1AutoLoader(3)         User Contributed Perl Documentation        AutoLoader(3)
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NAME

6       PDL::AutoLoader - MatLab style AutoLoader for PDL
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SYNOPSIS

9        use PDL::AutoLoader;
10        $a = func1(...);   # Load file func1.pdl
11        $b = func2(...);   # Load file func2.pdl
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13        $PDL::AutoLoader::Rescan = 1; # Enable re-scanning
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DESCRIPTION

16       This module implements a MatLab style AutoLoader for PDL. If a unknown
17       function 'func()' is called then a file 'func.pdl' is searched for and
18       if found is read in to define 'func()' which is then executed.
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20       Files are seached for using the directories in seach path @PDLLIB,
21       which is initialised from the shell environment variable "PDLLIB" which
22       is a colon seperated list of directories.
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24       e.g. in csh
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26        setenv PDLLIB "/home/kgb/pdllib:/local/pdllib"
27
28       Note this is kept seperate from "PERL5LIB" just in case.
29
30       As an added bonus, you can use a leading '+' on a directory name to
31       search not just that directory but the entire directory tree under it
32       (excluding symlinks).  The subdirs are determined by explicit search,
33       and searches occur at startup and again each time you change the number
34       of elements in @PDLLIB.
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36       For example,
37         setenv PDLLIB "+~kgb/PDL"
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39       will search /home/kgb/PDL and all its subdirectories for .pdl files.
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41   AUTO-SCANNING
42       The variable $PDL::AutoLoader::Rescan controls whether files are
43       automatically re-scanned for changes at the "perldl" command line.
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45       If "$PDL::AutoLoader::Rescan == 1" and the file is changed then the new
46       definition is reloaded auto-matically before executing the "perldl"
47       command line. Which means in practice you can edit files, save changes
48       and have "perldl" see the changes automatically.
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50       The default is '0' - i.e. to have this feature disabled.
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52       As this feature is only pertinent to the "perldl" shell it imposes no
53       overhead on PDL scripts. Yes Bob you can have your cake and eat it too!
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55       Note: files are only re-evaled if they are determined to have been
56       changed according to their date/time stamp.
57
58       No doubt this interface could be improved upon some more. :-)
59
60   Sample file:
61        sub foo { # file 'foo.pdl' - define the 'foo' function
62          my $x=shift;
63          return sqrt($x**2 + $x**3 + 2);
64        }
65        1; # File returns true (i.e. loaded successfully)
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AUTHOR

68       Copyright(C) 1997 Karl Glazebrook (kgb@aaoepp.aao.gov.au); several
69       extensions by Craig DeForest (deforest@boulder.swri.edu) All rights
70       reserved. There is no warranty. You are allowed to redistribute this
71       software / documentation under certain conditions. For details, see the
72       file COPYING in the PDL distribution. If this file is separated from
73       the PDL distribution, the copyright notice should be included in the
74       file.
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BUGS

77       No doubt this interface could be improved upon some more. :-)
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79       Will probably be quite slow if "$PDL::AutoLoader::Rescan == 1" and
80       thousands of functions have been autoloaded.
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82       There could be a race condition in which the file changes while the
83       internal autoloader code is being executed but it should be harmless.
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85       Probably has not been tested enough!
86
87   PDL::AutoLoader::expand_path
88       Expand a compactified path into a dir list
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90       You supply a pathlist and leading '+' and '~' characters get expanded
91       into full directories.  Normally you don't want to use this -- it's
92       internal to the autoloader -- but some utilities, like the online
93       documentation searcher, need to be able to use it.
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97perl v5.12.3                      2009-10-17                     AutoLoader(3)
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