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jsbasic/basic.js
Joshua Bell 92df9eb56d Missing semicolons
2018-08-01 18:43:57 -07:00

2378 lines
76 KiB
JavaScript
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//
// BASIC Compiler and Executor
//
// API:
// var program = basic.compile(source);
// // may throw basic.ParseError
//
// program.init({tty: ..., hires: .e.., lores: ...})
//
// // if TTY input is blocking:
//
// var state;
// do {
// state = program.step();
// // may throw basic.RuntimeError
// } while (state !== basic.STATE_STOPPED);
//
// // if TTY input is non-blocking:
// function driver() {
// var state;
// do {
// state = program.step(driver);
// // may throw basic.RuntimeError
// } while (state === basic.STATE_RUNNING);
// }
// driver(); // step until done or blocked
// // driver will also be called after input is unblocked
// // driver may want to yield via setTimeout() after N steps
this.basic = (function() {
var basic = {
STATE_STOPPED: 0,
STATE_RUNNING: 1,
STATE_BLOCKED: 2
};
//
// Thrown if parsing fails
//
basic.ParseError = function(msg, line, column) {
this.name = 'ParseError';
this.message = msg || '';
this.line = line;
this.column = column;
};
basic.ParseError.prototype = new Error();
//
// Thrown when a program is running; can be caught by ONERR
//
basic.RuntimeError = function(msg, code) {
this.name = 'RuntimeError';
this.message = msg;
this.code = code;
};
basic.RuntimeError.prototype = new Error();
function runtime_error(msg) {
if (typeof msg === 'object' && msg.length && msg.length >= 2) {
throw new basic.RuntimeError(msg[1], msg[0]);
} else {
throw new basic.RuntimeError(msg);
}
}
var ERRORS = {
NEXT_WITHOUT_FOR: [0, "Next without for"],
SYNTAX_ERROR: [16, "Syntax error"],
RETURN_WITHOUT_GOSUB: [22, "Return without gosub"],
OUT_OF_DATA: [42, "Out of data"],
ILLEGAL_QUANTITY: [53, "Illegal quantity"],
OVERFLOW: [69, "Overflow"],
OUT_OF_MEMORY: [77, "Out of memory"],
UNDEFINED_STATEMENT: [90, "Undefined statement"],
BAD_SUBSCRIPT: [107, "Bad subscript"],
REDIMED_ARRAY: [120, "Redimensioned array"],
DIVISION_BY_ZERO: [133, "Division by zero"],
TYPE_MISMATCH: [163, "Type mismatch"],
STRING_TOO_LONG: [176, "String too long"],
FORMULA_TOO_COMPLEX: [191, "Formula too complex"],
UNDEFINED_FUNCTION: [224, "Undefined function"],
REENTER: [254, "Re-enter"],
INTERRUPT: [255, "Break"]
};
// Keyword table - these can be altered (e.g. localized) here
var kws = {
ABS: "ABS",
AND: "AND",
ASC: "ASC",
ATN: "ATN",
AT: "AT",
CALL: "CALL",
CHR$: "CHR$",
CLEAR: "CLEAR",
COLOR: "COLOR=",
CONT: "CONT",
COS: "COS",
DATA: "DATA",
DEF: "DEF",
DEL: "DEL",
DIM: "DIM",
DRAW: "DRAW",
END: "END",
EXP: "EXP",
FLASH: "FLASH",
FN: "FN",
FOR: "FOR",
FRE: "FRE",
GET: "GET",
GOSUB: "GOSUB",
GOTO: "GOTO",
GR: "GR",
HCOLOR: "HCOLOR=",
HGR2: "HGR2",
HGR: "HGR",
HIMEM: "HIMEM:",
HLIN: "HLIN",
HOME: "HOME",
HPLOT: "HPLOT",
HTAB: "HTAB",
IF: "IF",
IN: "IN#",
INPUT: "INPUT",
INT: "INT",
INVERSE: "INVERSE",
LEFT$: "LEFT$",
LEN: "LEN",
LET: "LET",
LIST: "LIST",
LOAD: "LOAD",
LOG: "LOG",
LOMEM: "LOMEM:",
MID$: "MID$",
NEW: "NEW",
NEXT: "NEXT",
NORMAL: "NORMAL",
NOTRACE: "NOTRACE",
NOT: "NOT",
ONERR: "ONERR",
ON: "ON",
OR: "OR",
PDL: "PDL",
PEEK: "PEEK",
PLOT: "PLOT",
POKE: "POKE",
POP: "POP",
POS: "POS",
PRINT: "PRINT",
PR: "PR#",
READ: "READ",
RECALL: "RECALL",
REM: "REM",
RESTORE: "RESTORE",
RESUME: "RESUME",
RETURN: "RETURN",
RIGHT$: "RIGHT$",
RND: "RND",
ROT: "ROT=",
RUN: "RUN",
SAVE: "SAVE",
SCALE: "SCALE=",
SCRN: "SCRN",
SGN: "SGN",
SHLOAD: "SHLOAD",
SIN: "SIN",
SPC: "SPC",
SPEED: "SPEED=",
SQR: "SQR",
STEP: "STEP",
STOP: "STOP",
STORE: "STORE",
STR$: "STR$",
TAB: "TAB",
TAN: "TAN",
TEXT: "TEXT",
THEN: "THEN",
TO: "TO",
TRACE: "TRACE",
USR: "USR",
VAL: "VAL",
VLIN: "VLIN",
VTAB: "VTAB",
WAIT: "WAIT",
XDRAW: "XDRAW",
AMPERSAND: "&",
QUESTION: "?",
HSCRN: "HSCRN"
};
//
// Runtime flow control
//
function EndProgram() { }
function GoToLine(n) { this.line = n; }
function NextLine() { }
function BlockingInput(method, callback) {
this.method = method;
this.callback = callback;
}
// Adapted from:
// http://stackoverflow.com/questions/424292/how-to-create-my-own-javascript-random-number-generator-that-i-can-also-set-the-s
function PRNG() {
var S = 2345678901, // seed
A = 48271, // const
M = 2147483647, // const
Q = M / A, // const
R = M % A; // const
this.next = function PRNG_next() {
var hi = S / Q,
lo = S % Q,
t = A * lo - R * hi;
S = (t > 0) ? t : t + M;
this.last = S / M;
return this.last;
};
this.seed = function PRNG_seed(x) {
S = Math.floor(Math.abs(x));
};
this.next();
}
// Multidimensional array, with auto-dimensioning on first access
function BASICArray(type, dims) {
var array, dimensions;
function offset(dims, subscripts) {
if (subscripts.length !== dimensions.length) {
runtime_error(ERRORS.BAD_SUBSCRIPT);
}
var k, l, s = 0, p, ss;
for (k = 0; k < dims.length; k += 1) {
ss = subscripts[k];
if (ss < 0) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
ss = ss >> 0;
if (ss >= dims[k]) {
runtime_error(ERRORS.BAD_SUBSCRIPT);
}
p = 1;
for (l = k + 1; l < dims.length; l += 1) {
p *= dims[l];
}
s += p * ss;
}
return s;
}
this.dim = function dim(dims) {
if (array) {
runtime_error(ERRORS.REDIMED_ARRAY);
}
dimensions = dims.map(function(n) { return (Number(n) >> 0) + 1; });
var i, len = dimensions.reduce(function(a, b) { return a * b; }),
defval = (type === 'string') ? '' : 0;
array = [];
for (i = 0; i < len; i += 1) {
array[i] = defval;
}
};
this.get = function get(subscripts) {
if (!array) {
this.dim(subscripts.map(function() { return 10; }));
}
return array[offset(dimensions, subscripts)];
};
this.set = function set(subscripts, value) {
if (!array) {
this.dim(subscripts.map(function() { return 10; }));
}
array[offset(dimensions, subscripts)] = value;
};
this.toJSON = function toJSON() {
return { type: type, dimensions: dimensions, array: array };
};
if (dims) {
this.dim(dims);
}
}
// Stream API, for parsing source and INPUT entry
function Stream(string) {
this.line = 0;
this.column = 0;
this.match = function match(re) {
var m = string.match(re), lines;
if (m) {
string = string.substring(m[0].length);
lines = m[0].split('\n');
if (lines.length > 1) {
this.line += lines.length - 1;
this.column = lines[lines.length - 1].length;
} else {
this.column += m[0].length;
}
this.lastMatch = m;
return m;
}
return (void 0);
};
this.eof = function eof() {
return string.length === 0;
};
}
// Used for DATA (compile-time) and INPUT (runtime)
// Parses source string for optionally quoted, comma-
// separated values and adds them to items. Returns
// the substring consumed.
