How to pass computed value for column1 onto column2 in update - plsql

Question

First of all, I am using plsql, and adapting an existing command. I probably would have done it differently from scratch.
I want to do something of this kind, but this doesn't work.
UPDATE TABLE_NAME
SET COLUMN1 = FUNCTION1(...)
, COLUMN2 = FUNCTION2(..., COLUMN1)
;
Ideally, I would like to avoid doing this
UPDATE TABLE_NAME
SET COLUMN1 = FUNCTION1(...)
, COLUMN2 = FUNCTION2(..., FUNCTION1(...))
;
Is there any way of achieving this, maybe by storing the computed value for COLUMN1 into a variable?
For example, in C, something like this would be possible.
COLUMN1 = VARIABLE_NAME = FUNCTION1(...)
Or maybe by positionally referring to it? This syntax doesn't work, but I have a vague idea that it might be possible.
UPDATE TABLE_NAME
SET COLUMN1 = FUNCTION1(...)
, COLUMN2 = FUNCTION2(..., {1})
;
Thanks.

Answer 1

If you are doing this in PL/SQL then you can call the functions, assigned the return value to variables and then use those variables to update the table. Like:
lv_col1 := function1(...);
lv_col2 := function2(...,lv_col1);
update table
set column1 = lv_col1,
column2 = lv_col2
This way you don't have to call the function1 multiple times.