Struct.new in LowType.config allocates a new anonymous class on every call

[obsidiannnn]

Problem

In low_type.rb, the config method is defined as:

def config
  config = Struct.new(:type_checking, ...)
  @config ||= config.new(true, ...)
end

Struct.new(...) runs on every invocation of LowType.config , it only memoizes the instance via @config ||=, not the Struct class itself. Every call allocates a new anonymous Struct class that is immediately discarded.

Impact

LowType.config.type_checking is called on every method redefine. In a library where minimal overhead is a core goal, allocating and discarding an anonymous class on every config access is real unnecessary work ... minor but avoidable.

Reproduction

# Every call to LowType.config allocates a new Struct class
LowType.config  # => allocates Struct class, discards it, returns memoized instance
LowType.config  # => allocates another Struct class, discards it, returns memoized instance

Proposed Fix

Hoist the Struct definition to a constant so it is created once:

Config = Struct.new(:type_checking, ...)

def config
  @config ||= Config.new(true, ...)
end

This allocates the Struct class once at load time and memoizes both the class and the instance.

[obsidiannnn]

Hey @maedi
Found a minor but real inefficiency in LowType.config ... Struct.new is being called on every invocation, allocating a new anonymous class each time that gets immediately discarded. Opened issue #35 with a proposed fix.
Let me know if the direction looks right!

[maedi]

Great find, let's fix it!