These functions can be used in external code with OpenMaple or define_external.

The IsMaple* functions test the specified type of the given Maple object. These functions all return TRUE (1) when the Maple DAG, s, fits the description given by the function name. If s is not of the correct type, FALSE (0) is returned.

MapleNumArgs returns the length of any Maple object.  It is most useful for computing the length of the argument expression sequence passed out to the call_external dll entry point.  An expression sequence object can be treated as a simple array with indexing starting at 1 (not 0).  For example, if args is an expression sequence and MapleNumArgs(kv,args) returns 3, then args[1], args[2], and args[3] are all Maple objects.  In the case of an external entry point, these are the arguments given during the function call.

There are several functions for determining what kind of NULL an object is. These are primarily used by automatic wrapper generation, and are not commonly be seen in hand-written code.  IsMapleUnnamedZero looks for a Maple zero object, but not a name assigned the value zero. IsMapleNULL tests for the empty expression sequence denoted by NULL in the Maple language.  IsPointerNULL tests for the C version of NULL (hardware zero), or the Maple string, "NULL".

IsMapleStop can be used with OpenMaple to detect the evaluation of the quit command.

The IsMaple...Numeric routines use the Maple type numeric definition. All other tests use the object type definition as defined by the type command. The only significant exception is IsMapleName, which returns TRUE only for NAME objects, while type(t[1], name) returns true even if it is testing a TABLEREF object.

Integer query routines, with the bit size specified in the name, test to ensure that the given Maple object, s, is a Maple integer and also that it can fit into the specified number of bits if converted to a hardware integer.

$\mathrm{with}\left(\mathrm{ExternalCalling}\right)\:$

$\mathrm{dll}≔\mathrm{ExternalLibraryName}\left(''HelpExamples''\right)\:$

$\mathrm{myrand}≔\mathrm{DefineExternal}\left(\mathrm{MyRand}\,\mathrm{dll}\right)\:$

$\mathrm{myrand}\left(100\right)$

$97$

$\mathrm{myrand}\left(\mathrm{xx}\right)$

Error, (in myrand) integer expected for 1st argument, instead got xx

The IsMapleEquation, IsMapleFraction, IsMapleLogical and IsMapleRelation commands were introduced in Maple 2018.

For more information on Maple 2018 changes, see Updates in Maple 2018.