[REBOL] Fun with blocks and ops.

[fsievert]

Here some fun with a self-modifying block :)

>> a: [append a [+ 1] 1]
== [append a [+ 1] 1]
>> do a   
== 1
>> do a
== 2
>> do a
== 3
>> do a
== 4
>> do a
== 5
>> do a
== 6             <---- !
>> do a
== 8             <---- !
>> do a
== 9

And even more fun is:

>> a: [append a '+ append a 1 1] 
== [append a '+ append a 1 1]
>> do a
== 1
>> do a
== 2
>> do a
== 3
>> do a
== 4
>> do a
== 5
>> do a
== 7       <-----
>> do a
== 8

[ ..... ]

>> do a
== 12
>> do a
** Script Error: Operator is missing an argument.
** Where: 1 + 1 + 1
>> do a
== 13
>> do a
== 15   <-------
>> do a
== 16
>> do a
== 17

[ .... ]

>> do a
== 28
>> do a
** Script Error: Operator is missing an argument.
** Where: 1 + 1 + 1
>> do a
== 29
>> do a
== 31