How can I change a global variable that have the same name as a local variable in Rebol or Red?

Question

I cannot change the value of global variable a within f because it has the same name as a local variable: when function returns, a is still 1 instead of 12.

a: 1
f: func[a][set 'a a]
>> f 12
== 12
>> a
== 1

How can I refer to global variable a ? Isn't set supposed to only refer to global variable ? Am I obliged to change my local variable name to do so or is there a way to keep both name ?

*"Isn't set supposed to only refer to global variable"* What you might be thinking of is the difference between using a SET-WORD! in a FUNCTION body--which is gathered to suggest you want a local automatically--vs. avoiding the use of any SET-WORD!s in a FUNCTION body at all and doing an assignment via SET of a LIT-WORD!, in which case the binding that the LIT-WORD! you are assigning had in the body code prior to FUNCTION will be used for the assignment. *(Yes, this is kind of Rube-Goldberg-inspired. :-P)* — HostileFork says dont trust SE, Nov 04 '17 at 16:14

score 3 · Accepted Answer · answered Nov 04 '17 at 13:20

3

Use system/words/ path prefix to force read or write access to a word in global context:

>> a: 1
>> f: func[a][system/words/a: a]
== func [a][system/words/a: a]
>> f 12
== 12
>> a
== 12

answered Nov 04 '17 at 13:20

DocKimbel

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How can I change a global variable that have the same name as a local variable in Rebol or Red?

1 Answers1