var parseDataInput = (function() {
var regexWhitespace = /^[ \t]+/,
regexQuotedString = /^"([^"]*?)"/,
regexUnquotedString = /^[^:,\r\n]*/,
regexComma = /^,/;
return function parseDataInput(stream, items) {
do {
stream.match(regexWhitespace);
if (stream.match(regexQuotedString)) {
// quoted string
items.push(stream.lastMatch[1]);
} else if (stream.match(regexUnquotedString)) {
// unquoted string
items.push(stream.lastMatch[0]);
}
} while (stream.match(regexComma));
};
} ());
basic.compile = function compile(source) {
"use strict";
function vartype(name) {
var s = name.charAt(name.length - 1);
return s === '$' ? 'string' : s === '%' ? 'int' : 'float';
}
//----------------------------------------------------------------------
//
// Runtime Environment (bound to compiled program)
//
//----------------------------------------------------------------------
var env, // Environment - passed in to program, contains tty, graphics, etc.
state, // Program state - initialized at runtime
lib, // Statement Library (closure over state and env)
funlib, // Function Library (closure over state and env)
peek_table, // Native memory access shims (PEEK, POKE, CALL)
poke_table,
call_table;
//
// NOTE: tempting to make these part of env but some access/modify program state,
// e.g. onerr
//
peek_table = {
// Text window
0x0020: function() { return env.tty.textWindow ? env.tty.textWindow.left : 0; },
0x0021: function() { return env.tty.textWindow ? env.tty.textWindow.width : 80; },
0x0022: function() { return env.tty.textWindow ? env.tty.textWindow.top : 0; },
0x0023: function() { return env.tty.textWindow ? env.tty.textWindow.top + env.tty.textWindow.height : 24; },
0x0024: function() { return env.tty.getCursorPosition().x; },
0x0025: function() { return env.tty.getCursorPosition().y; },
// Random number field
0x004e: function() { return (Math.random() * 256) & 0xff; },
0x004f: function() { return (Math.random() * 256) & 0xff; },
// Last error code
0x00de: function() { return state.onerr_code; },
// Hires Plotting Page (32=1, 64=2, 96=3)
0x00e6: function() { return env.display ? (env.display.hires_plotting_page === 2 ? 64 : 32) : 0; },
// TODO: 0x3D0 = 0x4C if DOS is present.
// Keyboard
0xC000: function() { return env.tty.getKeyboardRegister ? env.tty.getKeyboardRegister() : 0; },
0xC010: function() { return env.tty.clearKeyboardStrobe ? env.tty.clearKeyboardStrobe() : 0; },
// Speaker toggle
0xC030: function() { return 0; },
// Buttons
0xC060: function() { return env.tty.getButtonState ? env.tty.getButtonState(3) : 0; },
0xC061: function() { return env.tty.getButtonState ? env.tty.getButtonState(0) : 0; },
0xC062: function() { return env.tty.getButtonState ? env.tty.getButtonState(1) : 0; },
0xC063: function() { return env.tty.getButtonState ? env.tty.getButtonState(2) : 0; }
};
poke_table = {
// Text window
0x0020: function(v) { if (env.tty.textWindow) { env.tty.textWindow.left = v; } },
0x0021: function(v) { if (env.tty.textWindow) { env.tty.textWindow.width = v; } },
0x0022: function(v) { if (env.tty.textWindow) { env.tty.textWindow.top = v; } },
0x0023: function(v) { if (env.tty.textWindow) { env.tty.textWindow.height = v - env.tty.textWindow.top; } },
0x0024: function(v) { env.tty.setCursorPosition(v, void 0); },
0x0025: function(v) { env.tty.setCursorPosition(void 0, v); },
// ONERR flag
0x00D8: function(v) { if (v < 0x80) { state.onerr_handler = (void 0); } },
// Hires Plotting Page (32=1, 64=2, 96=3)
0x00E6: function(v) { if (env.display) { env.display.hires_plotting_page = (v === 64 ? 2 : 1); } },
// Keyboard strobe
0xC010: function() { if (env.tty.clearKeyboardStrobe) { env.tty.clearKeyboardStrobe(); } },
// Display switches
0xC050: function() { if (env.display) { env.display.setState("graphics", true); } }, // Graphics
0xC051: function() { if (env.display) { env.display.setState("graphics", false); } }, // Text
0xC052: function() { if (env.display) { env.display.setState("full", true); } }, // Full Graphics
0xC053: function() { if (env.display) { env.display.setState("full", false); } }, // Split Screen
0xC054: function() { if (env.display) { env.display.setState("page1", true); } }, // Page 1
0xC055: function() { if (env.display) { env.display.setState("page1", false); } }, // Page 2
0xC056: function() { if (env.display) { env.display.setState("lores", true); } }, // Lo-Res
0xC057: function() { if (env.display) { env.display.setState("lores", false); } }, // Hi-Res
// Speaker toggle
0xC030: function() { } // no-op
};
call_table = {
0xD683: function() { // Clear stack
state.stack = [];
},
0xF328: function() { // Pop error entry off stack
var stack_record = state.stack.pop();
if (!{}.hasOwnProperty.call(stack_record, 'resume_stmt_index')) {
runtime_error(ERRORS.SYNTAX_ERROR);
return;
}
},
0xF3E4: function() { // Reveal hi-res page 1
if (!env.hires) { runtime_error('Hires graphics not supported'); }
env.display.setState('graphics', true, 'full', true, 'page1', true, 'lores', false);
},
0xF3F2: function() { // Clear hi-res screen to black
var hires = env.display.hires_plotting_page === 2 ? env.hires2 : env.hires;
if (!hires) { runtime_error('Hires graphics not supported'); }
hires.clear();
},
0xF3F6: function() { // Clear hi-res screen to last color Hplotted
var hires = env.display.hires_plotting_page === 2 ? env.hires2 : env.hires;
if (!hires) { runtime_error('Hires graphics not supported'); }
hires.clear(hires.color);
},
0xFBF4: function() { // Move cursor right
if (env.tty.cursorRight) { env.tty.cursorRight(); }
},
0xFC10: function() { // Move cursor left
if (env.tty.cursorLeft) { env.tty.cursorLeft(); }
},
0xFC1A: function() { // Move cursor up
if (env.tty.cursorUp) { env.tty.cursorUp(); }
},
0xFC42: function() { // Clear text from cursor to bottom
if (env.tty.clearEOS) { env.tty.clearEOS(); }
},
0xFC66: function() { // Move cursor down
if (env.tty.cursorDown) { env.tty.cursorDown(); }
},
0xFC9C: function() { // Clear from cursor to right
if (env.tty.clearEOL) { env.tty.clearEOL(); }
},
0xFD0C: function() { // Wait for key press
throw new BlockingInput(env.tty.readChar, function(_){});
},
0xFE84: function() { // Normal
if (env.tty.setTextStyle) { env.tty.setTextStyle(env.tty.TEXT_STYLE_NORMAL); }
},
0xFE80: function() { // Inverse
if (env.tty.setTextStyle) { env.tty.setTextStyle(env.tty.TEXT_STYLE_INVERSE); }
}
};
lib = {
//////////////////////////////////////////////////////////////////////
//
// Variable Statements
//
//////////////////////////////////////////////////////////////////////
'clear': function CLEAR() {
state.clear();
},
'dim': function DIM(name, subscripts) {
state.arrays[name].dim(subscripts);
},
'def': function DEF(name, func) {
state.functions[name] = func;
},
//////////////////////////////////////////////////////////////////////
//
// Flow Control Statements
//
//////////////////////////////////////////////////////////////////////
'goto': function GOTO(line) {
throw new GoToLine(line);
},
'on_goto': function ON_GOTO(index /* , ...lines */) {
index = Math.floor(index);
if (index < 0 || index > 255) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
--index;
var lines = Array.prototype.slice.call(arguments, 1);
if (index >= 0 && index < lines.length) {
throw new GoToLine(lines[index]);
}
},
'gosub': function GOSUB(line) {
state.stack.push({
gosub_return: state.stmt_index,
line_number: state.line_number
});
throw new GoToLine(line);
},
'on_gosub': function ON_GOSUB(index /* , ...lines */) {
index = Math.floor(index);
if (index < 0 || index > 255) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
--index;
var lines = Array.prototype.slice.call(arguments, 1);
