Category:Ursa

Ursa
This programming language may be used to instruct a computer to perform a task.

Official website

Execution method:	Interpreted
Garbage collected:	No
Type strength:	Strong
See Also:	Ursa on the HOPL

Listed below are all of the tasks on Rosetta Code which have been solved using Ursa.

About

Ursa is a simple programming language that I've been working on for awhile now. Its syntax is (at times) similar to Lisp, but instead of being list-based, it is "stream-based." Most in-built statements operate on types of data called streams. Streams are are variable-length arrays of data of a certain type.

The basic premise of ursa is to function as a very high-level abstraction layer between streams and "I/O devices." I/O devices are objects that represent locations that can be read and written using data streams; namely, the console, files, and network ports. Ursa greatly simplifies the implementation of programs that transfer data between these devices.

Ursa uses reverse polish notation for math and functions are simply seperated from their arguments by space characters. This makes implentation of Standard Ursa interpreters since this syntax is easier to write a parser for.

Example Code

Raw File Transfer

This Ursa code opens a port on a remote server, then outputs the specified file to the port. <lang ursa> if (< (size args) 4) out "usage: " args<0> " [server] [port] [file]" endl console stop end if

decl file f decl port p f.open args<3> p.connect args<1> (int args<2>) out (f.readall) p f.close p.close </lang>

Single-User Echo Server

<lang ursa># declare a serverport and a port to attach new connections to declare serverport sp declare port p

1. declare a string to contain lines of input

declare string input

1. attach the serverport to port 20000

sp.attach 20000

1. loop indefinitely, getting connections then echoing the data they send

while true

       set p (sp.getconn)
       out "%msg: connection from " (p.addr) endl console
       out "echo server " _version endl endl p
       while true
               set input (in string p)
               out input endl p
               if (and (= input "") (not (p.isopen 1000)))
                       break
               end if
       end while
       p.close
       out "%msg: connection closed" endl console

end while</lang>

See Also

• Ursa homepage