Mouse (programming language)

The language described here is the later version of Mouse, as described in the Mouse book. This version is an extension of the language described in the original magazine article.

The following table describes each of the symbols used by Mouse. Here X refers to the number on the top of the stack, and Y is the next number on the stack.

These expressions appear frequently in Mouse programs.

X:           ~ store into variable X
X.           ~ recall variable X
X. Y:        ~ copy X into Y
N. 1 + N:    ~ increment N by 1
P. Q. P: Q:  ~ swap values of P and Q
? A:         ~ input a number and store in A
P. !         ~ print variable P

Mouse may input integers or characters. When a character is input, it is automatically converted to its ASCII code.

? X:         ~ input a number and store into X
?' X:        ~ input a character and store its ASCII code into X

Mouse may print integers, characters, or string constants, as shown in these examples. If an exclamation point appears in a string constant, a new line is printed.

X. !             ~ recall number X and print it
X. !'            ~ recall ASCII code X and print character
"Hello"          ~ print string "Hello"
"Line 1!Line 2"  ~ print strings "Line 1" and "Line 2" on two lines

A conditional statement has the general form:

B [ S ]  ~ equivalent to:  if B then S

Here B is an expression that evaluates to 1 (true) or 0 (false), and S is a sequence of statements.

Loops may have one of several forms. Most common are the forms:

(B ^ S)   ~ equivalent to:  while B do S
(S B ^)   ~ equivalent to:  repeat S until (not B)

Here again B is a boolean value (0 or 1), and S is a sequence of statements.

The format of a macro (subroutine) call may be illustrated by the following example. Macro A in this example adds the two parameters passed to it from the main program, and returns the sum on the top of the stack.

A,p1,p2;     ~ call in main program to macro A

...
$A 1% 2% + @  ~ macro A (add parameters p1 and p2)

Here p1 and p2 are parameters passed to the macro.

This short program prints 'Hello world.'

"Hello world."
$

This program displays the squares of the integers from 1 to 10.

1 N:              ~ initialize N to 1
( N. N. * ! " "   ~ begin loop; print squares of numbers
N. 10 - 0 < ^   ~ exit loop if N >= 10
N. 1 + N: ) $   ~ increment N and repeat loop

{{Reflist|2}}

• [http://users.encs.concordia.ca/~grogono/Mouse/mouse.html The Mouse Programming Language]
• [https://web.archive.org/web/20070307145837/http://www.geocities.com/fullerhaparnoldafmil/mouse.html The Great MOUSE Programming Language Revival]
• [https://archive.today/20030506120304/http://cth.dtdns.net/mouse/ Friends of the Mouse]
• [http://primepuzzle.com/mouse/mouse.html Mouse, the Language]
• [http://mouse.davidgsimpson.com Mouse: Computer Programming Language] (includes source code for Mouse interpreters)
• [http://mouse.sourceforge.net/ Information on sourceforge.net]

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Category:Stack-oriented programming languages