if (index >= 0 && index < lines.length) {
state.stack.push({
gosub_return: state.stmt_index,
line_number: state.line_number
});
throw new GoToLine(lines[index]);
}
},
'return': function RETURN() {
var stack_record;
while (state.stack.length) {
stack_record = state.stack.pop();
if ({}.hasOwnProperty.call(stack_record, 'gosub_return')) {
state.stmt_index = stack_record.gosub_return;
state.line_number = stack_record.line_number;
return;
}
}
runtime_error(ERRORS.RETURN_WITHOUT_GOSUB);
},
'pop': function POP() {
var stack_record = state.stack.pop();
if (!{}.hasOwnProperty.call(stack_record, 'gosub_return')) {
runtime_error(ERRORS.RETURN_WITHOUT_GOSUB);
return;
}
},
'for': function FOR(varname, from, to, step) {
state.variables[varname] = from;
state.stack.push({
index: varname,
from: from,
to: to,
step: step,
for_next: state.stmt_index,
line_number: state.line_number
});
},
'next': function NEXT(/* ...varnames */) {
var varnames = Array.prototype.slice.call(arguments),
varname, stack_record, value;
do {
varname = varnames.shift();
do {
stack_record = state.stack.pop();
if (!stack_record || !{}.hasOwnProperty.call(stack_record, 'for_next')) {
runtime_error(ERRORS.NEXT_WITHOUT_FOR);
}
} while (varname !== (void 0) && stack_record.index !== varname);
value = state.variables[stack_record.index];
value = value + stack_record.step;
state.variables[stack_record.index] = value;
if (!(stack_record.step > 0 && value > stack_record.to) &&
!(stack_record.step < 0 && value < stack_record.to) &&
!(stack_record.step === 0 && value === stack_record.to)) {
state.stack.push(stack_record);
state.stmt_index = stack_record.for_next;
state.line_number = stack_record.line_number;
return;
}
} while (varnames.length);
},
'if': function IF(value) {
if (!value) {
throw new NextLine();
}
},
'stop': function STOP() {
runtime_error(ERRORS.INTERRUPT);
},
'end': function END() {
throw new EndProgram();
},
//////////////////////////////////////////////////////////////////////
//
// Error Handling Statements
//
//////////////////////////////////////////////////////////////////////
'onerr_goto': function ONERR_GOTO(line) {
state.onerr_handler = line;
throw new NextLine();
},
'resume': function RESUME() {
var stack_record = state.stack.pop();
if (!{}.hasOwnProperty.call(stack_record, 'resume_stmt_index')) {
runtime_error(ERRORS.SYNTAX_ERROR);
return;
}
state.line_number = stack_record.resume_line_number;
state.stmt_index = stack_record.resume_stmt_index;
},
//////////////////////////////////////////////////////////////////////
//
// Inline Data Statements
//
//////////////////////////////////////////////////////////////////////
'restore': function RESTORE() {
state.data_index = 0;
},
// PERF: optimize by turning into a function, e.g. "state.parsevar(name, lib.read())"
'read': function READ(/* ...lvalues */) {
var lvalues = Array.prototype.slice.call(arguments);
while (lvalues.length) {
if (state.data_index >= state.data.length) {
runtime_error(ERRORS.OUT_OF_DATA);
}
(lvalues.shift())(state.data[state.data_index]);
state.data_index += 1;
}
},
//////////////////////////////////////////////////////////////////////
//
// I/O Statements
//
//////////////////////////////////////////////////////////////////////
'print': function PRINT(/* ...strings */) {
var args = Array.prototype.slice.call(arguments), arg;
while (args.length) {
arg = args.shift();
if (typeof arg === 'function') {
arg = arg();
}
env.tty.writeString(String(arg));
}
},
'comma': function COMMA() {
return function() {
var cur = env.tty.getCursorPosition().x,
pos = (cur + 16) - (cur % 16);
if (pos >= env.tty.getScreenSize().width) {
return '\r';
} else {
return ' '.repeat(pos - cur);
}
};
},
'spc': function SPC(n) {
n = n >> 0;
if (n < 0 || n > 255) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
return function() {
return ' '.repeat(n);
};
},
'tab': function TAB(n) {
n = n >> 0;
if (n < 0 || n > 255) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
if (n === 0) { n = 256; }
return function() {
var pos = env.tty.getCursorPosition().x + 1;
return ' '.repeat(pos >= n ? 0 : n - pos);
};
},
'get': function GET(lvalue) {
throw new BlockingInput(env.tty.readChar, function(entry) { lvalue(entry); });
},
'input': function INPUT(prompt /* , ...varlist */) {
var varlist = Array.prototype.slice.call(arguments, 1); // copy for closure
var im = function(cb) { return env.tty.readLine(cb, prompt); };
var ih = function(entry) {
var parts = [],
stream = new Stream(entry);
parseDataInput(stream, parts);
while (varlist.length && parts.length) {
try {
varlist.shift()(parts.shift());
} catch (e) {
if (e instanceof basic.RuntimeError &&
e.code === ERRORS.TYPE_MISMATCH[0]) {
e.code = ERRORS.REENTER[0];
e.message = ERRORS.REENTER[1];
}
throw e;
}
}
if (varlist.length) {
prompt = '??';
throw new BlockingInput(im, ih);
}
if (parts.length) {
env.tty.writeString('?EXTRA IGNORED\r');
}
};
throw new BlockingInput(im, ih);
},
'home': function HOME() {
if (env.tty.clearScreen) { env.tty.clearScreen(); }
},
'htab': function HTAB(pos) {
if (pos < 1 || pos >= env.tty.getScreenSize().width + 1) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
if (env.tty.textWindow) {
pos += env.tty.textWindow.left;
}
env.tty.setCursorPosition(pos - 1, void 0);
},
'vtab': function VTAB(pos) {
if (pos < 1 || pos >= env.tty.getScreenSize().height + 1) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
env.tty.setCursorPosition(void 0, pos - 1);
},
'inverse': function INVERSE() {
if (env.tty.setTextStyle) { env.tty.setTextStyle(env.tty.TEXT_STYLE_INVERSE); }
},
'flash': function FLASH() {
if (env.tty.setTextStyle) { env.tty.setTextStyle(env.tty.TEXT_STYLE_FLASH); }
},
'normal': function NORMAL() {
if (env.tty.setTextStyle) { env.tty.setTextStyle(env.tty.TEXT_STYLE_NORMAL); }
},
'text': function TEXT() {
if (env.display) {
env.display.setState("graphics", false);
}
if (env.tty.textWindow) {
// Reset text window
env.tty.textWindow = {
left: 0,
top: 0,
width: env.tty.getScreenSize().width,
height: env.tty.getScreenSize().height
};
}
},
//////////////////////////////////////////////////////////////////////
//
// Miscellaneous Statements
//
//////////////////////////////////////////////////////////////////////
'notrace': function NOTRACE() {
state.trace_mode = false;
},
'trace': function TRACE() {
state.trace_mode = true;
},
//////////////////////////////////////////////////////////////////////
//
// Lores Graphics
//
//////////////////////////////////////////////////////////////////////
'gr': function GR() {
if (!env.lores) { runtime_error('Lores graphics not supported'); }
env.display.setState("lores", true, "full", false, "graphics", true);
env.lores.clear();
env.tty.setCursorPosition(0, env.tty.getScreenSize().height);
},
'color': function COLOR(n) {
if (!env.lores) { runtime_error('Lores graphics not supported'); }
n = n >> 0;
if (n < 0) { runtime_error(ERRORS.ILLEGAL_QUANTITY); }
env.lores.setColor(n);
},
'plot': function PLOT(x, y) {
if (!env.lores) { runtime_error('Lores graphics not supported'); }
x = x >> 0;
y = y >> 0;
var size = env.lores.getScreenSize();
if (x < 0 || y < 0 || x >= size.width || y >= size.height) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
env.lores.plot(x, y);
},
'hlin': function HLIN(x1, x2, y) {
if (!env.lores) { runtime_error('Lores graphics not supported'); }
x1 = x1 >> 0;
x2 = x2 >> 0;
y = y >> 0;
var size = env.lores.getScreenSize();
if (x1 < 0 || x2 < 0 || y < 0 ||
x1 >= size.width || x2 >= size.width || y >= size.height) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
env.lores.hlin(x1, x2, y);
},
'vlin': function VLIN(y1, y2, x) {
if (!env.lores) { runtime_error('Lores graphics not supported'); }
