LDPL Docs

Introduction

The LDPL Community has compiled this document with the desire to teach and standardize the LDPL programming language. This document contains the specification for the LDPL programming language, as well as explanations, instructions and examples for every feature included in it.

LDPL

Feedback, corrections and suggestions are welcome, both on the main LDPL repository or by e-mail to [email protected]. You can join the LDPL community at r/ldpl or via IRC on irc.freenode.net channel #ldpl.

The source code for this documentation is available in the LDPL repository.

About LDPL

LDPL is a powerful compiled programming language designed from the ground up to be expressive, readable, fast and easy to learn. It mimics plain English, in the likeness of the good parts of older programming languages like COBOL, with the desire that it can be understood by anybody. It's highly portable and runs on a plethora of different architectures and operating systems including AMD-64, ARMv8 and PowerPC Linux and Mac OS X. It also supports UTF-8 out of the box.

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# LDPL 'Hello World' example

data:
name is text # Your name will go here.

procedure:
display "Hello World!" lf "What's your name? "
accept name
display "你好, " name ", welcome to LDPL!" lf

LDPL also aims to suppress unreadable code and redundancy by only having one way of doing anything. What a command does should never overlap with the purpose of another command and, as such, every LDPL command does one and only one thing. Every line is a step further towards the completion of an algorithm, no more, no less.

The LDPL Compiler

To use LDPL, you should first download or compile the LDPL compiler. For more information on how to do that, read the How to install LDPL section on the LDPL Readme.

To use the compiler, you must have a C++ compiler already installed on your system and have mapped it to c++, found on your PATH. The LDPL Compiler compiles LDPL code to C++ code and thus this is a requirement for it to work.

Once the compiler is set up, go write some LDPL source code, say source.ldpl. Then compile the source code using ldpl source.ldpl. The compiled, executable binary file will be saved as source-bin. Done!

Compiler Switches

To use the LDPL compiler, the syntax is as follows:

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ldpl [-i='<included file>']... <source file>|-c
     [-o='<output name>'|-r] [-f='<c++ flag>']... [-n]
ldpl [-v|-h]

The -f flag can be used to pass extra options to the c++ compiler when. For example, -f=-lSDL could be used to link against SDL. The flag statement can also be used as well (flag "-lSDL") and its use is recommended. More on this later.

By using -r you can just compile your project and print the C++ representation for that code.

You can set the filename for the compiled binary with the -o flag. For example, if you want to name your program "dog", you could compile it with ldpl -o=dog main.ldpl.

On Linux platforms, LDPL builds static binaries by default. If you want to build non-static ones use the -ns flag.

The -c flag tells LDPL to accept source code from the standard input.

You can import extra files and extensions to your LDPL compilation by using the -i= flag. Extensions can be imported by passing .o, .a, or .cpp files to this flag; see the Extensions section for more information. The use of the INCLUDE statement is preferred.

-v and --version print out version info and release details.

-h and --help print this list of options.

File Extensions

The preferred file extension for LDPL source files is '.ldpl'. The extension '.lsc' (LDPL Source File) should also be accepted in case the preferred extension couldn't be used for any reason.

Tip

File extensions are important: they help editors to recognize what language your source code is written in and they tell the LDPL compiler how to treat your files.

License

This LDPL Compiler is distributed under the Apache 2.0 License. All LDPL Dinosaur logos where created by Lartu and are released under a Creative Commons Attribution 4.0 International (CC BY 4.0) license. This documentation is released under the Apache 2.0 License.