The Asp Scripting Platform for Embedded Systems

Description

Asp is for Script Writers

The Asp language resembles basic Python (with some small differences), making it easy to learn for those who are already familiar with Python. It supports conditionals (if/elif/else), loops (while, for), and functions. It supports basic data types plus tuples, lists, sets, dictionaries, and ranges/slices. To keep things small, Asp does not support classes, exception handling, and many other advanced features.

Asp is Designed for Embedded Systems

Scripts are compiled to compact byte-code, which is checked for compatibility with the application before being allowed to run in the engine.

The Asp engine has a small code memory footprint (less than 100 KB when compiled optimizing for space). It avoids use of dynamic memory allocation and recursion, resulting in very little impact on the memory of the host application. Applications run scripts one instruction at a time, retaining a high frequency of control of the CPU. The engine supports blocking script functions without blocking the application. It works with bare-metal or OS-based applications. The engine is implemented entirely in C.

Build instructions

1. Asp is built using CMake. Issue the following commands to build the compiler, engine library, and standalone application for the host environment for Linux systems.

   $ mkdir build
   $ cd build
   $ cmake ..
   $ ccmake . # Optional. Review/update project settings.
              # If making changes, use c to configure, then g to generate.
   $ make
   

   For Windows systems, instead of using make, issue the following command to build the release configuration. Alternatively, the build can be performed from within the Visual Studio IDE. This step is not required if installing; see the next step.

   C:> msbuild asp.sln /property:Configuration=Release
   

2. The binaries may be installed on a Linux system using the following command after the build is complete.

   $ sudo make install
   

   For Windows systems, use the following command instead. Alternatively, as above, the install build may be performed from within the Visual Studio IDE. In either case, the build must typically be issued from a process with administrator priveleges.

   C:> msbuild INSTALL.vcxproj /property:Configuration=Release
   

   The following files are installed. PREFIX is e.g., /usr or /usr/local on Linux systems, "C:/Program Files (x86)/asp" on Windows systems. The version of ABI is designated by X.Y.

   • ${PREFIX}/bin/aspc - Asp compiler.
   • ${PREFIX}/bin/aspg - Asp application specification file generator.
   • ${PREFIX}/bin/asps - Standalone application.
   • ${PREFIX}/bin/aspinfo - Asp info utility.
   • ${PREFIX}/etc/asp/standalone.aspec - Standalone application spec.
   • ${PREFIX}/lib/libaspe.so - Asp engine library (shared build).
   • ${PREFIX}/lib/libaspe.a - Asp engine library (static build).
   • ${PREFIX}/lib/libaspm.so - Asp engine math library (shared build).
   • ${PREFIX}/lib/libaspm.a - Asp engine math library (static build).
   • ${PREFIX}/lib/libaspd.so - Asp info library (shared build).
   • ${PREFIX}/lib/libaspd.a - Asp info library (static build).
   • ${PREFIX}/include/asp-X.Y/asp*.h - Headers for application development.
   • ${PREFIX}/include/asps/X.Y/*.asps - Application spec include files.

Packaging instructions

Asp packages are built using CPack. A Python script, package.py, is provided that builds a standard set of packages for use on various platforms. A package may be used to install the software (source or binaries) instead of building and installing as described above.

Using the standalone application

Before running a script in the standalone application, set the ASP_SPEC_FILE environment variable to the standalone application specification file.

$ export ASP_SPEC_FILE=/usr/etc/asp/standalone.aspec

Alternatively, you can specify it on the compile command line, or copy/link the file to the local directory and rename it to app.aspec.

Now you can compile your script and run it under the standalone application. For Windows, you will need to have the appropriate bin directory in the PATH environment variable.

$ aspc my_script.asp
$ asps my_script

To display command line options for the standalone application, use the -h option.

$ asps -h

More information

• Web site: https://www.asplang.org/
• E-mail: [email protected]
• Source respositories:
  • https://bitbucket.org/asplang/ (development)
  • https://github.com/asplang/ (stable)
• Online documentation: https://asplang.bitbucket.io/
• License: See LICENSE.txt.