y1 = y1 >> 0;
y2 = y2 >> 0;
x = x >> 0;
var size = env.lores.getScreenSize();
if (x < 0 || y1 < 0 || y2 < 0 ||
x >= size.width || y1 >= size.height || y2 >= size.height) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
env.lores.vlin(y1, y2, x);
},
//////////////////////////////////////////////////////////////////////
//
// Hires Graphics
//
//////////////////////////////////////////////////////////////////////
'hgr': function HGR() {
if (!env.hires) { runtime_error('Hires graphics not supported'); }
env.display.setState("lores", false, "full", false, "page1", true, "graphics", true);
env.display.hires_plotting_page = 1;
env.hires.clear();
},
'hgr2': function HGR2() {
if (!env.hires) { runtime_error('Hires graphics not supported'); }
env.display.setState("lores", false, "full", true, "page1", false, "graphics", true);
env.display.hires_plotting_page = 2;
env.hires2.clear();
},
'hcolor': function HCOLOR(n) {
if (!env.hires) { runtime_error('Hires graphics not supported'); }
n = n >> 0;
if (n < 0 || n > 7) { runtime_error(ERRORS.ILLEGAL_QUANTITY); }
env.hires.setColor(n);
if (env.hires2) { env.hires2.setColor(n); }
},
'hplot': function HPLOT(/* ...coords */) {
var hires = env.display.hires_plotting_page === 2 ? env.hires2 : env.hires;
if (!hires) { runtime_error('Hires graphics not supported'); }
var coords = Array.prototype.slice.call(arguments),
size = hires.getScreenSize(),
x, y;
x = coords.shift() >> 0;
y = coords.shift() >> 0;
if (x < 0 || y < 0 || x >= size.width || y >= size.height) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
hires.plot(x, y);
while (coords.length) {
x = coords.shift() >> 0;
y = coords.shift() >> 0;
if (x < 0 || y < 0 || x >= size.width || y >= size.height) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
hires.plot_to(x, y);
}
},
'hplot_to': function HPLOT_TO(/* ...coords */) {
var hires = env.display.hires_plotting_page === 2 ? env.hires2 : env.hires;
if (!hires) { runtime_error('Hires graphics not supported'); }
var coords = Array.prototype.slice.call(arguments),
size = hires.getScreenSize(), x, y;
while (coords.length) {
x = coords.shift() >> 0;
y = coords.shift() >> 0;
if (x < 0 || y < 0 || x >= size.width || y >= size.height) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
hires.plot_to(x, y);
}
},
//////////////////////////////////////////////////////////////////////
//
// Compatibility shims
//
//////////////////////////////////////////////////////////////////////
'pr#': function PR(slot) {
if (slot === 0) {
if (env.tty.setFirmwareActive) { env.tty.setFirmwareActive(false); }
} else if (slot === 3) {
if (env.tty.setFirmwareActive) { env.tty.setFirmwareActive(true); }
}
},
'poke': function POKE(address, value) {
address = address & 0xffff;
value = value >> 0;
if (value < 0 || value > 255) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
if (!({}.hasOwnProperty.call(poke_table, address))) {
runtime_error("Unsupported POKE location: " + address);
}
poke_table[address](value);
},
'call': function CALL(address) {
address = address & 0xffff;
if (!({}.hasOwnProperty.call(call_table, address))) {
runtime_error("Unsupported POKE location: " + address);
}
call_table[address]();
},
'speed': function SPEED(n) {
n = n >> 0;
if (n < 0 || n > 255) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
env.tty.speed = n;
},
//////////////////////////////////////////////////////////////////////
//
// Referenced by compiled functions
//
//////////////////////////////////////////////////////////////////////
'div': function div(n, d) {
var r = n / d;
if (!isFinite(r)) { runtime_error(ERRORS.DIVISION_BY_ZERO); }
return r;
},
'fn': function fn(name, arg) {
if (!{}.hasOwnProperty.call(state.functions, name)) {
runtime_error(ERRORS.UNDEFINED_FUNCTION);
}
return state.functions[name](arg);
},
'checkFinite': function checkFinite(n) {
if (!isFinite(n)) { runtime_error(ERRORS.OVERFLOW); }
return n;
},
'toint': function toint(n) {
n = n >> 0;
if (n > 0x7fff || n < -0x8000) { runtime_error(ERRORS.ILLEGAL_QUANTITY); }
return n;
}
};
// Apply a signature [return_type, arg0_type, arg1_type, ...] to a function
function funcsign(func /*, return_type, ...arg_types */) {
func.signature = Array.prototype.slice.call(arguments, 1);
return func;
}
funlib = {};
//////////////////////////////////////////////////////////////////////
//
// Functions
//
// name: [ impl, returntype, [arg0type [, arg1type [, ... ] ]
//
//////////////////////////////////////////////////////////////////////
funlib[kws.ABS] = funcsign(Math.abs, 'number', 'number');
funlib[kws.ASC] = funcsign(function(s) {
if (s.length < 1) { runtime_error(ERRORS.ILLEGAL_QUANTITY); }
return s.charCodeAt(0);
}, 'number', 'string');
funlib[kws.ATN] = funcsign(Math.atan, 'number', 'number');
funlib[kws.CHR$] = funcsign(String.fromCharCode, 'string', 'number');
funlib[kws.COS] = funcsign(Math.cos, 'number', 'number');
funlib[kws.EXP] = funcsign(Math.exp, 'number', 'number');
funlib[kws.INT] = funcsign(Math.floor, 'number', 'number');
funlib[kws.LEN] = funcsign(function LEN(s) { return s.length; }, 'number', 'string');
funlib[kws.LOG] = funcsign(Math.log, 'number', 'number');
funlib[kws.SGN] = funcsign(function SGN(n) { return n > 0 ? 1 : n < 0 ? -1 : 0; }, 'number', 'number');
funlib[kws.SIN] = funcsign(Math.sin, 'number', 'number');
funlib[kws.SQR] = funcsign(Math.sqrt, 'number', 'number');
funlib[kws.STR$] = funcsign(function STR$(n) { return n.toString(); }, 'string', 'number');
funlib[kws.TAN] = funcsign(Math.tan, 'number', 'number');
funlib[kws.VAL] = funcsign(function VAL(s) {
var n = parseFloat(s);
return isFinite(n) ? n : 0;
}, 'number', 'string');
funlib[kws.RND] = funcsign(function RND(n) {
if (n > 0) {
// Next in PRNG sequence
return state.prng.next();
} else if (n < 0) {
// Re-seed. NOTE: Not predictable as in Applesoft
state.prng.seed(n);
return state.prng.next();
}
return state.prng.last;
}, 'number', 'number');
funlib[kws.LEFT$] = funcsign(function LEFT$(s, n) { return s.substring(0, n); }, 'string', 'string', 'number');
funlib[kws.MID$] = funcsign(function MID$(s, n, n2) { return n2 === (void 0) ? s.substring(n - 1) : s.substring(n - 1, n + n2 - 1); }, 'string', 'string', 'number', 'number?');
funlib[kws.RIGHT$] = funcsign(function RIGHT$(s, n) { return s.length < n ? s : s.substring(s.length - n); }, 'string', 'string', 'number');
funlib[kws.POS] = funcsign(function POS(n) { return env.tty.getCursorPosition().x; }, 'number', 'number');
funlib[kws.SCRN] = funcsign(function SCRN(x, y) {
if (!env.lores) { runtime_error("Graphics not supported"); }
x = x >> 0;
y = y >> 0;
var size = env.lores.getScreenSize();
if (x < 0 || y < 0 || x >= size.width || y >= size.height) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
return env.lores.getPixel(x, y);
}, 'number', 'number', 'number');
funlib[kws.HSCRN] = funcsign(function HSCRN(x, y) {
var hires = env.display.hires_plotting_page === 2 ? env.hires2 : env.hires;
if (!hires) { runtime_error("Graphics not supported"); }
x = x >> 0;
y = y >> 0;
var size = hires.getScreenSize();
if (x < 0 || y < 0 || x >= size.width || y >= size.height) {
runtime_error(ERRORS.ILLEGAL_QUANTITY);
}
return hires.getPixel(x, y);
}, 'number', 'number', 'number');
funlib[kws.PDL] = funcsign(function PDL(n) {
if (env.paddle) {
return (env.paddle(n) * 255) & 0xff;
} else {
return runtime_error('Paddles not attached');
}
}, 'number', 'number');
funlib[kws.FRE] = funcsign(function FRE(n) {
return JSON ? JSON.stringify([state.variables, state.arrays, state.functions]).length : 0;
}, 'number', 'number');
funlib[kws.PEEK] = funcsign(function PEEK(address) {
