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revision 1.48 by ttn, Wed Aug 10 14:29:00 2005 UTC revision 1.49 by rms, Thu Sep 15 13:11:24 2005 UTC
# Line 78  syntax.  @xref{Read and Print}. Line 78  syntax.  @xref{Read and Print}.
78    In most cases, an object's printed representation is also a read    In most cases, an object's printed representation is also a read
79  syntax for the object.  However, some types have no read syntax, since  syntax for the object.  However, some types have no read syntax, since
80  it does not make sense to enter objects of these types as constants in  it does not make sense to enter objects of these types as constants in
81  a Lisp program.  These objects are printed in @dfn{hash notation}: the  a Lisp program.  These objects are printed in @dfn{hash notation},
82  characters @samp{#<} followed by a descriptive string (typically the  which consists of the characters @samp{#<}, a descriptive string
83  type name followed by the name of the object), and closed with a  (typically the type name followed by the name of the object), and a
84  matching @samp{>}.  For example:  closing @samp{>}.  For example:
85    
86  @example  @example
87  (current-buffer)  (current-buffer)
# Line 621  come to refer to any structure made out Line 621  come to refer to any structure made out
621  @dfn{atoms}.  @dfn{atoms}.
622    
623  @cindex parenthesis  @cindex parenthesis
624    @cindex @samp{(@dots{})} in lists
625    The read syntax and printed representation for lists are identical, and    The read syntax and printed representation for lists are identical, and
626  consist of a left parenthesis, an arbitrary number of elements, and a  consist of a left parenthesis, an arbitrary number of elements, and a
627  right parenthesis.  Here are examples of lists:  right parenthesis.  Here are examples of lists:
# Line 706  buttercup)}, sketched in a different man Line 707  buttercup)}, sketched in a different man
707  @end group  @end group
708  @end smallexample  @end smallexample
709    
 @cindex @samp{(@dots{})} in lists  
710  @cindex @code{nil} in lists  @cindex @code{nil} in lists
711  @cindex empty list  @cindex empty list
712    A list with no elements in it is the @dfn{empty list}; it is identical    A list with no elements in it is the @dfn{empty list}; it is identical
# Line 749  two-element list: Line 749  two-element list:
749  @end group  @end group
750  @end example  @end example
751    
752    The same list represented in the first box notation looks like this:    The same list represented in the second box notation looks like this:
753    
754  @example  @example
755  @group  @group
# Line 776  two-element list: Line 776  two-element list:
776    @dfn{Dotted pair notation} is a general syntax for cons cells that    @dfn{Dotted pair notation} is a general syntax for cons cells that
777  represents the @sc{car} and @sc{cdr} explicitly.  In this syntax,  represents the @sc{car} and @sc{cdr} explicitly.  In this syntax,
778  @code{(@var{a} .@: @var{b})} stands for a cons cell whose @sc{car} is  @code{(@var{a} .@: @var{b})} stands for a cons cell whose @sc{car} is
779  the object @var{a}, and whose @sc{cdr} is the object @var{b}.  Dotted  the object @var{a} and whose @sc{cdr} is the object @var{b}.  Dotted
780  pair notation is more general than list syntax because the @sc{cdr}  pair notation is more general than list syntax because the @sc{cdr}
781  does not have to be a list.  However, it is more cumbersome in cases  does not have to be a list.  However, it is more cumbersome in cases
782  where list syntax would work.  In dotted pair notation, the list  where list syntax would work.  In dotted pair notation, the list
# Line 913  you can get the same effect with nested Line 913  you can get the same effect with nested
913  type of array has its own read syntax; see the following sections for  type of array has its own read syntax; see the following sections for
914  details.  details.
915    
916    The array type is contained in the sequence type and    The array type is a subset of the sequence type, and contains the
917  contains the string type, the vector type, the bool-vector type, and the  string type, the vector type, the bool-vector type, and the char-table
918  char-table type.  type.
919    
920  @node String Type  @node String Type
921  @subsection String Type  @subsection String Type
# Line 1166  only the first 3 bits are used: Line 1166  only the first 3 bits are used:
1166    
1167      A hash table is a very fast kind of lookup table, somewhat like an      A hash table is a very fast kind of lookup table, somewhat like an
1168  alist in that it maps keys to corresponding values, but much faster.  alist in that it maps keys to corresponding values, but much faster.
1169  Hash tables have no read syntax, and  Hash tables have no read syntax, and print using hash notation.
1170  print using hash notation.  @xref{Hash Tables}.  @xref{Hash Tables}, for functions that operate on hash tables.
1171    
1172  @example  @example
1173  (make-hash-table)  (make-hash-table)
# Line 1607  to a non-@code{nil} value.  @xref{Output Line 1607  to a non-@code{nil} value.  @xref{Output
1607    
1608  @node Type Predicates  @node Type Predicates
1609  @section Type Predicates  @section Type Predicates
 @cindex predicates  
1610  @cindex type checking  @cindex type checking
1611  @kindex wrong-type-argument  @kindex wrong-type-argument
1612    
# Line 1942  always true. Line 1941  always true.
1941  @end group  @end group
1942  @end example  @end example
1943    
1944    @cindex equality of strings
1945  Comparison of strings is case-sensitive, but does not take account of  Comparison of strings is case-sensitive, but does not take account of
1946  text properties---it compares only the characters in the strings.  For  text properties---it compares only the characters in the strings.  For
1947  technical reasons, a unibyte string and a multibyte string are  technical reasons, a unibyte string and a multibyte string are

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