negative skip + variable

[pepiporn]

Code:

>> a
== ["hugo" "biene" "foo" "bar" "red red wine" "reggae music"]
>> x
== 2
>> skip a x
== ["foo" "bar" "red red wine" "reggae music"]
>> skip tail a -x
** Script Error: -x has no value
** Near: skip tail a -x
>> skip tail a -2
== ["red red wine" "reggae music"]

hope you get what i want. skip from the end of a series with a variable length ( to get last 2, or last 5 or last 10, or ... )

... at this occasion: how can i get the last 3 without the very last item? ( would be for that example: [ "foo" "bar" "red red wine" ] )
 

[Gabriele]

You just need a space between "-" and "x". (Without, "-x" is a single word.)

Code:

>> skip tail a (- x)
== ["red red wine" "reggae music"]
>> skip tail a negate x
== ["red red wine" "reggae music"]
>> skip tail a x * -1
== ["red red wine" "reggae music"]

Also, for those used to BASIC (this is something that gets asked very often):

Code:

>> left: func [series number] [copy/part series number]
>> right: func [series number] [copy skip tail series negate number]
>> mid: func [series start number] [copy/part at series start number]
>> left a 3
== ["hugo" "biene" "foo"]
>> right a 3
== ["bar" "red red wine" "reggae music"]
>> mid a 3 3
== ["foo" "bar" "red red wine"]
>> mid tail a -4 3
== ["foo" "bar" "red red wine"]