<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; charset=utf-8"> <META content="MSHTML 6.00.6000.16825" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face="Courier New" size=2>(compose) --> error, procedure compose: no clause matching 0 arguments</FONT></DIV> <DIV><FONT face="Courier New" size=2>Why not (compose) --> #<procedure:</FONT><FONT face="Courier New" size=2>values> ?</FONT></DIV> <DIV><FONT face="Courier New" size=2></FONT> </DIV> <DIV><FONT face="Courier New" size=2>The docs of DrScheme, version 4.1.5.5-svn2may2009 [3m] say:</FONT></DIV> <DIV><FONT face="Courier New" size=2></FONT> </DIV> <DIV><TR><TD><SPAN class=schemeparen>(</SPAN><A name=(dep._((lib._scheme/base..ss)._compose))></A><A name=(def._((lib._scheme/base..ss)._compose))></A><SPAN title="Provided from: scheme/base, scheme"><SPAN class=schemesymbol><A class=schemevaluelink href="file://C:\Program Files\PLT-FULL-4.1.5.5\doc\reference\procedures.html#%28def._%28%28lib._scheme/base..ss%29._compose%29%29">compose</A></SPAN></SPAN><SPAN class=hspace> </SPAN><SPAN class=schemevariable>proc</SPAN><SPAN class=hspace> </SPAN><SPAN class=schememeta>...</SPAN><SPAN class=schemeparen>)</SPAN><SPAN class=hspace> </SPAN>→<SPAN class=hspace> </SPAN><SPAN class=schemesymbol><A class=schemevaluelink href="file://C:\Program Files\PLT-FULL-4.1.5.5\doc\reference\procedures.html#%28def._%28%28quote._%7E23%7E25kernel%29._procedure%7E3f%29%29">procedure?</A></SPAN></TD></TR><TR><TD><SPAN class=hspace> </SPAN></DIV> <DIV><SPAN class=hspace></SPAN><SPAN class=schemevariable>proc</SPAN><SPAN class=hspace> </SPAN>:<SPAN class=hspace> </SPAN><SPAN class=schemesymbol><A class=schemevaluelink href="file://C:\Program Files\PLT-FULL-4.1.5.5\doc\reference\procedures.html#%28def._%28%28quote._%7E23%7E25kernel%29._procedure%7E3f%29%29">procedure?</A></SPAN></DIV> <DIV><SPAN class=schemesymbol></SPAN> </DIV> <DIV><SPAN class=schemesymbol><FONT face="Courier New" size=2>This suggests that compose can be applied without actual arguments.</FONT></SPAN></DIV> <DIV><SPAN class=schemesymbol><FONT face="Courier New" size=2>The docs do not specify what happens in this case.</FONT></SPAN></DIV> <DIV><SPAN class=schemesymbol></SPAN> </DIV> <DIV><SPAN class=schemesymbol><FONT face="Courier New" size=2>I propose:</FONT></SPAN></DIV> <DIV><SPAN class=schemesymbol><FONT face="Courier New" size=2></FONT></SPAN> </DIV> <DIV><SPAN class=schemesymbol><FONT face="Courier New" size=2>1: adding one more case-lambda clause to the definition of compose:</FONT></SPAN></DIV> <DIV><SPAN class=schemesymbol><FONT face="Courier New" size=2>(() values)</FONT></SPAN></DIV> <DIV><SPAN class=schemesymbol><FONT face="Courier New" size=2></FONT></SPAN> </DIV> <DIV><SPAN class=schemesymbol><FONT face="Courier New" size=2>2: adding "(compose) --> procedure values" in the docs.</FONT></SPAN></DIV> <DIV><SPAN class=schemesymbol><FONT face="Courier New" size=2></FONT></SPAN></TD></TR></DIV> <DIV><FONT face="Courier New" size=2>Jos</FONT></DIV></BODY></HTML>