This allows to capture the symbol inside an expression when available. If the expression corresponds to a recognised metasymbol, then it will be that symbol. Otherwise it will be the string corresponding to the original code, but where the symbol names will be replaces for the corresponding parts of code.
This allows to capture the symbol inside an expression when available. If the expression corresponds to a recognised metasymbol, then it will be that symbol. Otherwise it will be the string corresponding to the original code, but where the symbol names will be replaces for the corresponding parts of code.