8bitworkshop/src/common/basic/runtime.ts

647 lines
21 KiB
TypeScript

import * as basic from "./compiler";
import { EmuHalt } from "../emu";
function isLiteral(arg: basic.Expr): arg is basic.Literal {
return (arg as any).value != null;
}
function isLookup(arg: basic.Expr): arg is basic.IndOp {
return (arg as any).name != null;
}
function isBinOp(arg: basic.Expr): arg is basic.BinOp {
return (arg as any).op != null && (arg as any).left != null && (arg as any).right != null;
}
function isUnOp(arg: basic.Expr): arg is basic.UnOp {
return (arg as any).op != null && (arg as any).expr != null;
}
class ExprOptions {
check: boolean;
isconst?: boolean;
locals?: string[];
}
interface CompiledStatement {
$run?: () => void;
}
export class BASICRuntime {
program : basic.BASICProgram;
allstmts : basic.Statement[];
line2pc : number[];
pc2line : Map<number,number>;
label2lineidx : {[label : string] : number};
label2pc : {[label : string] : number};
datums : basic.Literal[];
curpc : number;
dataptr : number;
vars : {};
arrays : {};
forLoops : {};
returnStack : number[];
column : number;
abase : number; // array base
running : boolean = false;
exited : boolean = false;
trace : boolean = false;
load(program: basic.BASICProgram) {
this.program = program;
this.label2lineidx = {};
this.label2pc = {};
this.allstmts = [];
this.line2pc = [];
this.pc2line = new Map();
this.datums = [];
// TODO: lines start @ 1?
program.lines.forEach((line, idx) => {
// make lookup tables
if (line.label != null) this.label2lineidx[line.label] = idx;
if (line.label != null) this.label2pc[line.label] = this.allstmts.length;
this.line2pc.push(this.allstmts.length);
this.pc2line.set(this.allstmts.length, idx);
// combine all statements into single list
line.stmts.forEach((stmt) => this.allstmts.push(stmt));
// parse DATA literals
line.stmts.filter((stmt) => stmt.command == 'DATA').forEach((datastmt) => {
(datastmt as basic.DATA_Statement).datums.forEach(d => {
var functext = this.expr2js(d, {check:true, isconst:true});
// TODO: catch exceptions
// TODO: any value doing this ahead of time?
var value = new Function(`return ${functext};`).bind(this)();
this.datums.push({value:value});
});
});
// TODO: compile statements?
//line.stmts.forEach((stmt) => this.compileStatement(stmt));
});
}
reset() {
this.curpc = 0;
this.dataptr = 0;
this.vars = {};
this.arrays = {};
this.forLoops = {};
this.returnStack = [];
this.column = 0;
this.abase = 1;
this.running = true;
this.exited = false;
}
runtimeError(msg : string) {
this.curpc--; // we did curpc++ before executing statement
// TODO: pass source location to error
throw new EmuHalt(`${msg} (line ${this.getLabelForPC(this.curpc)})`);
}
// TODO: sometimes on next line
getLineForPC(pc:number) {
var line;
do {
line = this.pc2line.get(pc);
if (line != null) break;
} while (--pc >= 0);
return line;
}
getLabelForPC(pc:number) {
var lineno = this.getLineForPC(pc);
var pgmline = this.program.lines[lineno];
return pgmline ? pgmline.label : '?';
}
getStatement() {
return this.allstmts[this.curpc];
}
step() : boolean {
if (!this.running) return false;
var stmt = this.getStatement();
// end of program?
if (!stmt) {
this.running = false;
this.exited = true;
return false;
}
if (this.trace) console.log(this.curpc, stmt, this.vars, Object.keys(this.arrays));
// skip to next statment
this.curpc++;
// compile statement to JS?