address = address & 0xffff;
if (!{}.hasOwnProperty.call(peek_table, address)) {
runtime_error("Unsupported PEEK location: " + address);
}
return peek_table[address]();
}, 'number', 'number');
// Not supported
funlib[kws.USR] = funcsign(function USR(n) { runtime_error("USR Function not supported"); }, 'number', 'number');
//----------------------------------------------------------------------
//
// Parser / Compiler
//
//----------------------------------------------------------------------
var program = (function() {
var identifiers = {
variables: {},
arrays: {}
};
//////////////////////////////////////////////////////////////////////
//
// Lexical Analysis
//
//////////////////////////////////////////////////////////////////////
var match, test, endOfStatement, endOfProgram,
currLine = 0, currColumn = 0,
currLineNumber = 0;
function parse_error(msg) {
return new basic.ParseError(msg + " in line " + currLineNumber,
currLine, currColumn);
}
(function(source) {
function munge(kw) {
// Escape special characters
function escape(c) { return (/[\[\]\\\^\$\.\|\?\*\+\(\)]/).test(c) ? '\\' + c : c; }
// Allow linear whitespace between characters
//return kw.split('').map(escape).join('[ \\t]*');
// Allow linear whitespace in HCOLOR=, HIMEM:, CHR$, etc
return kw.split(/(?=\W)/).map(escape).join('[ \\t]*');
}
var RESERVED_WORDS = [
kws.ABS, kws.AND, kws.ASC, kws.ATN, kws.AT, kws.CALL,
kws.CHR$, kws.CLEAR, kws.COLOR, kws.CONT, kws.COS,
/*kws.DATA,*/ kws.DEF, kws.DEL, kws.DIM, kws.DRAW, kws.END,
kws.EXP, kws.FLASH, kws.FN, kws.FOR, kws.FRE, kws.GET,
kws.GOSUB, kws.GOTO, kws.GR, kws.HCOLOR, kws.HGR2, kws.HGR,
kws.HIMEM, kws.HLIN, kws.HOME, kws.HPLOT, kws.HTAB, kws.IF,
kws.IN, kws.INPUT, kws.INT, kws.INVERSE, kws.LEFT$, kws.LEN,
kws.LET, kws.LIST, kws.LOAD, kws.LOG, kws.LOMEM, kws.MID$,
kws.NEW, kws.NEXT, kws.NORMAL, kws.NOTRACE, kws.NOT,
kws.ONERR, kws.ON, kws.OR, kws.PDL, kws.PEEK, kws.PLOT,
kws.POKE, kws.POP, kws.POS, kws.PRINT, kws.PR, kws.READ,
kws.RECALL, /*kws.REM,*/ kws.RESTORE, kws.RESUME,
kws.RETURN, kws.RIGHT$, kws.RND, kws.ROT, kws.RUN, kws.SAVE,
kws.SCALE, kws.SCRN, kws.SGN, kws.SHLOAD, kws.SIN, kws.SPC,
kws.SPEED, kws.SQR, kws.STEP, kws.STOP, kws.STORE, kws.STR$,
kws.TAB, kws.TAN, kws.TEXT, kws.THEN, kws.TO, kws.TRACE,
kws.USR, kws.VAL, kws.VLIN, kws.VTAB, kws.WAIT, kws.XDRAW,
kws.AMPERSAND, kws.QUESTION, kws.HSCRN
];
// NOTE: keywords that are stems of other words need to go after (e.g. "NOTRACE", "NOT)
RESERVED_WORDS.sort();
RESERVED_WORDS.reverse();
var regexReservedWords = new RegExp("^(" + RESERVED_WORDS.map(munge).join("|") + ")", "i"),
regexIdentifier = /^([A-Za-z][A-Za-z0-9]?)[A-Za-z0-9]*(\$|%)?/,
regexStringLiteral = /^"([^"]*?)(?:"|(?=\n|\r|$))/,
regexNumberLiteral = /^[0-9]*\.?[0-9]+(?:[eE]\s*[\-+]?\s*[0-9]+)?/,
regexHexLiteral = /^\$[0-9A-Fa-f]+/,
regexOperator = /^[;=<>+\-*\/\^(),]/,
regexLineNumber = /^[0-9]+/,
regexSeparator = /^:/,
regexRemark = new RegExp('^(' + munge(kws.REM) + '([^\r\n]*))', 'i'),
regexData = new RegExp('^(' + munge(kws.DATA) + ')', 'i'),
regexLinearWhitespace = /^[ \t]+/,
regexNewline = /^\r?\n/;
// Token types:
// lineNumber - start of a new line
// separator - separates statements on same line
// reserved - reserved keyword (command, function, etc)
// identifier - variable name
// string - string literal
// number - number literal
// operator - operator
// remark - REM blah
// data - DATA blah,"blah",blah
var start = true,
stream = new Stream(source);
function nextToken() {
var token = {}, newline = start, ws;
start = false;
currLine = stream.line + 1;
currColumn = stream.column + 1;
// Consume whitespace
do {
ws = false;
if (stream.match(regexLinearWhitespace)) {
ws = true;
} else if (stream.match(regexNewline)) {
ws = true;
newline = true;
}
} while (ws);
if (stream.eof()) {
return (void 0);
}
if (newline) {
if (stream.match(regexLineNumber)) {
token.lineNumber = Number(stream.lastMatch[0]);
} else if (stream.match(regexSeparator)) {
// Extension - allow leading : to continue previous line
token.separator = stream.lastMatch[0];
} else {
throw parse_error("Syntax error: Expected line number or separator");
}
} else if (stream.match(regexRemark)) {
token.remark = stream.lastMatch[2];
} else if (stream.match(regexData)) {
token.data = [];
parseDataInput(stream, token.data);
} else if (stream.match(regexReservedWords)) {
token.reserved = stream.lastMatch[1].toUpperCase().replace(/\s+/g, '');
if (token.reserved === kws.QUESTION) { token.reserved = kws.PRINT; } // HACK
} else if (stream.match(regexIdentifier)) {
token.identifier = stream.lastMatch[1].toUpperCase() + (stream.lastMatch[2] || ''); // Canonicalize identifier name
} else if (stream.match(regexStringLiteral)) {
token.string = stream.lastMatch[1];
} else if (stream.match(regexNumberLiteral)) {
token.number = parseFloat(stream.lastMatch[0].replace(/\s+/g, ''));
} else if (stream.match(regexHexLiteral)) {
token.number = parseInt(stream.lastMatch[0].substring(1), 16);
} else if (stream.match(regexOperator)) {
token.operator = stream.lastMatch[0].replace(/\s+/g, '');
} else if (stream.match(regexSeparator)) {
token.separator = stream.lastMatch[0];
} else {
throw parse_error("Syntax error: Unexpected '" + source.substr(0, 40) + "'");
}
return token;
}
var lookahead = nextToken();
match = function match(type, value) {
if (!lookahead) {
throw parse_error("Syntax error: Expected " + type + ", saw end of file");
}
var token = lookahead;
if ('lineNumber' in token) {
currLineNumber = token.lineNumber;
}
lookahead = nextToken();
if (!{}.hasOwnProperty.call(token, type)) {
throw parse_error("Syntax error: Expected " + type + ", saw " + JSON.stringify(token));
}
if (value !== (void 0) && token[type] !== value) {
throw parse_error("Syntax error: Expected '" + value + "', saw " + JSON.stringify(token));
}
return token[type];
};
test = function test(type, value, consume) {
if (lookahead && {}.hasOwnProperty.call(lookahead, type) &&
(value === (void 0) || lookahead[type] === value)) {
if (consume) {
var token = lookahead;
if ('lineNumber' in token) {
currLineNumber = token.lineNumber;
}
lookahead = nextToken();
}
return true;
}
return false;
};
endOfStatement = function endOfStatement() {
return !lookahead ||
{}.hasOwnProperty.call(lookahead, 'separator') ||
{}.hasOwnProperty.call(lookahead, 'lineNumber');
};
endOfProgram = function endOfProgram() {
return !lookahead;
};
} (source));
//////////////////////////////////////////////////////////////////////
//
// Compiler utility functions
//
//////////////////////////////////////////////////////////////////////
function quote(string) {
return JSON.stringify(string);
}
//////////////////////////////////////////////////////////////////////
//
// Recursive Descent Parser
//
//////////////////////////////////////////////////////////////////////
var parseExpression, parseSubscripts;
//
// Type Checking
//
function parseAnyExpression() {
var expr = parseExpression();
return expr.source;
}
function enforce_type(actual, expected) {
if (actual !== expected) {
throw parse_error('Type mismatch error: Expected ' + expected);
}
}
function parseStringExpression() {
var expr = parseExpression();
enforce_type(expr.type, 'string');
return expr.source;
}
function parseNumericExpression() {
var expr = parseExpression();
enforce_type(expr.type, 'number');
return expr.source;
}
//
// Variables
//
parseSubscripts = function() {
var subscripts; // undefined = no subscripts
if (test('operator', '(', true)) {
subscripts = [];
do {
subscripts.push(parseNumericExpression());
} while (test('operator', ',', true));
match("operator", ")");
return subscripts.join(',');
}
return (void 0);
};
