gromgit / little-lang

The Little Programming Language

INTRODUCTION

Little is a compiled-to-byte-code language that draws heavily from C and Perl. From C, Little gets C syntax, simple types (int, float, string), and complex types (arrays, structs). From Perl, Little gets associative arrays and regular expressions (PCRE). And from neither, Little gets its own simplistic form of classes.

The name "Little", abbreviated as simply "L", alludes to the language's simplicity. The idea was to distill the useful parts of other languages and combine them into a scripting language, with type checking, classes (not full-blown OO but useful none the less), direct access to a cross-platform graphical toolkit, and a library drawn from Perl and the standard C library.

L is built on top of the Tcl/Tk system. The L compiler generates Tcl byte codes and uses the Tcl calling convention. This means that L and Tcl code may be intermixed. More importantly, it means that Little may use all of the Tcl API and libraries as well as TK widgets. The net result is a type-checked scripting language which may be used for cross-platform GUIs.

Little is open source under the same license as Tcl/TK (BSD like) with any bits that are unencumbered by the Tcl license also being available under the Apache License, Version 2.0.

Little is based on interim Tcl and Tk releases http://core.tcl.tk/tcl/info/497b93405b3435aa and http://core.tcl.tk/tk/info/407bae5e576b5ef7.

PREREQUISITES

• bison
• flex
• libxft2-dev

COMPILING L

Little can be built with or without Tk. Without Tk, you get only an tclsh executable named "L". With Tk, you get that and a version of wish with Little named "L-gui" (on OS X, an application bundle is created instead). The accompanying Makefile builds L and L-gui for Linux, OS X, and Windows.

Because Little is integrated into Tcl/Tk, the instructions for configuring and compiling Tcl and Tk apply. See tcl/README and tk/README if you need to tweak anything. L adds Perl-compatible regular expressions (PCRE) and the --with-pcre=<path> configure option to Tcl.

A Windows build wants msys or cygwin. A make help explains the make targets.

L uses git submodules to distribute Tcl, Tk, and PCRE. To compile from source:

$ git submodule init
$ git submodule update
$ make

INSTALLING

On Linux and Windows, a make install will install L and L-gui in /usr/local/bin (can be overridden with L_INSTALL_DIR=$DIR).

WARNING: If you have Tcl/Tk version 8.6 installed in /usr/local, running make install will stump on your installation.

For OS X, Little is similarly installed, but the L-gui application bundle is copied to LGUI_OSX_INSTALL_DIR which defaults to /Applications.

DOCUMENTATION

On Linux, make install will create $(INSTALL_DIR)/doc/L/L.html but not on macos or windows (yet, it needs L to build and the path to Little is hard coded in tcl/doc/L/pod2html.l. Someone should fix this :)

See tcl/doc/l-paper for "The L Programming language" published in the Proceedings of the 17th Tcl/Tk Conference.