this.compileStatement(stmt);
this.executeStatement(stmt);
return this.running;
}
compileStatement(stmt: basic.Statement & CompiledStatement) {
if (stmt.$run == null) {
var stmtfn = this['do__' + stmt.command];
if (stmtfn == null) this.runtimeError(`I don't know how to "${stmt.command}".`);
var functext = stmtfn.bind(this)(stmt);
if (this.trace) console.log(functext);
stmt.$run = new Function(functext).bind(this);
}
}
executeStatement(stmt: basic.Statement & CompiledStatement) {
// run compiled statement
stmt.$run();
}
skipToEOL() {
do {
this.curpc++;
} while (this.curpc < this.allstmts.length && !this.pc2line.get(this.curpc));
}
skipToEOF() {
this.curpc = this.allstmts.length;
}
gotoLabel(label) {
var pc = this.label2pc[label];
if (pc >= 0) {
this.curpc = pc;
} else {
this.runtimeError(`I tried to go to the label "${label}" but couldn't find it.`);
}
}
gosubLabel(label) {
this.returnStack.push(this.curpc + 1);
this.gotoLabel(label);
}
returnFromGosub() {
if (this.returnStack.length == 0)
this.runtimeError("I tried to RETURN, but there wasn't a corresponding GOSUB."); // RETURN BEFORE GOSUB
var pc = this.returnStack.pop();
this.curpc = pc;
}
valueToString(obj) : string {
var str;
if (typeof obj === 'number') {
var numstr = obj.toString().toUpperCase();
var prec = 11;
while (numstr.length > 11) {
numstr = obj.toPrecision(prec--);
}
if (numstr.startsWith('0.'))
numstr = numstr.substr(1);
else if (numstr.startsWith('-0.'))
numstr = '-'+numstr.substr(2);
if (numstr.startsWith('-')) {
str = `${numstr} `;
} else {
str = ` ${numstr} `;
}
} else if (obj == '\n') {
this.column = 0;
str = obj;
} else if (obj == '\t') {
var curgroup = Math.floor(this.column / 15);
var nextcol = (curgroup + 1) * 15;
str = this.TAB(nextcol);
} else {
str = `${obj}`;
}
return str;
}
printExpr(obj) {
var str = this.valueToString(obj);
this.column += str.length;
this.print(str);
}
// override this
print(str: string) {
console.log(str);
}
// override this
async input(prompt: string, nargs: number) : Promise<string[]> {
return [];
}
// override this
resume() { }
expr2js(expr: basic.Expr, opts: ExprOptions) : string {
if (isLiteral(expr)) {
return JSON.stringify(expr.value);
} else if (isLookup(expr)) {
if (opts.locals && opts.locals.indexOf(expr.name) >= 0) {
return expr.name; // local arg in DEF
} else {
if (opts.isconst) this.runtimeError(`I expected a constant value here`);
var s = '';
if (expr.args && this[expr.name]) { // is it a function?
s += `this.${expr.name}(`;
s += expr.args.map((arg) => this.expr2js(arg, opts)).join(', ');
s += ')';
} else if (expr.args) { // is it a subscript?
s += `this.getArray(${JSON.stringify(expr.name)}, ${expr.args.length})`;
s += expr.args.map((arg) => '[this.ROUND('+this.expr2js(arg, opts)+')]').join('');
} else {
// just a variable
s = `this.vars.${expr.name}`;
}
if (opts.check)
return `this.checkValue(${s}, ${JSON.stringify(expr.name)})`; // TODO: better error
else
return s;
}
} else if (isBinOp(expr)) {
var left = this.expr2js(expr.left, opts);
var right = this.expr2js(expr.right, opts);
return `this.${expr.op}(${left}, ${right})`;
} else if (isUnOp(expr) && expr.op == 'neg') {
var e = this.expr2js(expr.expr, opts);
return `-(${e})`; // TODO: other ops?
