latex - Redefining Commands with Parameters using \newenvironment -

Compliance with this question:

How to redefine one Uses the macro parameter using (or defines \ def ? I'm getting the invalid parameter definition \ foo error because I need a custom delimiter , So I can not use \ newcommand or \ renewcommand .

A normal form of my code looks like this:

  \ newenvironment {foo} {% ... Spacing content and counter defaults ... \ Diff \ fooitem # 1. # 2 \ endfooitem {% ... stuff ...} \ def \ endfooitem {endfoo}} {... after content (spacing) ...}  

This should be possible. Now I am using plain-tex definitions (as I have mentioned in the above question), but I actually have a latex system .

Let's # for each nested definition Programming will be doubled. Internally, calling a \ newcommand or \ newenvironment \ def

  \ newenvironment {foo} {% ... \ def \ fooitem ## 1 ## 2 \ endfooitem {% ...  

besides , The way to do that you are trying to do; There is no pure-latex method to define a macro with delimited logic.