fth-ship / higgs

Higgs JavaScript Virtual Machine

Higgs

Higgs JavaScript Virtual Machine

An interpreter and JIT compiler for JavaScript targetting x86-64 platforms.

Requirements:

• D compiler (DMD recommended)
• POSIX compliant OS (Linux, Unix, MacOS X)
• x86 64-bit CPU (if using the JIT compiler)
• Python 2.7 (if regenerating object layouts or instruction encodings)

Quickstart:

Get the source:

git clone https://github.com/maximecb/Higgs.git && cd Higgs/source

Compile a binary:

make all generates a binary higgs in the source directory.

Install (optional):

make install copies the higgs binary to /usr/bin and the runtime files to /etc/higgs.

Cleanup:

make clean will remove any binaries in the source directory.

You may wish to run the unit tests:

make test generates a binary test-higgs and tests its proper functioning.

For further info, see the makefile.

Usage:

higgs will start Higgs and give you a REPL (read-eval-print loop).

To execute one or more files, pass them to higgs:

higgs file1.js file2.js

The --e option accepts a string to execute:

higgs --e "var x = 4; x = x + 5; print(x)"

The --repl option will start a REPL after evaluating a string and/or files:

higgs --repl file1.js will evaluate file1.js and then start a REPL.

higgs file1.js will evaluate file1.js and then exit.

The --jit_disable option will disable the JIT compiler and rely solely on the interpreter.

The --jit_dumpasm option will dump the assembler code generated by the JIT to the console.

Notes:

• You may wish to use rlwrap for a better REPL experience.

Libraries

console:

Higgs has a library to to allow you to pretty-print objects/data to stdout.

Importing:

// To us use the console functions you must import the console module:
var console = require('lib/console');

Functions:

// To pretty-print
console.log("foo");
console.log({ foo: "bar"});
// If you pass multiple arguments, they will be printed on the same line separated by tabs
console.log(1, 2, 3);

csv:

The csv library provides basic support for manipulating comma-separated value (CSV) files.

Importing:

// First import the csv module:
var csv = require('lib/csv');

Writing CSV files:

// Create a new CSV spreadsheet object
sheet = new csv.CSV();

// Data can be added to the spread sheet row by row
sheet.addRow(['name', 'age', 'sex']);
sheet.addRow(['Alice', '19', 'F']);
sheet.addRow(['Bob', '22', 'M']);
sheet.addRow(['Kirby', '1', 'N/A']);

// You can set individual cell values directly using the setCell method
// This will change Alice's name to Anna:
sheet.setCell(1, 0, 'Anna');

// Rows can also be directly addressed with the setRow method
// This replaces the last row:
sheet.setRow(3, ['John', '35', 'M']);

// Write the data to a CSV file
sheet.writeFile('data.csv');

Reading CSV files:

// Read a spreadsheet from a CSV file
sheet = csv.readFile('data.csv');

// Prints 4
print(sheet.getNumRows());

// Prints 'John'
print(sheet.getCell(3, 0));

stdio:

Higgs has a library to provide common I/O functionality. It is a wrapper around the C I/O functions found in the stdio library.

Importing:

// To use the I/O functions you must first import the stdio module:
var io = require('lib/stdio');

File operations:

// The stdio module provides some common file operations

// Delete a file, returns true if successful or false otherwise
io.remove('test.txt');

// Rename a file, returns true if successful or false otherwise
io.rename('foo.txt', 'bar.txt');

// Get a temporary file, returns a File object on success or throws error on failure
var myfile = io.tmpfile();

// Get a unique name, returns a string containing the name on success or throws error on failure
var name = io.tmpname();

// Open a file, returns a File object on success or throws error on failure
// open foo.txt for reading
var foo = io.fopen("foo.txt", "r");

File objects:

// Some functions like fopen return an instance of File:
var myfile = io.fopen("foo.txt", "w+");

// File objects provide methods for reading, writing, etc

// Get a character, will return "" for EOF
var c = myfile.getc();

// Read a line, including newline
var line = myfile.readLine();

// You can also specify a maximum length to read
// the next read will get the remainder of the line (if any)
var first_ten_chars = myfile.readLine(10);
var remainder = myfile.readLine();

// Read the next x chars
var ten_chars = myfile.read(10);

// Read the entire file
var test = myfile.read();

// There are functions for reading binary data:
var answer = file.readUint8();
var steps = file.readInt8();
var spartans = file.readUint16();
var years = file.readInt16();
var jnumber = file.readUint32();
var population = file.readFloat64();

// Write a char to the file, returns true if successful or false otherwise
myfile.putc("H");

// Write a string to the file, returns true if successful or false otherwise
myfile.write("Hello World.");

// There are functions for writing binary data:
file.writeUint8(42);
file.writeInt8(8);
file.writeUint16(300);
file.writeInt16(100);
file.writeUint32(8675309);
file.writeFloat64(1.536);

// Flush a file, returns true if successful or false otherwise
myfile.flush();

// Returns true if the next character is EOF
myfile.EOF();

// Returns the current position in the file
myfile.tell();

// Rewind to beginning of file
myfile.rewind();

// Seek to 10th character
myfile.seek(10);

// Seek 2 characters ahead
myfile.seek(2, io.SEEK_CUR);

// When finished with a file close() will close it and free some resources
myfile.close();

The stdin/stdout/stderr streams:

// The stdio module provides File objects for stdin/stdout/stderr

// Get a char from stdin
io.stdin.getc();

// Write to stdout
io.stdout.write("Hello!");

// Write to stderr
io.stderr.write("Hello!");

stdlib:

The stdlib library provides wrappers for common functions in the C stdlib.

Importing:

// First import the stdlib module:
var stdlib = require('lib/stdlib');

The following functions are provided:

// Allocate memory with malloc
var mem = stdlib.malloc(32);

// Resize/reallocate memory
mem = stdlib.realloc(64);

// Free memory
stdlib.free(mem);

// Get the value of an environmental variable
var name = stdlib.getenv("LOGNAME");

// Execute a command
stdlib.system("ls -a");

// There is also popen, which will return a file-like object
var output = stdlib.popen("ls -a", "r");
print(output.read());

// Exit with return code
stdlib.exit(0);

Notes:

• There is currently no support in stdio for wchar functions.
• Functions in the stdio library must be called in the context of the stdio module. var fopen = io.fopen will not work.