Module rule 

AIM rule representation and parsing.

A Rule models a single AIM entry: identifier, typedef, expression, and value. Identifiers classify rules:

• UPPERCASE → modifier
• lowercase → assignment
• other/mixed → general evaluation.

Structs

Rule

Single AIM rule: identifier, typedef, expression, and value.

Functions

is_lowercase

Check if a string contains only lowercase characters.

is_uppercase

Check if a string contains only uppercase characters.

parse_rule

Parse a rule from a single AIM line.

test_for_assignment

Test if an identifier should be considered an assignment rule.

test_for_modifier

Test if an identifier should be considered a modifier rule.