1Language::Prolog::TypesU:s:eCronCvoenrttreirb(u3t)ed PerLlanDgoucaugmee:n:tPartoiloong::Types::Converter(3)
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6 Language::Prolog::Types::Converter - Converts from Perl objects to
7 Prolog terms
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10 package MyModule;
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12 use Language::Prolog::Types::Converter;
13 our @ISA=qw(Language::Prolog::Types::Converter);
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15 sub hash2prolog {
16 ...
17 }
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19 sub scalar2prolog {
20 ...
21 }
22
23 etc.
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26 This module implements a class to be used from interfaces to Prolog
27 systems (SWI-Prolog, XSB, etc.) to transform complex Perl data types to
28 Prolog types.
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31 You should use this module if you want to change the default
32 conversions performed when passing data between Perl and Prolog.
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34 METHODS
35 "Language::Prolog::Types::Converter-">new()>
36 returns a new converter object.
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38 "$self->pass_as_opaque($class1, $class2, ...)"
39 instruct the converter object to pass objects belonging to classes
40 class1, class2, etc. to Prolog as opaque objects. The Prolog
41 interpreter will not touch them but just use them in Perl call
42 backs.
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44 To override the default conversions performed, you have to redefine the
45 method "perl_ref2prolog".
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47 If you make your converter class inherit
48 Language::Prolog::Types::Converter, you can change conversions only for
49 selected types overriding those methods:
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51 "$conv->hash2prolog($hash_ref)"
52 converts a Perl hash reference to a Prolog term.
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54 It creates a list of functors '=>/2' with the key/value pairs as
55 arguments:
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57 [ '=>'(key0, value0), '=>'(key1, value1), ... ]
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59 "$conv->scalar2prolog($scalar_ref)"
60 converts a Perl scalar reference to a Prolog term.
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62 "$conv->glob2prolog($glob_ref)"
63 converts a Perl glob reference to a Prolog term.
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65 "$conv->code2prolog($code_ref)"
66 converts a Perl sub reference to a Prolog term.
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68 "$conv->object2prolog($object_ref)"
69 converts any other Perl object to a Prolog term.
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71 Default implementation looks for a method called
72 "convert2prolog_term" in the object class.
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74 If this fails, it reverts to dump the internal representation of
75 the object as the functor:
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77 perl_object(class, state)
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79 "state" is the conversion of the perl datatype used to represent
80 the object (array, hash, scalar, glob or sub).
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82 EXPORT
83 None by default. This module has an OO interface.
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86 Language::Prolog::Types, Language::XSB::Base,
87 Language::Prolog::Yaswi::Low.
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90 Salvador Fandiño, <sfandino@yahoo.com>
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93 Copyright 2002 by Salvador Fandiño
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95 This library is free software; you can redistribute it and/or modify it
96 under the same terms as Perl itself.
97
99 Hey! The above document had some coding errors, which are explained
100 below:
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102 Around line 210:
103 Non-ASCII character seen before =encoding in 'Fandiño,'. Assuming
104 CP1252
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108perl v5.28.1 2006-05-L0a8nguage::Prolog::Types::Converter(3)