<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >component-list-child-number</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="DSSSL Library Reference" HREF="index.html"><LINK REL="UP" TITLE="Miscellaneous" HREF="r300.htm"><LINK REL="PREVIOUS" TITLE="component-list-descendant-node-list" HREF="component-descendant-list-node-list.html"><LINK REL="NEXT" TITLE="expt" HREF="expt.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >DSSSL Library Reference: Part of the Modular DocBook Stylesheet distribution</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="component-descendant-list-node-list.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="expt.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="COMPONENT-LIST-CHILD-NUMBER" ></A >component-list-child-number</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN1217" ></A ><H2 >Name</H2 >component-list-child-number -- Find child-number of a list of children within a component</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN1220" ></A ><H2 >Synopsis</H2 ><PRE CLASS="SYNOPSIS" >(component-list-child-number inputnd inputlist complist)</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1223" ></A ><H2 >Description</H2 ><P >Finds the first ancestor of <TT CLASS="LITERAL" >inputnd</TT > in <TT CLASS="LITERAL" >complist</TT > and then counts all the elements of the types in <TT CLASS="LITERAL" >inputlist</TT > from that point on and returns the number of <TT CLASS="LITERAL" >inputnd</TT >.</P ><P >If the node is not found, 0 is returned.</P ><P >WARNING: this requires walking over *all* the descendants of the ancestor node. This may be *slow*.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1232" ></A ><H2 >Author</H2 ><P >Norman Walsh, <ndw@nwalsh.com></P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1235" ></A ><H2 >Source Code</H2 ><PRE CLASS="PROGRAMLISTING" >(define (component-list-child-number inputnd inputlist complist) ;; Find child-number of a list of children within a component (let loop ((nl (component-list-descendant-node-list inputnd inputlist complist)) (num 1)) (if (node-list-empty? nl) 0 (if (node-list=? (node-list-first nl) inputnd) num (loop (node-list-rest nl) (+ num 1))))))</PRE ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="component-descendant-list-node-list.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="expt.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >component-list-descendant-node-list</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="r300.htm" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >expt</TD ></TR ></TABLE ></DIV ></BODY ></HTML >