What is the main purpose of `FirSignatureEnhanceme...

# compiler

[Icyrockton]

What is the main purpose of FirSignatureEnhancement, is it to enhance the type of the JavaField, `JavaMethod`etc. based on the type in the overridden?

[dmitriy.novozhilov]

FirSignatureEnhancement converts declarations from java model into how it should look from the Kotlin side, including
• simple transformation of types
• mapping builtin types (java.lang.String -> kotlin.String)
• mapping collection types
• provide correct nullability (flexible types or regular types in presence of nullability annotations)
It also paired with FirJavaClassUseSiteMemberScope and JvmMappedScope, which also perform some other things, like
• creating properties based on java getters, if this getter overrides some kotlin property
• renames and transforms some java methods (e.g. in collections) to fir kotlin hierarchies (Map<K, R>.containsKey(Object key) -> Map<K, R>.containsKey(key: K)
• transforms some functions to properties (List.size() -> List.size)