Method HashCode

pkg/expression/expression.go:252–252

HashCode creates the hashcode for expression which can be used to identify itself from other expression. It generated as the following: Constant: ConstantFlag+encoded value Column: ColumnFlag+encoded value ScalarFunction: SFFlag+encoded function name + encoded arg_1 + encoded arg_2 + ...

()

	// Column: ColumnFlag+encoded value
	// ScalarFunction: SFFlag+encoded function name + encoded arg_1 + encoded arg_2 + ...
	HashCode() []byte

	// CanonicalHashCode creates the canonical hashcode for expression.
	// Different with `HashCode`, this method will produce the same hashcode for expressions with the same semantic.