}
}
startForLoop(name, init, targ, step) {
// TODO: check for loop params
var pc = this.curpc;
if (!step) step = 1;
this.vars[name] = init;
if (this.trace) console.log(`FOR ${name} = ${this.vars[name]} TO ${targ} STEP ${step}`);
this.forLoops[name] = {
next: () => {
var done = step >= 0 ? this.vars[name] >= targ : this.vars[name] <= targ;
if (done) {
delete this.forLoops[name];
} else {
this.vars[name] += step;
this.curpc = pc;
}
if (this.trace) console.log(`NEXT ${name}: ${this.vars[name]} TO ${targ} STEP ${step} DONE=${done}`);
}
};
}
nextForLoop(name) {
// TODO: check for for loop
var fl = this.forLoops[name];
if (!fl) this.runtimeError(`I couldn't find a matching FOR for this NEXT.`)
this.forLoops[name].next();
}
// converts a variable to string/number based on var name
convert(name: string, right: number|string) : number|string {
// TODO: error check?
if (name.endsWith("$"))
return right+"";
else if (typeof right === 'string')
return parseFloat(right);
else if (typeof right === 'number')
return right;
else
return this.checkValue(right, name);
}
// dimension array
dimArray(name: string, ...dims:number[]) {
var isstring = name.endsWith('$');
// TODO: option for undefined float array elements?
var arrcons = isstring ? Array : Float64Array;
var ab = this.abase;
if (dims.length == 1) {
this.arrays[name] = new arrcons(dims[0]+ab);
} else if (dims.length == 2) {
this.arrays[name] = new Array(dims[0]+ab);
for (var i=ab; i<dims[0]+ab; i++)
this.arrays[name][i] = new arrcons(dims[1]+ab);
} else {
this.runtimeError(`I only support arrays of one or two dimensions.`)
}
}
getArray(name: string, order: number) : [] {
if (!this.arrays[name]) {
if (order == 1)
this.dimArray(name, 11);
else if (order == 2)
this.dimArray(name, 11, 11);
else
this.runtimeError(`I only support arrays of one or two dimensions.`)
}
return this.arrays[name];
}
onGotoLabel(value: number, ...labels: string[]) {
value = this.ROUND(value);
if (value < 1 || value > labels.length)
this.runtimeError(`I needed a number between 1 and ${labels.length}, but I got ${value}.`);
this.gotoLabel(labels[value-1]);
}
nextDatum() : string|number {
if (this.dataptr >= this.datums.length)
this.runtimeError("I tried to READ, but ran out of data.");
return this.datums[this.dataptr++].value;
}
//// STATEMENTS
do__PRINT(stmt : basic.PRINT_Statement) {
var s = '';
for (var arg of stmt.args) {
var expr = this.expr2js(arg, {check:true});
s += `this.printExpr(${expr});`;
}
return s;
}
do__INPUT(stmt : basic.INPUT_Statement) {
var prompt = this.expr2js(stmt.prompt, {check:true});
var setvals = '';
stmt.args.forEach((arg, index) => {
var lexpr = this.expr2js(arg, {check:false});
setvals += `${lexpr} = this.convert(${JSON.stringify(arg.name)}, vals[${index}]);`
});
return `this.running=false; this.input(${prompt}, ${stmt.args.length}).then((vals) => {${setvals}; this.running=true; this.resume();})`;
}
do__LET(stmt : basic.LET_Statement) {
var lexpr = this.expr2js(stmt.lexpr, {check:false});
var right = this.expr2js(stmt.right, {check:true});
return `${lexpr} = this.convert(${JSON.stringify(stmt.lexpr.name)}, ${right});`;
}
do__FOR(stmt : basic.FOR_Statement) {
var name = JSON.stringify(stmt.lexpr.name); // TODO: args?
var init = this.expr2js(stmt.initial, {check:true});
var targ = this.expr2js(stmt.target, {check:true});
var step = stmt.step ? this.expr2js(stmt.step, {check:true}) : 'null';
return `this.startForLoop(${name}, ${init}, ${targ}, ${step})`;
}
do__NEXT(stmt : basic.NEXT_Statement) {
var name = JSON.stringify(stmt.lexpr.name); // TODO: args? lexpr == null?
