Trying to understand import, browse, "as" and other terminology

Question

I'm trying to understand at the lowest level exactly how Plutus/Haskell/Cabal works.

I executed the following in the repl (inside nix):

> import PlutusTx.Builtins.Internal as PTxBI

Doing this causes no error, and I see the Prelude prompt now includes "PTxBI".

Yet I cannot work with "PTxBI". I cannot browse it, get info, etc. The image shows some of my attempts (mostly to see what error messages get generated). I find the "not in scope" errors very curious.

If I enter

> :browse PlutusTx.Builtins.Internal

I do get meaningful, error-free output.

Why does the repl not recognize "PTxBI"? It obviously recognized it well enough to include it in the Prelude prompt. This feels like broken behavior.

Answer 1

1. browse: apparently you can't use the alias of an imported module when browsing

import Data.Maybe as DM
:browse Data.Maybe           ~> works
:browse DM                   ~> throws an error

2. info: according to the docs, :i gives you information about a name. The alias of a module is not a name, neither is the name of the module, i.e.

:i Data.Maybe   ~> throws an error  
:i Maybe        ~> works

3. type: according to the docs, :t gives you the type of an expression. The alias/name of a module is not an expression, i.e.

:t Data.Maybe   ~> throws an error  
:t Maybe        ~> throws an error, a type is not an expression  
:t Just         ~> works

4. let m = PTxBI 17: you need a constructor after the equal sign, not the alias of a module. You could write PTxBI.BuiltinInteger.