function parsePValue() {
var name = match('identifier'),
subscripts = parseSubscripts();
if (subscripts) {
identifiers.arrays[name] = true;
return '(function (value){state.parsevar(' +
quote(name) + ',[' + subscripts + '],value);})';
} else {
identifiers.variables[name] = true;
return '(function (value){state.parsevar(' +
quote(name) + ',value);})';
}
}
//
// Expressions
//
parseExpression = (function() {
// closure to keep things tidy
function parseUserfunction() {
var name = match('identifier'),
type = vartype(name) === 'string' ? 'string' : 'number',
expr;
// FUTURE: Allow differing argument type and return type
// (may require runtime type checks)
// Determine the function argument
match("operator", "(");
expr = type === 'string' ? parseStringExpression() : parseNumericExpression();
match("operator", ")");
return { source: 'lib.fn(' + quote(name) + ',' + expr + ')', type: type };
}
function parsefunction(name) {
if (!{}.hasOwnProperty.call(funlib, name)) {
throw parse_error("Undefined function: " + name);
}
match("operator", "(");
var func = funlib[name],
funcdesc = func.signature.slice(),
rtype = funcdesc.shift(),
args = [],
atype;
while (funcdesc.length) {
atype = funcdesc.shift();
if (/\?$/.test(atype)) {
if (test('operator', ')')) {
break;
} else {
atype = atype.substring(0, atype.length - 1);
}
}
if (args.length) {
match("operator", ",");
}
if (atype === 'string') {
args.push(parseStringExpression());
} else if (atype === 'number') {
args.push(parseNumericExpression());
} else {
throw new Error("Invalid function definition");
}
}
match("operator", ")");
return { source: 'funlib.' + name + '(' + args.join(',') + ')', type: rtype };
}
function parseFinalExpression() {
if (test('number')) {
return { source: String(match('number')), type: 'number' };
} else if (test('string')) {
return { source: quote(match('string')), type: 'string' };
} else if (test('reserved', kws.FN, true)) {
return parseUserfunction();
} else if (test('reserved')) {
return parsefunction(match('reserved'));
} else if (test('identifier')) {
var name = match('identifier'),
type = vartype(name) === 'string' ? 'string' : 'number',
subscripts = parseSubscripts();
if (subscripts) {
identifiers.arrays[name] = true;
return { source: 'state.arrays[' + quote(name) + '].get([' + subscripts + '])', type: type };
} else {
identifiers.variables[name] = true;
return { source: 'state.variables[' + quote(name) + ']', type: type };
}
} else {
match("operator", "(");
var expr = parseExpression();
match("operator", ")");
return expr;
}
}
function parseUnaryExpression() {
var rhs, op;
if (test('operator', '+') || test('operator', '-')) {
op = match('operator');
} else if (test('reserved', kws.NOT)) {
op = match('reserved');
}
if (op) {
rhs = parseUnaryExpression();
enforce_type(rhs.type, 'number');
switch (op) {
case "+": return rhs;
case "-": return { source: '(-' + rhs.source + ')', type: 'number' };
case kws.NOT: return { source: '((!' + rhs.source + ')?1:0)', type: 'number' };
}
}
return parseFinalExpression();
}
function parsePowerExpression() {
var lhs = parseUnaryExpression(), rhs;
while (test('operator', '^', true)) {
rhs = parseUnaryExpression();
enforce_type(lhs.type, 'number');
enforce_type(rhs.type, 'number');
lhs = { source: 'Math.pow(' + lhs.source + ',' + rhs.source + ')', type: 'number' };
}
return lhs;
}
function parseMultiplicativeExpression() {
var lhs = parsePowerExpression(), rhs, op;
while (test('operator', '*') || test('operator', '/')) {
op = match('operator');
rhs = parsePowerExpression();
enforce_type(lhs.type, 'number');
enforce_type(rhs.type, 'number');
switch (op) {
case "*": lhs = { source: '(' + lhs.source + '*' + rhs.source + ')', type: 'number' }; break;
case "/": lhs = { source: 'lib.div(' + lhs.source + ',' + rhs.source + ')', type: 'number' }; break;
}
}
return lhs;
}
function parseAdditiveExpression() {
var lhs = parseMultiplicativeExpression(), rhs, op;
while (test('operator', '+') || test('operator', '-')) {
op = match('operator');
rhs = parseMultiplicativeExpression();
switch (op) {
case "+":
enforce_type(rhs.type, lhs.type);
lhs = { source: '(' + lhs.source + '+' + rhs.source + ')', type: lhs.type }; break;
case "-":
enforce_type(lhs.type, 'number');
enforce_type(rhs.type, 'number');
lhs = { source: '(' + lhs.source + '-' + rhs.source + ')', type: lhs.type }; break;
}
}
return lhs;
}
function parseRelationalExpression() {
var lhs = parseAdditiveExpression(), rhs, op;
while (test('operator', '<') || test('operator', '>') || test('operator', '=')) {
op = match('operator');
switch (op) {
case '<':
if (test('operator', '=', true)) { op = '<='; break; }
if (test('operator', '>', true)) { op = '!=='; break; }
break;
case '>':
if (test('operator', '=', true)) { op = '>='; break; }
if (test('operator', '<', true)) { op = '!=='; break; }
break;
case '=':
if (test('operator', '<', true)) { op = '<='; break; }
if (test('operator', '>', true)) { op = '>='; break; }
if (test('operator', '=', true)) { op = '==='; break; }
op = '===';
}
rhs = parseAdditiveExpression();
enforce_type(rhs.type, lhs.type);
lhs = lhs = { source: '((' + lhs.source + op + rhs.source + ')?1:0)', type: 'number' };
}
return lhs;
}
function parseAndExpression() {
var lhs = parseRelationalExpression(), rhs;
while (test('reserved', kws.AND, true)) {
rhs = parseRelationalExpression();
enforce_type(lhs.type, 'number');
enforce_type(rhs.type, 'number');
lhs = {
source: '((' + lhs.source + '&&' + rhs.source + ')?1:0)',
type: 'number'
};
}
return lhs;
}
function parseOrExpression() {
var lhs = parseAndExpression(), rhs;
while (test('reserved', kws.OR, true)) {
rhs = parseAndExpression();
enforce_type(lhs.type, 'number');
enforce_type(rhs.type, 'number');
lhs = {
source: '((' + lhs.source + '||' + rhs.source + ')?1:0)',
type: 'number'
};
}
return lhs;
}
return parseOrExpression;
} ());
//
// Statements
//
function parseCommand() {
function slib(name /* , ...args */) {
var args = Array.prototype.slice.call(arguments, 1);
return 'lib[' + quote(name) + '](' + args.join(',') + ');';
}
var keyword = test('identifier') ? kws.LET : match('reserved'),
name, type, subscripts, is_to, expr, param, args, prompt, trailing, js;
switch (keyword) {
//////////////////////////////////////////////////////////////////////
//
// Variable Statements
//
//////////////////////////////////////////////////////////////////////
case kws.CLEAR: // Clear all variables
return slib('clear');
case kws.LET: // Assign a variable, LET x = expr
name = match('identifier');
subscripts = parseSubscripts();
match('operator', '=');
type = vartype(name);
if (type === 'int') {
expr = 'lib.toint(lib.checkFinite(' + parseNumericExpression() + '))';
} else if (type === 'float') {
expr = 'lib.checkFinite(' + parseNumericExpression() + ')';
} else { // type === 'string')
expr = parseStringExpression();
}
if (!subscripts) {
identifiers.variables[name] = true;
return 'state.variables[' + quote(name) + '] = ' + expr;
}
identifiers.arrays[name] = true;
return 'state.arrays[' + quote(name) + '].set([' + subscripts + '], ' + expr + ')';
case kws.DIM:
js = '';
do {
name = match('identifier');
subscripts = parseSubscripts();
identifiers.arrays[name] = true;
js += slib('dim', quote(name), '[' + subscripts + ']');
} while (test('operator', ',', true));
return js;
case kws.DEF: // DEF FN A(X) = expr
match("reserved", kws.FN);
name = match('identifier');
match("operator", "(");
param = match('identifier');
match("operator", ")");
match("operator", "=");
if (vartype(name) !== vartype(param)) {
throw parse_error("DEF FN function type and argument type must match");
}
expr = vartype(name) === 'string' ?
