gup | simple bash function to help you go | Command Line Interface library

I want to replace anything other than character, spaces and number only in end with empty string or in other words: we replace any number or spaces comes in-starting or in-middle of the string replace with empty string.

Example

I am creating a huffman class that can encode and decode text but I am having trouble with my decode method. My encoding method works fine and my decoding method works for smaller amounts of text. But when I try to decode large amounts of text I get a maximum recursion depth error and am not sure how to fix it. The class takes in a dictionary with characters and their frequencies and then turns them into nodes and builds the tree. After building the tree it puts the characters and their bitcode into another dictionary to be used for encoding and decoding.

I don't know why but getting the TypeError: unsupported operand type(s) for +=: 'method' and 'int'

What does triple colon (:::) in a data type mean in Haskell?

For example: data Term = Var ID | Atom String | Nil | Term:::Term

Which is found in this paper https://gup.ub.gu.se/file/207634

How would it be used?

For example, I can do foo = Var "hello" but I don't know what use Term:::Term would be.

I'm currently using something like this:

I am building the Typesafe formbuilder, it should produce a chain of excecutable functions that look like this: FormBuilder.Entity(Pair(DefaultStudent, {}), q => q.Select('name', 'gender') .Children('courses', q => q.Select('code'))

It all works right know, but I get a type error on the q.select('code') part stating that type entity is not compatible with other types.

This the code used to generate the form :