefine function");
state.values.set(this.name, new NumberFunction(this.parameters, this.expression));
}
Basic.Let = function*(state)
{
this.variable.evaluate(state).assign(this.expression.evaluate(state));
}
Basic.If = function*(state)
{
if (this.condition.evaluate(state))
state.nextLineNumber = this.target;
}
Basic.Return = function*(state)
{
this.validate(state.subStack.length, "Not in a subroutine");
this.nextLineNumber = state.subStack.pop();
}
Basic.Stop = function*(state)
{
state.nextLineNumber = null;
}
Basic.On = function*(state)
{
let index = this.expression.evaluate(state);
if (!(index >= 1) || !(index <= this.targets.length))
state.abort("Index out of bounds: " + index);
this.nextLineNumber = this.targets[Math.floor(index)];
}
Basic.For = function*(state)
{
let sideState = state.getSideState(this);
sideState.variable = state.getValue(this.variable, 0).leftApply(state, []);
sideState.initialValue = this.initial.evaluate(state);
sideState.limitValue = this.limit.evaluate(state);
sideState.stepValue = this.step.evaluate(state);
sideState.variable.assign(sideState.initialValue);
sideState.shouldStop = function() {
return (sideState.variable.value - sideState.limitValue) * Math.sign(sideState.stepValue) > 0;
};
if (sideState.shouldStop())
this.nextLineNumber = this.target.lineNumber + 1;
}
Basic.Next = function*(state)
{
let sideState = state.getSideState(this.target);
sideState.variable.assign(sideState.variable.value + sideState.stepValue);
if (sideState.shouldStop())
return;
state.nextLineNumber = this.target.lineNumber + 1;
}
Basic.Next.isBlockEnd = true;
Basic.Print = function*(state)
{
let string = "";
for (let item of this.items) {
switch (item.kind) {
case "comma":
while (string.length % 14)
string += " ";
break;
case "tab": {
let value = item.value.evaluate(state);
value = Math.max(Math.round(value), 1);
while (string.length % value)
string += " ";
break;
}
case "string":
case "number":
string += item.value.evaluate(state);
break;
default:
throw new Error("Bad item kind: " + item.kind);
}
}
yield {kind: "output", string};
}
Basic.Input = function*(state)
{
let results = yield {kind: "input", numItems: this.items.length};
state.validate(results != null && results.length == this.items.length, "Input did not get the right number of items");
for (let i = 0; i < results.length; ++i)
this.items[i].evaluate(state).assign(results[i]);
}
Basic.Read = function*(state)
{
for (let item of this.items) {
state.validate(state.dataIndex < state.program.data.length, "Attempting to read past the end of data");
item.assign(state.program.data[state.dataIndex++]);
}
}
Basic.Restore = function*(state)
{
state.dataIndex = 0;
}
Basic.Dim = function*(state)
{
for (let item of this.items) {
state.validate(!state.values.has(item.name), "Variable " + item.name + " already exists");
state.validate(item.bounds.length, "Dim statement is for arrays");
state.values.set(item.name, new NumberArray(item.bounds.map(bound => bound + 1)));
}
}
Basic.Randomize = function*(state)
{
state.rng = createRNGWithRandomSeed();
}
Basic.End = function*(state)
{
state.nextLineNumber = null;
}
Basic.End.isBlockEnd = true;
Basic.Program = function* programGenerator(state)
{
state.validate(state.program == this, "State must match program");
let maxLineNumber = Math.max(...this.statements.keys());
while (state.nextLineNumber != null) {
state.validate(state.nextLineNumber <= maxLineNumber, "Went out of bounds of the program");
let statement = this.statements.get(state.nextLineNumber++);
if (statement == null || statement.process == null)
continue;
state.statement = statement;
yield* statement.process(state);
}
}