<html> <head> <title>SWIG Parameter Handling</title> </head> <body> <center> <h1>SWIG Parameter Handling</h1> <p> David M. Beazley <br> dave-swig@dabeaz.com<br> January 9, 2007<br> </b> </center> <h2>Introduction</h2> This document describes the functions related to management of function parameters and parameter lists in the SWIG core. These functions are declared in <tt>Source/Swig/swigparm.h</tt>. This API is considered to be stable. <h2>Parameters</h2> The following utility functions are used to create and copy individual parameters. In their most basic form, a parameter merely contains a type, a name, and an optional default value. <p> <b><tt>Parm *NewParm(SwigType *type, const String_or_char *name)</tt></b> <blockquote> Creates a new parameter object with type <tt>type</tt> and name <tt>name</tt>. The type is stored in the attribute "type" and the name is stored in the attribute "name". </blockquote> <p> <b><tt>Parm *CopyParm(Parm *p)</tt></b> <blockquote> Copies a parameter object. All string attributes are copied in the process of making the copy. However, no complex attributes (lists, hashes, etc.) are copied. </blockquote> <h2>Parameter Lists</h2> <p> <b><tt>ParmList *CopyParmList(ParmList *p)</tt></b> <blockquote> Creates a copy of a parameter list. A parameter list is merely a linked list of parameters created by NewParm(). </blockquote> <p> <b><tt>ParmList *CopyParmListMax(ParmList *p, int count)</tt></b> <blockquote> Copies at most <tt>count</tt> parameters from the parameter list <tt>p</tt>. </blockquote> <p> <b><tt>int ParmList_len(ParmList *p)</tt></b> <blockquote> Returns the total number of parameters in a parameter list. </blockquote> <p> <b><tt>int ParmList_numrequired(ParmList *p)</tt></b> <blockquote> Returns the number of required parameters in a parameter list. This pertains to invoking a function/method in C/C++. </blockquote> <p> <b><tt>int ParmList_has_defaultargs(ParmList *p)</tt></b> <blockquote> Returns 1 if the parameter list has any default arguments. Otherwise returns 0. </blockquote> <h2>Code Generation Functions</h2> <p> <b><tt>String *ParmList_str(ParmList *p)</tt></b> <blockquote> Creates a C prototype string of the parameters, but without any default values. </blockquote> <p> <b><tt>String *ParmList_str_defaultargs(ParmList *p)</tt></b> <blockquote> Creates a C prototype string of the parameters and includes the default values (if any). </blockquote> <p> <b><tt>String *ParmList_protostr(ParmList *p)</tt></b> <blockquote> Creates a C prototype string of the parameters. </blockquote> </body> </html>
