| GetArgType | Function (Macro)

args.h

unsigned char GetArgType (CESI ap);

Returns the type of the current argument.

GetArgType returns a one-byte value which determines the type of the current argument (pointed to by ap). There are many types of arguments: strings, integers (positive or negative), fractions, floats, symbols, various algebraic expressions, lists, matrices, etc. The enum Tags defines a lot of constants: the most commonly used in argument lists are STR_TAG, POSINT_TAG, NEGINT_TAG, FLOAT_TAG, POSFRAC_TAG, ENDFRAC_TAG, COMPLEX_TAG, LIST_TAG and END_TAG. They represent respectively a string, a positive integer, a negative integer, a floating point value, a positive fraction, a negative fraction, a complex number, a beginning of the list structure and an end-of-list marker (which also has meaning "no more arguments"). Any values except these need to be regarded as "an expression": you need to handle them "by hand" (of course, if you know how). See InitArgPtr for an example of usage.
Note: You can use SkipArg to bypass the argument which you don't know how to handle (or, which you don't want to handle for any reason).