return `this.nextForLoop(${name})`;
}
do__IF(stmt : basic.IF_Statement) {
var cond = this.expr2js(stmt.cond, {check:true});
return `if (!(${cond})) { this.skipToEOL(); }`
}
do__DEF(stmt : basic.DEF_Statement) {
var lexpr = `this.${stmt.lexpr.name}`;
var args = [];
for (var arg of stmt.lexpr.args) {
if (isLookup(arg)) {
args.push(arg.name);
} else {
this.runtimeError("I found a DEF statement with arguments other than variable names.");
}
}
var functext = this.expr2js(stmt.def, {check:true, locals:args});
// TODO: use stmt.args to add function params
return `${lexpr} = function(${args.join(',')}) { return ${functext}; }`;
}
_DIM(dim : basic.IndOp) {
var argsstr = '';
for (var arg of dim.args) {
// TODO: check for float
argsstr += ', ' + this.expr2js(arg, {check:true});
}
return `this.dimArray(${JSON.stringify(dim.name)}${argsstr});`;
}
do__DIM(stmt : basic.DIM_Statement) {
var s = '';
stmt.args.forEach((dim) => s += this._DIM(dim));
return s;
}
do__GOTO(stmt : basic.GOTO_Statement) {
var label = this.expr2js(stmt.label, {check:true});
return `this.gotoLabel(${label})`;
}
do__GOSUB(stmt : basic.GOSUB_Statement) {
var label = this.expr2js(stmt.label, {check:true});
return `this.gosubLabel(${label})`;
}
do__RETURN(stmt : basic.RETURN_Statement) {
return `this.returnFromGosub()`;
}
do__ONGOTO(stmt : basic.ONGOTO_Statement) {
var expr = this.expr2js(stmt.expr, {check:true});
var labels = stmt.labels.map((arg) => this.expr2js(arg, {check:true})).join(', ');
return `this.onGotoLabel(${expr}, ${labels})`;
}
do__DATA() {
// data is preprocessed
}
do__READ(stmt : basic.READ_Statement) {
var s = '';
stmt.args.forEach((arg) => {
s += `${this.expr2js(arg, {check:false})} = this.convert(${JSON.stringify(arg.name)}, this.nextDatum());`;
});
return s;
}
do__RESTORE() {
this.dataptr = 0; // TODO: line number?
}
do__END() {
return `this.skipToEOF()`;
}
do__STOP() {
return `this.skipToEOF()`;
}
do__OPTION(stmt: basic.OPTION_Statement) {
switch (stmt.optname) {
case 'BASE':
let base = parseInt(stmt.optargs[0]);
if (base == 0 || base == 1) this.abase = base;
else this.runtimeError("OPTION BASE can only be 0 or 1.");
break;
default:
this.runtimeError(`OPTION ${stmt.optname} is not supported by this compiler.`);
break;
}
}
// TODO: "SUBSCRIPT ERROR"
// TODO: gosubs nested too deeply
// TODO: memory quota
// FUNCTIONS
checkValue(obj:number|string, exprname:string) {
if (typeof obj !== 'number' && typeof obj !== 'string') {
if (exprname != null && obj == null) {
this.runtimeError(`I didn't find a value for ${exprname}`);
} else if (exprname != null) {
this.runtimeError(`I got an invalid value for ${exprname}: ${obj}`);
} else {
this.runtimeError(`I got an invalid value: ${obj}`);
}
}
return obj;
}
checkNum(n:number) : number {
if (n === Infinity) this.runtimeError(`I computed a number too big to store.`);
if (isNaN(n)) this.runtimeError(`I computed an invalid number.`);
return n;
}
checkString(s:string) : string {
if (typeof s !== 'string') this.runtimeError(`I expected a string here.`);
return s;
}
add(a, b) : number|string {
// TODO: if string-concat
if (typeof a === 'number' && typeof b === 'number')
return this.checkNum(a + b);
else
return a + b;
}
sub(a:number, b:number) : number {
