I’m trying to write a regex that matches every occurrence of some_function(...), but it should not match when it’s part of an object method like my.some_function(...) or if it is a substring of another function, i.e., myname_some_function(...). The function can appear in various contexts, including within another function call, after whitespace, or standalone:

Cases that should match:

some_function(...)
other_function(some_function(...))
(some_function(...))
, some_function(...)
,some_function(...)
t some_function(...)
n some_function(...)

Cases that should not match:

myname_some_function(...)
object.some_function(...)

Constraints:
I cannot use negative lookbehind ((?<!.)) since the environment does not support it.
The some_function should not be preceded by a dot (.) or an alphanumeric character.

What I’ve tried so far:

'[^.]\s*some_function\s*\(.*'

This works in some cases but doesn’t handle when some_function appears after parentheses, e.g., other_function(some_function(...)).

'[^.\w]\s*some_function\s*\(.*'

This excludes object methods like my.some_function(), but fails when some_function appears right after an opening parenthesis or comma (e.g., , some_function(...), (some_function(...))).