Data::Dump::Trace - Helpers to trace function and method calls
use Data::Dump::Trace qw(autowrap mcall);
autowrap("LWP::UserAgent" => "ua", "HTTP::Response" => "res");
use LWP::UserAgent;
$ua = mcall(LWP::UserAgent => "new"); # instead of LWP::UserAgent->new;
$ua->get("http://www.example.com";)->dump;
The following functions are provided:
- autowrap( $class )
-
- autowrap( $class => $prefix )autowrap( $class => $prefix )
-
- autowrap( $class1 => $prefix1, $class2 => $prefix2, ... )autowrap( $class1 => $prefix1, $class2 => $prefix2, ... )
-
- autowrap( $class1 => \%info1, $class2 => \%info2, ... )autowrap( $class1 => \%info1, $class2 => \%info2, ... )
-
Register classes whose objects are automatically wrapped when
returned by one of the call functions below. If $prefix is provided
it will be used as to name the objects.
Alternative is to pass an %info hash for each class. The recognized keys are:
- prefix => $string
-
The prefix string used to name objects of this type.
- proto => \%hash
-
A hash of prototypes to use for the methods when an object is wrapped.
- wrap( name => $str, func => \&func, proto => $proto )
-
- wrap( name => $str, obj => $obj, proto => \%hash )wrap( name => $str, obj => $obj, proto => \%hash )
-
Returns a wrapped function or object. When a wrapped function is
invoked then a trace is printed after the underlying function has returned.
When a method on a wrapped object is invoked then a trace is printed
after the methods on the underlying objects has returned.
See Prototypes for description of the proto argument.
- call( $name, \&func, $proto, @ARGS )
-
Calls the given function with the given arguments. The trace will use
$name as the name of the function.
See Prototypes for description of the $proto argument.
- mcall( $class, $method, $proto, @ARGS )
-
- mcall( $object, $method, $proto, @ARGS )mcall( $object, $method, $proto, @ARGS )
-
Calls the given method with the given arguments.
See Prototypes for description of the $proto argument.
- trace( $symbol, $prototype )
-
Replaces the function given by $symbol with a wrapped function.
Note: The prototype string syntax described here is experimental and
likely to change in revisions of this interface.
The $proto argument to call() and mcall() can optionally provide a
prototype for the function call. This give the tracer hints about how
to best format the argument lists and if there are in/out or out
arguments. The general form for the prototype string is:
<arguments> = <return_value>
The default prototype is ``@ = @''; list of values as input and list of
values as output.
The value '%' can be used for both arguments and return value to say
that key/value pair style lists are used.
Alternatively, individual positional arguments can be listed each
represented by a letter:
- i
-
input argument
- o
-
output argument
- O
-
both input and output argument
If the return value prototype has ! appended, then it signals that
this function sets errno ($!) when it returns a false value. The
trace will display the current value of errno in that case.
If the return value prototype looks like a variable name (with $
prefix), and the function returns a blessed object, then the variable
name will be used as prefix and the returned object automatically
traced.
the Data::Dump manpage
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