{{stub}} {{language |site=http://www.jedsoft.org/slang/ |checking=dynamic }} S-Lang is a multi-platform programmer's library designed to allow a developer to create robust multi-platform software. It provides facilities required by interactive applications such as display/screen management, keyboard input, keymaps, and so on. The most exciting feature of the library is the slang interpreter that may be easily embedded into a program to make it extensible. While the emphasis has always been on the embedded nature of the interpreter, it may also be used in a stand-alone fashion through the use of slsh, which is part of the S-Lang distribution.

Unlike many interpreters, the S-Lang interpreter supports all of the native C integer types (signed and unsigned versions of char, short, int, long, and long long), and both single and double precision types, as well as a double precision complex type. Other data types supported by the interpreter include strings, lists, associative arrays (hashes), user-defined structures, and multi-dimensional arrays of any data-type.

The S-Lang interpreter has very strong support for array-based operations making it ideal for numerical applications. (from [http://www.jedsoft.org/slang/ the official web site]])

For simplicity, many of the S-Lang tasks use the print() function. This is not part of S-Lang per se, but is normally included in the S-Lang shell "slsh". If it is missing, or you're using some other S-Lang environment, options include C-like fputs(), sprintf() and printf(). Their format and parameters work about like you'd expect in a C-inspired interpreted language.

sprintf(f, d..) [f=string format, d..=zero or more data items] returns a string. printf(f, d..) prints to "stdout" and returns the number of items formatted. fputs(s, fp) prints string s to the file-pointer fp and returns the string length or -1 on error. Remember S-Lang is a "stack language", so even if you don't care about the return value, your code should "eat" it:

() = printf("S-Lang: %d tasks and counting!\n", 23);

() = fputs("the quality of mercy is not strnen\n", stdout);

You can approximate print() with the following; NOTE the capital-S, which implicitly calls the string() function to convert-or-describe non-strings as strings:

define print(foo) { () = printf("%S\n", foo); }

S-Lang is the extension language for the lightweight Emacs-like [http://www.jedsoft.org/jed/ programmer's editor Jed]. There, the output functions include:

insert(s)       write string s into current buffer
vinsert(f,d..)  insert(sprintf(f, d..)) ["variable"] equivalent

message(s)      write string s into "mini-buffer"
vmessage(f,d..) message(sprintf(f, d..)) equivalent

error(s)        like message(), but in error-color, then cancel cmd
verror(f, d..)  error(sprintf(f, d..)) equivalent

== See Also == [[wp:S-Lang_(programming_language)|Wikipedia:S-Lang(programming language)]]