EQ | A simple JavaScript Equalizer | Frontend Utils library

I think I may have figured out the problem. It appears that this is related to the use of conditionals in the variable setup. While the variables will be set in any valid trigger configuration, it appears that the proper values are not used during validation and that may have been causing the problem. Switching my conditional variables to first set a default value and then replace the value conditionally seems to have fixed the problem.

It would be nice if Microsoft would give a more useful error message here, something to the extent of the values not being found for a given variable, but adding defaults does seem to have fixed the problem.

In Haskell, you can use existential types to express "some unknown type of this typeclass". (In older versions of GHC, you will need a few standard extensions on.)

This sounds very like a problem that crops up in Haskell from time to time. The problem is one of garbage collection.

There are two ways that this can go. Firstly, the lazy list can be consumed as it is used, so that the amount of memory consumed is limited. Or, secondly, the lazy list can be evaluated in a way that it remains in memory all of the time, with one end of the list pinned in place because it is still being used - the garbage collector objects to this and spends a lot of time trying to deal with this situation.

Haskell can be as fast as C, but requires the calculation to be strict for this to be possible.

I don't entirely understand the code, but it appears to be recursively creating a longer and longer list, which is then evaluated. Do you have the tools to measure the amount of memory that the garbage collector is having to deal with, and how much time the garbage collector runs for?

Use a higher-rank trait bound denoted by for<'a>:

Do you need to create an expression and compile it? Unless I'm missing some nuance to this, all you need is a function that returns a Func.

With enough language features, it's possible to make a constraint that combines constraints:

you can cast it as a bool.

It took me some time to find the monad, and since it is not related to List, I figured I'd post an answer.

The expression reverse >>= (==) implies the type of reverse is m a, for some monad m, hence m a is the type [c] -> [c]. We also need isPalindromeM to have type [c] -> Bool, and the bind expression implies m b is identical to [c] -> Bool. Finally this context requires (==) :: [c] -> [c] -> Bool to have the type a -> m b.

Therefore we deduce a is [c] and b is Bool, and the monad m takes a type a and sends it to the function type [c] -> a. This suggests the monad at play is Monad ((->) [c]). defined here

If there's some moral to the story, perhaps it's "you can make a monad out of anything".

First of all, technically when you enter the GHC.Integer.Type module you leave the realm of Haskell and enter the realm of the current implementation that GHC uses, so this question is about GHC Haskell specifically.

All the primitive operations like (<#) are implemented as a recursive loop which you have found in the GHC.Prim module. From there the documentation tells us the next place to look is the primops.txt.pp file where it is listed under the name IntLtOp.

Then the documentation mentioned earlier says there are two groups of primops: in-line and out-of-line. In-line primops are resolved during the translation from STG to Cmm (which are two internal representations that GHC uses) and can be found in the GHC.StgToCmm.Prim module. And indeed the IntLtOp case is listed there and it is transformed in-line using mainly the mo_wordSLt function which depends on the platform.

This mo_wordSLt function is defined in the GHC.Cmm.MachOp module which contains to quote:

Machine-level primops; ones which we can reasonably delegate to the native code generators to handle.

The mo_wordSLt function produces the MO_S_Lt constructor of the MachOp data type. So we can look further into a native code generator to see how that is translated into low-level instructions. There is quite a bit of choice in platforms: SPARC, AArch64, LLVM, C, PPC, and X86 (I found all these with the search function on GitLab).

X86 is the most popular platform, so I will continue there. The implementation uses a condIntReg helper function, which is defined as follows: