The uppercase operation converts all letters in a string to their Unicode
uppercase equivalents. It takes a single string input and produces a new string
with each character mapped to its uppercase form.
The syntax of the uppercase operation is:
[ $destination ] uppercase inputString
The $destination identifier is optional. If omitted, the result is bound to
the special slot _. The inputString argument is required and must be a
string value or an identifier bound to a string.
For example, to convert a literal string to uppercase and bind it to shout:
$shout uppercase “Hello, Gendo!”
This produces "HELLO, GENDO!" bound to shout.
If no destination is provided, the current value of _ is converted and
rebound to _:
uppercase
Given that _ holds "good morning", after this instruction _ will hold
"GOOD MORNING".
The uppercase operation does not modify its input. It returns a new string,
leaving the original value unchanged. Identifiers follow the single‑assignment
rule; attempting to reassign an existing name will result in an error. Invalid
usage—such as omitting inputString when no destination is provided, or
supplying a non‑string value—results in a compile‑time or runtime error.