Data::Dump::Trace(3pm)

1Data::Dump::Trace(3)  User Contributed Perl Documentation Data::Dump::Trace(3)
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NAME

6       Data::Dump::Trace - Helpers to trace function and method calls
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SYNOPSIS

9         use Data::Dump::Trace qw(autowrap mcall);
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11         autowrap("LWP::UserAgent" => "ua", "HTTP::Response" => "res");
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13         use LWP::UserAgent;
14         $ua = mcall(LWP::UserAgent => "new");      # instead of LWP::UserAgent->new;
15         $ua->get("http://www.example.com")->dump;
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DESCRIPTION

18       The following functions are provided:
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20       autowrap( $class )
21       autowrap( $class => $prefix )
22       autowrap( $class1 => $prefix1,  $class2 => $prefix2, ... )
23       autowrap( $class1 => \%info1, $class2 => \%info2, ... )
24           Register classes whose objects are automatically wrapped when
25           returned by one of the call functions below.  If $prefix is
26           provided it will be used as to name the objects.
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28           Alternative is to pass an %info hash for each class.  The
29           recognized keys are:
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31           prefix => $string
32               The prefix string used to name objects of this type.
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34           proto => \%hash
35               A hash of prototypes to use for the methods when an object is
36               wrapped.
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38       wrap( name => $str, func => \&func, proto => $proto )
39       wrap( name => $str, obj => $obj, proto => \%hash )
40           Returns a wrapped function or object.  When a wrapped function is
41           invoked then a trace is printed after the underlying function has
42           returned.  When a method on a wrapped object is invoked then a
43           trace is printed after the methods on the underlying objects has
44           returned.
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46           See "Prototypes" for description of the "proto" argument.
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48       call( $name, \&func, $proto, @ARGS )
49           Calls the given function with the given arguments.  The trace will
50           use $name as the name of the function.
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52           See "Prototypes" for description of the $proto argument.
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54       mcall( $class, $method, $proto, @ARGS )
55       mcall( $object, $method, $proto, @ARGS )
56           Calls the given method with the given arguments.
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58           See "Prototypes" for description of the $proto argument.
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60       trace( $symbol, $prototype )
61           Replaces the function given by $symbol with a wrapped function.
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63   Prototypes
64       Note: The prototype string syntax described here is experimental and
65       likely to change in revisions of this interface.
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67       The $proto argument to call() and mcall() can optionally provide a
68       prototype for the function call.  This give the tracer hints about how
69       to best format the argument lists and if there are in/out or out
70       arguments.  The general form for the prototype string is:
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72          <arguments> = <return_value>
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74       The default prototype is "@ = @"; list of values as input and list of
75       values as output.
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77       The value '%' can be used for both arguments and return value to say
78       that key/value pair style lists are used.
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80       Alternatively, individual positional arguments can be listed each
81       represented by a letter:
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83       "i" input argument
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85       "o" output argument
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87       "O" both input and output argument
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89       If the return value prototype has "!" appended, then it signals that
90       this function sets errno ($!) when it returns a false value.  The trace
91       will display the current value of errno in that case.
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93       If the return value prototype looks like a variable name (with "$"
94       prefix), and the function returns a blessed object, then the variable
95       name will be used as prefix and the returned object automatically
96       traced.
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NAME

SYNOPSIS

DESCRIPTION

SEE ALSO