News for hackers. Stuff that matters.

A comment on Using the Specification Pattern to Build a Data-Driven Rules Engine. Parent comment

Re:Using the Specification Pattern to Build a Data-Driven Ru... by pacala on Tuesday March 24, 2020 @12:40PM (#22676118)
Feeling cranky today, lockdown and everything. This is an elementary interpreter, clumsily implemented because of all the object oriented cruft.
[ Parent | on HN ]
Re:Using the Specification Pattern to Build a Data-Driven Ru... by agentultra on Tuesday March 24, 2020 @01:20PM (#22676541)
Indeed... in Haskell this can be implemented with a GADT and an evaluator which is really easy to express.

Still useful to know the "pattern" regardless of OOP cruft, Javascript prototypes, or Haskell data types.

[ Parent | on HN ]
Re:Using the Specification Pattern to Build a Data-Driven Ru... by quelltext on Tuesday March 24, 2020 @12:57PM (#22676301)
Don't you mean the Interpreter pattern /s
[ Parent | on HN ]