[REBOL] Fun with blocks and ops.
From: fsievert:uos at: 10-Oct-2000 14:09
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