[crdrost]

Haskell is somewhat similar, too! I think some of this comes from C.

The goal of a Haskell compiler is to take your code and spit out an executable. That executable is in fact the value named “Main.main,” which must be of the in-Haskell type (translating to English) “a program which produces nothing.” In the source code you are constantly juggling values of type “a program which produces ____” and linking them together with the in-built methods, to get to this point, and the compiler just takes one of these things, based on a naming convention, and spits it out to the filesystem. And I think it got this convention because it was really handy how C similarly used a well-known name to specify its entry point into the source file.

The difference is then that Pointless does not have a type restriction on what “main” can be and instead of “saving to the filesystem” it dumps to stdout. Presumably with the right sort of metaprogramming attitude one could do what Haskell does in Pointless, maybe—when output is a program it could maybe spit out a compiled executable to stdout and you would redirect it to a disk location and set its executable permission manually.

[lgas]

Actually `main` in Haskell can be an IO action returning any type, eg this is a perfectly valid main:

    main :: IO Int
    main = print "10" >> pure 10

the return value is just ignored when it's actually invoked as an executable (but can be used if invoked eg. in the repl, or if main is also called from somewhere deeper in the code).