Module: Rigor::ValueSemantics

Included in:
Cache::Descriptor::ConfigEntry, Cache::Descriptor::DependencyEntry, Cache::Descriptor::FileEntry, Cache::Descriptor::GemEntry, Cache::Descriptor::GlobEntry, Cache::Descriptor::PluginEntry, Type::AcceptsResult, Type::App, Type::BoundMethod, Type::DataClass, Type::DataInstance, Type::Difference, Type::Dynamic, Type::HashShape, Type::IntegerRange, Type::Intersection, Type::Nominal, Type::Refined, Type::Singleton, Type::StructClass, Type::StructInstance, Type::Tuple, Type::Union
Defined in:
lib/rigor/value_semantics.rb

Overview

Generates the value-object identity trio (== / eql? / hash) from a fixed field list. Every Rigor::Type carrier and the cache descriptor entries are immutable value objects that each hand-wrote the same three methods; forgetting a field in one of them (or letting == and hash disagree) silently corrupts Set / Hash-key behaviour — a carrier vanishes after its first insertion, or two distinct types compare equal.

The methods are CODE-GENERATED at class-definition time, not driven by per-call reflection, so they are as fast as the hand-written versions they replace — hash and == run on the inference hot path (type dedup, fact-store keys, memo caches), where a send-per-field would be a real regression.

Usage:

class Nominal
include Rigor::ValueSemantics
value_fields :class_name, :type_args
end

generates exactly:

def ==(other)
other.is_a?(self.class) && class_name == other.class_name && type_args == other.type_args
end
alias_method :eql?, :==
def hash
[self.class, class_name, type_args].hash
end

Value objects whose equality is NOT a plain field-wise comparison keep their hand-written == / hash and do not call value_fields — e.g. Type::Constant also distinguishes value.class (so Constant[1] != Constant[1.0]), and Type::Top / Type::Bot are field-free singletons.

Defined Under Namespace

Modules: ClassMethods

Class Method Summary collapse

Class Method Details

.included(base) ⇒ Object 



37
38
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# File 'lib/rigor/value_semantics.rb', line 37

def self.included(base)
  base.extend(ClassMethods)
end