I love when that happens!

[honey the codewitch]

I was making a state removal method that would turn a state machine into a regular expression. In the process I needed to do a subtask, to wit, I needed to set up a quick and dirty finite automaton engine to hold the states. Rather than make a bunch of objects/states that point to other objects/states using dictionaries, I simply stored all the dictionary transitions as a single tuple (int from, int to, string input) in a flat list. The result is smaller, and allows me to do complicated queries on the relationships between the states (now represented as simple integers) very simply. In fact, the result is so good, I may be able to rewrite a more compact and efficient state engine using this technique. And it was originally just intended to be "just enough of a thing" to be scaffolding for my overarching algorithm to work with. I'm elated. Even if the overarching algorithm doesn't work, it means far more compact and efficient code potentially in terms of the finite automata code it works with. :-D

Real programmers use butterflies

[PIEBALDconsult]

That reminds me of a third-party product a colleague was using. It didn't support proper Order-of-Operations. I said, "it's wrong", and he said, "but it's faaaasssst!"

[Richard Andrew x64]

You're a real innovator!

The difficult we do right away... ...the impossible takes slightly longer.

[honey the codewitch]

Sometimes it doesn't have to be completely right to work for a situation. Honestly I respect code that does just enough to do the job for a particular application - very efficiently. It's to my mind, one of the higher achievements in code such that if you can pull it off regularly you are way more clever than I. I have to respect it. :)

Real programmers use butterflies

[honey the codewitch]

Accidentally, so. I wish it was repeatable, but when I stumble on something, I'll take it. :)

Real programmers use butterflies

[Nelek]

honey the codewitch wrote:

Accidentally, so.

Penicillin was accidental too ;)

M.D.V. ;) If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about? Help me to understand what I'm saying, and I'll explain it better to you Rating helpful answers is nice, but saying thanks can be even nicer.

[jschell]

honey the codewitch wrote:

turn a state machine into a regular expression

That phrase is a bit odd. The way regular expressions work, depending on the match expression, is to create a state machine (and perhaps even more than one.)

[honey the codewitch]

This is doing the reverse of that.

Real programmers use butterflies

[englebart]

I like the state machine setup that is basically an abstract/pure virtual super class where each possible input is a method that returns the next state. Each state is a concrete class that must implement all of the input methods. It would likely take up more memory with vtables than your approach, but I like that it makes the introduction of a new input a compile time check on all of the states. Same if you add a new state; you have to define transitions for every input. I prefer compile time checks, but I work on a memory hog of a system where we have that luxury.😊

[honey the codewitch]

If you take a look at Reggie: A Non-Backtracking Streaming Regular Expression Code Generator[^] you'll see that since the state machines end up compiled, the input states are about as checked as they're going to get. In this way you dictate the state machine specs, it then creates an in memory digraph of the states, which it then does some transformations on before compiling into code, at which point *everything* is compiled - in this case into goto tables - one label for each state. Although it can also generate a table/array based matcher Because of how that works, your solution actually doesn't actually fit that particular application (and this is how i most often use them). Because it goes spec->state-machine->code, not spec->coded-state-machine At least if I understand you.

Real programmers use butterflies

[jschell]

Yes but just want to be clear that although you are using a regular expression it will in fact end up using a state machine to implement that regular expression.

[honey the codewitch]

Yes, but specifically I'm talking about taking that state machine and turning it back into a regular expression.

Real programmers use butterflies