return this.checkNum(a - b);
}
mul(a:number, b:number) : number {
return this.checkNum(a * b);
}
div(a:number, b:number) : number {
if (b == 0) this.runtimeError(`I can't divide by zero.`);
return this.checkNum(a / b);
}
pow(a:number, b:number) : number {
if (a == 0 && b < 0) this.runtimeError(`I can't raise zero to a negative power.`);
return this.checkNum(Math.pow(a, b));
}
land(a:number, b:number) : number {
return a && b;
}
lor(a:number, b:number) : number {
return a || b;
}
eq(a:number, b:number) : boolean {
return a == b;
}
ne(a:number, b:number) : boolean {
return a != b;
}
lt(a:number, b:number) : boolean {
return a < b;
}
gt(a:number, b:number) : boolean {
return a > b;
}
le(a:number, b:number) : boolean {
return a <= b;
}
ge(a:number, b:number) : boolean {
return a >= b;
}
// FUNCTIONS (uppercase)
ABS(arg : number) : number {
return this.checkNum(Math.abs(arg));
}
ASC(arg : string) : number {
return arg.charCodeAt(0);
}
ATN(arg : number) : number {
return this.checkNum(Math.atan(arg));
}
CHR$(arg : number) : string {
return String.fromCharCode(this.checkNum(arg));
}
COS(arg : number) : number {
return this.checkNum(Math.cos(arg));
}
EXP(arg : number) : number {
return this.checkNum(Math.exp(arg));
}
FIX(arg : number) : number {
return this.checkNum(arg - Math.floor(arg));
}
HEX$(arg : number) : string {
return arg.toString(16);
}
INSTR(a, b, c) : number {
if (c != null) {
return this.checkString(c).indexOf(this.checkString(b), a) + 1;
} else {
return this.checkString(b).indexOf(this.checkString(a)) + 1;
}
}
INT(arg : number) : number {
return this.checkNum(Math.floor(arg));
}
LEFT$(arg : string, count : number) : string {
return arg.substr(0, count);
}
LEN(arg : string) : number {
return arg.length;
}
LOG(arg : number) : number {
if (arg == 0) this.runtimeError(`I can't take the logarithm of zero (${arg}).`)
if (arg < 0) this.runtimeError(`I can't take the logarithm of a negative number (${arg}).`)
return this.checkNum(Math.log(arg));
}
MID$(arg : string, start : number, count : number) : string {
if (start < 1) this.runtimeError(`The second parameter to MID$ must be between 1 and the length of the string in the first parameter.`)
return arg.substr(start-1, count);
}
RIGHT$(arg : string, count : number) : string {
return arg.substr(arg.length - count, count);
}
RND(arg : number) : number {
return Math.random(); // argument ignored
}
ROUND(arg : number) : number {
return this.checkNum(Math.round(arg)); // TODO?
}
SGN(arg : number) : number {
return (arg < 0) ? -1 : (arg > 0) ? 1 : 0;
}
SIN(arg : number) : number {
return this.checkNum(Math.sin(arg));
}
SPACE$(arg : number) : string {
return ' '.repeat(this.checkNum(arg));
}
SQR(arg : number) : number {
if (arg < 0) this.runtimeError(`I can't take the square root of a negative number (${arg}).`)
return this.checkNum(Math.sqrt(arg));
}
STR$(arg) : string {
return this.valueToString(arg);
}
TAB(arg : number) : string {
if (arg < 0) this.runtimeError(`I got a negative value for the TAB() function.`);
var spaces = this.ROUND(arg) - this.column;
return (spaces > 0) ? ' '.repeat(spaces) : '';
}
TAN(arg : number) : number {
return this.checkNum(Math.tan(arg));
}
VAL(arg) : number {
return parseFloat(arg+"");
}
}