#summary A tutorial on the Cat language
#labels Documentation

= Introduction =

Cat is a [Functional functional] [StackLanguages stack-based programming language]. All operations in Cat manipulate a single shared stack.

If you type a number in Cat it is pushed onto the stack as so:

{{{
>> 2
stack: 2
>> 3
stack: 2 3
>> 4
stack: 2 3 4
}}}

If you write an operator it will apply to the top two items 

{{{
>> add
stack: 2 7
}}}

If you want to remove an item from the stack you can call `pop`:

{{{
>> pop 
stack: 2
}}}

You can also enter multiple numbers or instructions on the same line:

{{{
>> 4 4 add
stack: 2 8 
}}} 

You can remove all items from a stack by calling `clr`:

{{{
>> clr
stack: _empty_
}}}

The three basics instructions for manipulating the stack are:

  * `pop` - remove top item from stack
  * `dup` - duplicate top item on stack
  * `swap` - swap the top two items on the stack

== More Resources ==

  * The [http://www.cat-language.com/manual.html manual] has more in depth information about the language including a list of [http://www.cat-language.com/manual.html#primitives primitives]. 
  * The wiki contains several [http://code.google.com/p/cat-language/w/list?q=label:CodeExample code examples] 
  * The [Library standard library] contains definitions of many common functions.