add explicit \date{}

git-svn-id: https://svn.r-project.org/R-dev-web/trunk@2264 c52295ea-58df-0310-926a-d16021944841

Author: maechler

howMethodsWork.tex

@@ -28,7 +28,7 @@
 
 \title{How S4 Methods Work}
 \author{John Chambers}
-
+\date{August 2006}
 \begin{document}
 \ifpdf
 \DeclareGraphicsExtensions{.pdf, .jpg, .tif}
@@ -89,8 +89,8 @@ \section{Functions, Classes, and Object-oriented Programming}
 Each method is stored within the generic function according to its \emph{signature},  which we can think of as a named list of classes, with the names corresponding to the formal arguments of the function.  So for a function with arguments \SExpression{x} and \SExpression{y} (and perhaps others):
 \begin{Example}
 \SPrompt{}signature(x= "dgCMatrix", y="dgeMatrix")
-          x           y 
-"dMatrix" "dgeMatrix" 
+          x           y
+"dMatrix" "dgeMatrix"
 \end{Example}
 In a call to this function, arguments will have corresponding classes, either the actual class or \Cq{missing} if the argument is missing.
 The closeness of the actual arguments to the  classes in the signature  determines how well the method matches the call.
@@ -272,12 +272,12 @@ \subsection*{Primitive functions}
 \begin{Example}
 \SPrompt{}getGeneric("+")
 standardGeneric for "+" defined from package "base"
-  belonging to group(s): Arith 
+  belonging to group(s): Arith
 
-function (e1, e2) 
+function (e1, e2)
 standardGeneric("+", .Primitive("+"))
 <environment: 0x2b82eb0>
-Methods may be defined for arguments: e1, e2 
+Methods may be defined for arguments: e1, e2
 \end{Example}
 The generic functions corresponding to primitives are kept in a list in the \SPackage{methods} package, and used for method dispatch and other computations, without being assigned in the ordinary way.
 So long as computations access the generic function through \SFunction{getGeneric}, most computations should be unaffected.
@@ -293,7 +293,7 @@ \subsection*{Primitive functions}
 Instead, encountering an object of primitive type for a method signals that there is no method defined for this signature.
 The internal method search returns a special reference that tells the calling code in the evaluator to go on with the original built-in definition for the function.
 Programmers do need to be careful when working with selected method definitions to be prepared for a primitive object.
-It would be possible to use a special form of 
+It would be possible to use a special form of
 
 \subsection*{Active signature}
 \label{sec:active-signature}
@@ -305,10 +305,10 @@ \subsection*{Active signature}
 \SPrompt{}getGeneric("[")
 standardGeneric for "[" defined from package "base"
 
-function (x, i, j, ..., drop) 
+function (x, i, j, ..., drop)
 standardGeneric("[", .Primitive("["))
 <environment: 0x2a2207c>
-Methods may be defined for arguments: x, i, j, drop 
+Methods may be defined for arguments: x, i, j, drop
 \end{Example}
 The argument \SExpression{drop} to the generic is only relevant for arrays; in addition, the argument \SExpression{j} is included to allow methods to depend on the class of the column index for two-way objects such as matrices or data frames.
 
@@ -412,7 +412,7 @@ \section{Earlier Versions of Method Selection}
 \end{document}
 
 
-%%% Local Variables: 
+%%% Local Variables:
 %%% mode: latex
 %%% TeX-master: t
-%%% End: 
+%%% End: