ProtoScript

ProtoScript is a C reimplementation of an ECMAScript 1 core (almost JavaScript 1.3), designed as a minimal, embeddable scripting language.

It is a standalone command-line interpreter and does not target browsers, the DOM, HTML, or any client-side runtime.

The engine uses a glyph-based Unicode model (UTF-8), not UTF-16.

ProtoScript does not aim for modern JavaScript or browser compatibility.

Manifest

Prototype-Based Languages: A Different Way to Think

Demo

You can test ProtoScript immediately thanks to a demo running on the web via WebAssembly (compiled with emscripten):

Try it now: ppyne.github.io/ProtoScript/

Documentation

• The technical foundation: Object Creation with ES1
• Prototype-based OO explained through a linked list: One example can change everything
• User guide: docs/user_guide/toc.md
• Language reference: docs/language_reference.md
• ES1 deviations: docs/es1-notes.md
• String model spec: docs/specs/string-spec.md
• Io module spec: docs/specs/io_unified_spec.md
• GC spec: docs/specs/gc_spec.md
• ECMA-262 Edition 1 (June 1997): docs/specs/ECMA-262_1st_edition_june_1997.pdf
• License (BSD-3-Clause): LICENSE

Build (Simple, Complete)

Prerequisites

• C compiler toolchain (gcc, clang, etc.)
• libjpeg (for Image module)
• libpng (for Image module)
• SDL2 (for Display module)
• git
• awk
• cmake
• make

Install third_party submodules

git submodule update --init --recursive third_party/SDL third_party/libpng third_party/libjpeg

Build third_party (SDL2, libpng, libjpeg)

mkdir -p third_party/SDL/build
cmake -S third_party/SDL -B third_party/SDL/build -DCMAKE_BUILD_TYPE=Release
cmake --build third_party/SDL/build

mkdir -p third_party/libpng/build
cmake -S third_party/libpng -B third_party/libpng/build -DPNG_SHARED=OFF -DPNG_TESTS=OFF
cmake --build third_party/libpng/build

mkdir -p third_party/libjpeg/build
cmake -S third_party/libjpeg -B third_party/libjpeg/build -DENABLE_SHARED=OFF
cmake --build third_party/libjpeg/build

Build ProtoScript

make

Test ProtoScript

make test

Note: test 155-display-blit-limit opens an SDL window. In headless environments or CI, make test will auto-skip it if a display cannot be created, even when PS_ENABLE_MODULE_DISPLAY=1. To run this test, you need a working SDL2 setup with an available display server (macOS with a logged-in GUI, Linux X11/Wayland, or Windows desktop).

Clean

Remove everything that was built.

make clean

WebAssembly (WASM ou WebASM)

Note that ProtoScript is already be built in the web directory (you don't need to do the following).

If you really need to rebuild ProtoScript for WebAssembly, you must have Emscripten installed. Then you can do this:

make web-clean # clean the previous build
make web

Configure features

You may want to personalize your build of ProtoScript with these options in the file include/ps_config.h:

• PS_ENABLE_WITH (0/1): enable with
• PS_ENABLE_EVAL (0/1): enable eval
• PS_ENABLE_ARGUMENTS_ALIASING (0/1): enable arguments aliasing
• PS_ENABLE_MODULE_FS (0/1): enable Fs module
• PS_ENABLE_MODULE_IMG (0/1): enable Image module (PNG/JPEG decode + resample)
• PS_ENABLE_MODULE_DISPLAY (0/1): enable Display module (SDL2)
• PS_EVENT_QUEUE_CAPACITY (int): Event queue size
• PS_IMG_MAX_IMAGES (int): max live images
• PS_IMG_MAX_WIDTH (int): max image width
• PS_IMG_MAX_HEIGHT (int): max image height

All feature switches are compile-time flags.

Run ProtoScript

You can run ProtoScript in various ways:

./protoscript script.js
cat script.js | ./protoscript
echo 'Io.print("Hello world\n");'| ./protoscript
./protoscript < script.js
./protoscript - < script.js

Examples

Examples show core language usage and host modules:

• examples/misc/hello.js: minimal run
• examples/misc/basics.js: variables, loops, functions
• examples/misc/arrays.js: arrays
• examples/misc/strings.js: strings
• examples/misc/objects.js: objects
• examples/image/image_display.js: PNG decode + Display blit

and more in the examples/ directory.