parseStringExpression() : parseNumericExpression();
return slib('def', quote(name),
'function (arg){' +
// Save the current context/variable so we can evaluate
'var rv,ov=state.variables[' + quote(param) + '];' +
// Swap in the argument
'state.variables[' + quote(param) + ']=arg;' +
// Evaluate the user-function expression
'rv=' + expr + ';' +
// Restore
'state.variables[' + quote(param) + ']=ov;' +
'return rv;' +
'}');
//////////////////////////////////////////////////////////////////////
//
// Flow Control Statements
//
//////////////////////////////////////////////////////////////////////
case kws.GOTO: // GOTO linenum
return slib('goto', match("number"));
case kws.ON: // ON expr (GOTO|GOSUB) linenum[,linenum ... ]
expr = parseNumericExpression();
keyword = match('reserved');
if (keyword !== kws.GOTO && keyword !== kws.GOSUB) {
throw parse_error("Syntax error: Expected " + kws.GOTO + " or " + kws.GOSUB);
}
args = [];
do {
args.push(match("number"));
} while (test("operator", ",", true));
return slib(keyword === kws.GOSUB ? 'on_gosub' : 'on_goto', expr, args.join(','));
case kws.GOSUB: // GOSUB linenum
return slib('gosub', match("number"));
case kws.RETURN: // Return from the last GOSUB
return slib('return');
case kws.POP: // Turn last GOSUB into a GOTO
return slib('pop');
case kws.FOR: // FOR i = m TO n STEP s
name = match('identifier');
if (vartype(name) !== 'float') {
throw parse_error("Syntax error: Expected floating point variable");
}
identifiers.variables[name] = true;
return slib('for',
quote(name),
match("operator", "=") && parseNumericExpression(),
match("reserved", kws.TO) && parseNumericExpression(),
test('reserved', kws.STEP, true) ? parseNumericExpression() : '1');
case kws.NEXT: // NEXT [i [,j ... ] ]
args = [];
if (test('identifier')) {
args.push(quote(match('identifier')));
while (test("operator", ",", true)) {
args.push(quote(match('identifier')));
}
}
return slib('next', args.join(','));
case kws.IF: // IF expr (GOTO linenum|THEN linenum|THEN statement [:statement ... ]
expr = parseAnyExpression();
js = slib('if', expr);
if (test('reserved', kws.GOTO, true)) {
// IF expr GOTO linenum
return js + slib('goto', match('number'));
}
match('reserved', kws.THEN);
if (test('number')) {
// IF expr THEN linenum
return js + slib('goto', match('number'));
}
// IF expr THEN statement
return js + parseCommand(); // recurse
case kws.END: // End program
return slib('end');
case kws.STOP: // Break, like an error
return slib('stop');
//////////////////////////////////////////////////////////////////////
//
// Error Handling Statements
//
//////////////////////////////////////////////////////////////////////
case kws.ONERR: // ONERR GOTO linenum
return slib('onerr_goto',
match("reserved", kws.GOTO) && match("number"));
case kws.RESUME:
return slib('resume');
//////////////////////////////////////////////////////////////////////
//
// Inline Data Statements
//
//////////////////////////////////////////////////////////////////////
case kws.RESTORE:
return slib('restore');
case kws.READ:
args = [];
do {
args.push(parsePValue());
} while (test("operator", ",", true));
return slib('read', args.join(','));
//////////////////////////////////////////////////////////////////////
//
// I/O Statements
//
//////////////////////////////////////////////////////////////////////
case kws.PRINT: // Output to the screen
args = [];
trailing = true;
while (!endOfStatement()) {
if (test('operator', ';', true)) {
trailing = false;
} else if (test('operator', ',', true)) {
trailing = false;
args.push('lib.comma()');
} else if (test('reserved', kws.SPC) || test('reserved', kws.TAB)) {
trailing = true;
keyword = match('reserved');
match("operator", "(");
expr = parseNumericExpression();
match("operator", ")");
args.push('lib.' + (keyword === kws.SPC ? 'spc' : 'tab') + '(' + expr + ')');
} else {
trailing = true;
args.push(parseAnyExpression());
}
}
if (trailing) {
args.push(quote('\r'));
}
return slib('print', args.join(','));
case kws.INPUT: // Read input from keyboard
prompt = '?';
if (test('string')) {
prompt = match('string');
match("operator", ";");
}
args = [];
do {
args.push(parsePValue());
} while (test("operator", ",", true));
return slib('input', quote(prompt), args.join(','));
case kws.GET: // Read character from keyboard
return slib('get', parsePValue());
case kws.HOME: // Clear text screen
return slib('home');
case kws.HTAB: // Set horizontal cursor position
return slib('htab', parseNumericExpression());
case kws.VTAB: // Set vertical cursor position
return slib('vtab', parseNumericExpression());
case kws.INVERSE: // Inverse text
return slib('inverse');
case kws.FLASH: // Flashing text
return slib('flash');
case kws.NORMAL: // Normal text
return slib('normal');
case kws.TEXT: // Set display mode to text
return slib('text');
//////////////////////////////////////////////////////////////////////
//
// Miscellaneous Statements
//
//////////////////////////////////////////////////////////////////////
case kws.NOTRACE: // Turn off line tracing
return slib('notrace');
case kws.TRACE: // Turn on line tracing
return slib('trace');
//////////////////////////////////////////////////////////////////////
//
// Lores Graphics
//
//////////////////////////////////////////////////////////////////////
case kws.GR: // Set display mode to lores graphics, clear screen
return slib('gr');
case kws.COLOR: // Set lores color
return slib('color', parseNumericExpression());
case kws.PLOT: // Plot lores point
return slib('plot',
parseNumericExpression(),
match("operator", ",") && parseNumericExpression());
case kws.HLIN: // Draw lores horizontal line
return slib('hlin',
parseNumericExpression(),
match("operator", ",") && parseNumericExpression(),
match("reserved", kws.AT) && parseNumericExpression());
case kws.VLIN: // Draw lores vertical line
return slib('vlin',
parseNumericExpression(),
match("operator", ",") && parseNumericExpression(),
match("reserved", kws.AT) && parseNumericExpression());
//////////////////////////////////////////////////////////////////////
//
// Hires Graphics
//
//////////////////////////////////////////////////////////////////////
// Hires Display Routines
case kws.HGR: // Set display mode to hires graphics, clear screen
return slib('hgr');
case kws.HGR2: // Set display mode to hires graphics, page 2, clear screen
return slib('hgr2');
case kws.HCOLOR: // Set hires color
return slib('hcolor', parseNumericExpression());
case kws.HPLOT: // Draw hires line
is_to = test('reserved', kws.TO, true);
args = [];
do {
args.push(parseNumericExpression());
match("operator", ",");
args.push(parseNumericExpression());
} while (test('reserved', kws.TO, true));
return slib(is_to ? 'hplot_to' : 'hplot', args.join(','));
//////////////////////////////////////////////////////////////////////
//
// Compatibility shims
//
//////////////////////////////////////////////////////////////////////
case kws.PR: // Direct output to slot
return slib('pr#', parseNumericExpression());
case kws.CALL: // Call native routine
return slib('call', parseNumericExpression());
case kws.POKE: // Set memory value
return slib('poke',
parseNumericExpression(),
match("operator", ",") && parseNumericExpression());
case kws.SPEED: // Output speed
return slib('speed', parseNumericExpression());
//////////////////////////////////////////////////////////////////////
//
// INTROSPECTION
//
//////////////////////////////////////////////////////////////////////
case kws.LIST: // List program statements
throw parse_error("Introspection statement not supported: " + keyword);
//////////////////////////////////////////////////////////////////////
//
// Statements that will never be implemented
//
//////////////////////////////////////////////////////////////////////
// Shape tables
case kws.ROT: // Set rotation angle for hires shape
case kws.SCALE: // Set rotation angle for hires shape
case kws.DRAW: // Draw hires shape
case kws.XDRAW: // XOR draw hires shape
throw parse_error("Display statement not supported: " + keyword);
// Interpreter Routines
case kws.CONT: // Continue stopped program (immediate mode)
case kws.DEL: // Deletes program statements
case kws.NEW: // Wipe program
case kws.RUN: // Execute program
throw parse_error("Interpreter statement not supported: " + keyword);
// Native Routines
case kws.HIMEM: // Set upper bound of variable memory
case kws.IN: // Direct input from slot
case kws.LOMEM: // Set low bound of variable memory
case kws.WAIT: // Wait for memory value to match a condition
case kws.AMPERSAND: // Command hook
throw parse_error("Native interop statement not supported: " + keyword);
// Tape Routines
case kws.LOAD: // Load program from cassette port
case kws.RECALL: // Load array from cassette port
case kws.SAVE: // Save program to cassette port
case kws.STORE: // Store array to cassette port
case kws.SHLOAD: // Load shape table from cassette port
throw parse_error("Tape statement not supported: " + keyword);
//////////////////////////////////////////////////////////////////////
//
// NYI Statements
//
//////////////////////////////////////////////////////////////////////
// Parts of other statements - AT, FN, STEP, TO, THEN, etc.
