git-class | a simple git wrapper to capture output

In Prolog, there are traditionally two ways of representing a sequence of characters:

• As a list of chars, which are atoms of length 1.
• As a list of codes, which are just integers. The integers are to be interpreted as codepoints, but the convention to be applied is left unspecified. As a (eminently sane) example, in SWI-Prolog, the space of codepoints is Unicode (thus, roughly, the codepoint-integers range from 0 and 0x10FFFF).

DCGs, a notational way of writing left-to-right list processing code, are designed to perfom parsing on "lists of exploded text". Depending on preference, the lists to-be-handled can be lists of chars or lists of codes. However, the notation for char/code processing differs when writing down the constants. Does one generally write the DCG in "char style" or "code style"? Or maybe even in char/code style for portability in case of modules exporting DCG nonterminals?

• 'a': A char (as usual: single quotes indicate an atom, and they can be left out if the token starts with a lowercase letter.)
• 0'a: the code of a .
• ['a','b']: A list of char.
• [ 0'a, 0'b ]: A list of codes, namely the codes for a and b (so you can avoid typing in the actual codepoint values).
• "a" a list of codes. Traditionally, a double-quoted string is exploded into a list of codes, and this notation also works SWI-Prolog in DCG contexts, even though SWI-Prolog maps a "double-quoted string" to the special string datatype otherwise.
• `0123`. Traditonally, text within back-quotes is mapped to an atom (I think, the 95 ISO Standard just avoids being specific regarding the meaning of a back-quoted string. "It would be a valid extension of this part of ISO/IEC 13211 to define a back quoted string as denoting a character string constant."). In SWI-Prolog, text within back-quotes is exploded into a list of codes unless the flag back_quotes has been set to demand a different behaviour.

Trying to recognize "any digit" in "char style" and make its "char representation" available in C: