pocketlang

A lightweight, fast embeddable scripting language.

ThakeeNathees
1522
80
C

Pocketlang is a lightweight (~3000 semicolons) and fast
object oriented, embeddable scripting language written in C. It has a ruby
flavoured python syntax, that can be learned within 15 minutes.
Including the compiler, bytecode VM and runtime, it’s a standalone executable
with zero external dependencies just as it’s self descriptive name. The pocketlang
VM can be embedded in another hosting program very easily.

Wren Language and their wonderful book Crafting Interpreters
were used as a reference to write this language.

What pocketlang looks like

# Python like import statement.
from time import clock as now

# A recursive fibonacci function.
def fib(n)
  if n < 2 then return n end
  return fib(n-1) + fib(n-2)
end

# Prints all fibonacci from 0 to 10 exclusive.
for i in 0..10
  print("fib($i) = ${fib(i)}")
end

Try It Now

You can try pocketlang on your browser.
It’s a WebAssembly build of the VM compiled using emscripten.
Note that in the webassembly version of the language, some features (input, file handling, relative import, etc.)
have disabled, has limited memory allocations, and the stdout calls might be slower.

Documentation

The pocketlang documentation is hosted at https://thakeenathees.github.io/pocketlang/ which
is built from the docs branch generated by a little python script at docs/generate.py.
Note that the documentations are WIP and might not be up to date.

Performance

Pocketlang uses NaN-Boxing which is a memory efficient way to represent
dynamic types and dealing with them are much faster. It supports tail call
optimization. When a function returns a call, the callee can re-use the
caller’s stack frame, this will optimize memory from O(n) to O(1) and for tail recursive
it’ll completely prevent stackoverflows and yet it’s faster.

All benchmarks below were executed on: Windows10 (64bit), ASUS N552VX, Intel Core i7-6700HQ 2.6GHz
with 12GB SODIMM Ram. And the language versions are: pocketlang (pre-alpha), wren v0.3.0,
python v3.7.4, ruby v2.7.2.

performance

The source files used to run benchmarks can be found at test/benchmarks/
directory. They were executed using a small python script in the test directory.

Building From Source

It can be build from source easily without any dependencies, or additional requirements
except for a c99 compatible compiler. It can be compiled with the following command.

GCC / MinGw / Clang (alias with gcc)

gcc -o pocket cli/*.c src/core/*.c src/libs/*.c -Isrc/include -lm -ldl

MSVC

cl /Fepocket cli/*.c src/core/*.c src/libs/*.c /Isrc/include && rm *.obj

Makefile

make

To run the make file on windows with mingw, you require the GNU make tool which you can get
from msys2 or cygwin.

Windows batch script

scripts\build.bat

You don’t have to run the script from a Visual Studio .NET developer command prompt, It’ll search
for the MSVS installation path and setup the build environment.

For other compiler/IDE

  1. Create an empty project file / makefile.
  2. Add all C files in the src/core/ directory.
  3. Add all C files in the src/libs/ directory.
  4. Add all C files in the cli/ directory.
  5. Add src/include to include path.
  6. If *nix link m, dl
  7. Compile.

Visual studio project files can be generated with the premake, see
scripts/README
for more information. If you weren’t able to compile it, please report
us by opening an issue.

References