default:
throw parse_error("Syntax error: " + keyword);
}
}
//
// Top-level Program Structure
//
var parseProgram = function() {
var program = {
statements: [], // array of: [ line-number | statement-function ]
data: [], // array of [ string | number ]
jump: [] // map of: { line-number: statement-index }
};
function mkfun(js) {
var fun; // NOTE: for IE; would prefer Function()
eval('fun = (function (){' + js + '});');
return fun;
}
function empty_statement() { }
// Statement = data-declaration | remark | Command | EmptyStatement
// Command = identifier /*...*/ | reserved /*...*/
function parseStatement() {
if (test('data')) {
program.data = program.data.concat(match('data'));
return undefined;
} else if (test('remark', void 0, true)) {
return undefined;
} else if (test('reserved') || test('identifier')) {
return mkfun(parseCommand());
} else {
// So TRACE output is correct
return empty_statement;
}
}
// Line = line-number Statement { separator Statement }
function parseLine() {
var num = match('lineNumber');
var statements = [];
var statement = parseStatement();
if (statement) statements.push(statement);
while (test('separator', ':', true)) {
statement = parseStatement();
if (statement) statements.push(statement);
}
insertLine(num, statements);
}
function insertLine(number, statements) {
var remove = 0;
for (var i = 0, len = program.statements.length; i < len; ++i) {
if (typeof program.statements[i] !== 'number')
continue;
if (program.statements[i] < number)
continue;
if (program.statements[i] === number) {
var n = i;
do {
++n;
++remove;
} while (n < len && typeof program.statements[n] !== 'number');
}
break;
}
var args = [i, remove, number].concat(statements);
program.statements.splice.apply(program.statements, args);
}
// Program = Line { Line }
while (!endOfProgram()) {
parseLine();
}
// Produce jump table
program.statements.forEach(function(stmt, index) {
if (typeof stmt === 'number') {
program.jump[stmt] = index;
}
});
program.variable_identifiers = Object.keys(identifiers.variables);
program.array_identifiers = Object.keys(identifiers.arrays);
return program;
};
return parseProgram();
} ());
program.init = function init(environment) {
// stuff these into runtime library closure/binding
env = environment;
state = {
variables: {},
arrays: {},
functions: {},
data: this.data,
data_index: 0,
stmt_index: 0,
line_number: 0,
stack: [],
prng: new PRNG(),
onerr_code: 255,
onerr_handler: void 0,
trace_mode: false,
input_continuation: null,
clear: function() {
program.variable_identifiers.forEach(function(identifier) {
state.variables[identifier] = vartype(identifier) === 'string' ? '' : 0;
});
program.array_identifiers.forEach(function(identifier) {
state.arrays[identifier] = new BASICArray(vartype(identifier));
});
state.functions = {};
state.data_index = 0;
}
};
state.clear();
state.parsevar = function parsevar(name, subscripts, input) {
if (arguments.length === 2) {
input = arguments[1];
subscripts = void 0;
}
var value;
switch (vartype(name)) {
case 'string':
value = input;
break;
case 'int':
value = Number(input);
if (!isFinite(value)) { runtime_error(ERRORS.TYPE_MISMATCH); }
value = lib.toint(value);
break;
case 'float':
value = Number(input);
if (!isFinite(value)) { runtime_error(ERRORS.TYPE_MISMATCH); }
break;
}
if (subscripts) {
state.arrays[name].set(subscripts, value);
} else {
state.variables[name] = value;
}
};
};
program.step = function step(driver) {
function gotoline(line) {
if (!{}.hasOwnProperty.call(program.jump, line)) {
runtime_error(ERRORS.UNDEFINED_STATEMENT);
}
state.stmt_index = program.jump[line];
}
var stmt;
try {
// for RuntimeError
try {
if (state.input_continuation) {
var cont = state.input_continuation;
state.input_continuation = null;
cont(state.input_buffer);
} else if (state.stmt_index >= program.statements.length) {
return basic.STATE_STOPPED;
} else {
stmt = program.statements[state.stmt_index];
if (typeof stmt === 'number') {
state.line_number = stmt;
} else if (typeof stmt === 'function') {
if (state.trace_mode) {
env.tty.writeString('#' + state.line_number + ' ');
}
stmt();
} else {
throw "WTF?";
}
}
state.stmt_index += 1;
return basic.STATE_RUNNING;
} catch (e) {
// These may throw RuntimeError
if (e instanceof basic.RuntimeError) {
throw e; // let outer catch block handle it
} else if (e instanceof GoToLine) {
gotoline(e.line);
return basic.STATE_RUNNING;
} else if (e instanceof NextLine) {
while (state.stmt_index < program.statements.length &&
typeof program.statements[state.stmt_index] !== 'number') {
state.stmt_index += 1;
}
return basic.STATE_RUNNING;
} else if (e instanceof BlockingInput) {
// what to call on next step() after input is handled
state.input_continuation = e.callback;
// call input method to prepare async input
e.method(function(v) {
state.input_buffer = v;
if (driver) { driver(); }
});
return basic.STATE_BLOCKED;
} else if (e instanceof EndProgram) {
return basic.STATE_STOPPED;
} else if (e instanceof Error && /stack|recursion/i.test(e.message)) {
// IE: Error "Out of stack space"
// Firefox: InternalError "too much recursion"
// Safari: RangeError "Maximum call stack size exceeded"
// Chrome: RangeError "Maximum call stack size exceeded"
// Opera: Error "Maximum recursion depth exceeded"
runtime_error(ERRORS.FORMULA_TOO_COMPLEX);
} else if (e instanceof Error && /memory|overflow/i.test(e.message)) {
// IE: Error "Out of memory"
// Firefox: InternalError "allocation size overflow"
// Safari: Error "Out of memory"
// Chrome: (not catchable)
// Opera: (not catchable)
runtime_error(ERRORS.OUT_OF_MEMORY);
// NOTE: not reliably generated; don't unit test
} else {
throw e;
}
}
} catch (rte) {
if (rte instanceof basic.RuntimeError) {
state.onerr_code = rte.code || 0;
if (state.onerr_handler !== void 0) {
state.stack.push({
resume_stmt_index: state.stmt_index,
resume_line_number: state.line_number
});
gotoline(state.onerr_handler);
return basic.STATE_RUNNING;
} else if (rte.code === ERRORS.REENTER[0]) {
env.tty.writeString('?REENTER\r');
return basic.STATE_RUNNING;
} else {
// annotate and report to the user
rte.message += " in line " + state.line_number;
throw rte;
}
} else {
throw rte;
}
}
};
return program;
};
return basic;
} ());
// TODO: Unit tests for compile errors
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