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```{index} single: TAP::Parser
```

# TAP::Parser

Parse [TAP](https://metacpan.org/pod/Test::Harness::TAP) output

## VERSION

Version 3.52

## SYNOPSIS

```perl
use TAP::Parser;

my $parser = TAP::Parser->new( { source => $source } );

while ( my $result = $parser->next ) {
    print $result->as_string;
}
```

## DESCRIPTION

`TAP::Parser` is designed to produce a proper parse of TAP output. For
an example of how to run tests through this module, see the simple
harnesses `examples/`.

There's a wiki dedicated to the Test Anything Protocol:

[http://testanything.org](http://testanything.org)

It includes the TAP::Parser Cookbook:

[http://testanything.org/testing-with-tap/perl/tap::parser-cookbook.html](http://testanything.org/testing-with-tap/perl/tap::parser-cookbook.html)

## METHODS

### Class Methods

#### `new`

```perl
my $parser = TAP::Parser->new(\%args);
```

Returns a new `TAP::Parser` object.

The arguments should be a hashref with _one_ of the following keys:

- `source`

    _CHANGED in 3.18_

    This is the preferred method of passing input to the constructor.

    The `source` is used to create a [TAP::Parser::Source](Parser/Source.md) that is passed to the
    "iterator\_factory\_class" which in turn figures out how to handle the source and
    creates a <TAP::Parser::Iterator> for it.  The iterator is used by the parser to
    read in the TAP stream.

    To configure the _IteratorFactory_ use the `sources` parameter below.

    Note that `source`, `tap` and `exec` are _mutually exclusive_.

- `tap`

    _CHANGED in 3.18_

    The value should be the complete TAP output.

    The _tap_ is used to create a [TAP::Parser::Source](Parser/Source.md) that is passed to the
    "iterator\_factory\_class" which in turn figures out how to handle the source and
    creates a <TAP::Parser::Iterator> for it.  The iterator is used by the parser to
    read in the TAP stream.

    To configure the _IteratorFactory_ use the `sources` parameter below.

    Note that `source`, `tap` and `exec` are _mutually exclusive_.

- `exec`

    Must be passed an array reference.

    The _exec_ array ref is used to create a [TAP::Parser::Source](Parser/Source.md) that is passed
    to the "iterator\_factory\_class" which in turn figures out how to handle the
    source and creates a <TAP::Parser::Iterator> for it.  The iterator is used by
    the parser to read in the TAP stream.

    By default the [TAP::Parser::SourceHandler::Executable](Parser/SourceHandler/Executable.md) class will create a
    [TAP::Parser::Iterator::Process](Parser/Iterator/Process.md) object to handle the source.  This passes the
    array reference strings as command arguments to [IPC::Open3::open3](../IPC/Open3.md):

    ```perl
    exec => [ '/usr/bin/ruby', 't/my_test.rb' ]
    ```

    If any `test_args` are given they will be appended to the end of the command
    argument list.

    To configure the _IteratorFactory_ use the `sources` parameter below.

    Note that `source`, `tap` and `exec` are _mutually exclusive_.

The following keys are optional.

- `sources`

    _NEW to 3.18_.

    If set, `sources` must be a hashref containing the names of the
    [TAP::Parser::SourceHandler](Parser/SourceHandler.md)s to load and/or configure.  The values are a
    hash of configuration that will be accessible to the source handlers via
    ["config\_for" in TAP::Parser::Source](Parser/Source.md).

    For example:

    ```perl
    sources => {
      Perl => { exec => '/path/to/custom/perl' },
      File => { extensions => [ '.tap', '.txt' ] },
      MyCustom => { some => 'config' },
    }
    ```

    This will cause `TAP::Parser` to pass custom configuration to two of the built-
    in source handlers - [TAP::Parser::SourceHandler::Perl](Parser/SourceHandler/Perl.md),
    [TAP::Parser::SourceHandler::File](Parser/SourceHandler/File.md) - and attempt to load the `MyCustom`
    class.  See ["load\_handlers" in TAP::Parser::IteratorFactory](Parser/IteratorFactory.md) for more detail.

    The `sources` parameter affects how `source`, `tap` and `exec` parameters
    are handled.

    See [TAP::Parser::IteratorFactory](Parser/IteratorFactory.md), [TAP::Parser::SourceHandler](Parser/SourceHandler.md) and subclasses for
    more details.

- `callback`

    If present, each callback corresponding to a given result type will be called
    with the result as the argument if the `run` method is used:

    ```perl
    my %callbacks = (
        test    => \&test_callback,
        plan    => \&plan_callback,
        comment => \&comment_callback,
        bailout => \&bailout_callback,
        unknown => \&unknown_callback,
    );

    my $aggregator = TAP::Parser::Aggregator->new;
    for my $file ( @test_files ) {
        my $parser = TAP::Parser->new(
            {
                source    => $file,
                callbacks => \%callbacks,
            }
        );
        $parser->run;
        $aggregator->add( $file, $parser );
    }
    ```

- `switches`

    If using a Perl file as a source, optional switches may be passed which will
    be used when invoking the perl executable.

    ```perl
    my $parser = TAP::Parser->new( {
        source   => $test_file,
        switches => [ '-Ilib' ],
    } );
    ```

- `test_args`

    Used in conjunction with the `source` and `exec` option to supply a reference
    to an `@ARGV` style array of arguments to pass to the test program.

- `spool`

    If passed a filehandle will write a copy of all parsed TAP to that handle.

- `merge`

    If false, STDERR is not captured (though it is 'relayed' to keep it
    somewhat synchronized with STDOUT.)

    If true, STDERR and STDOUT are the same filehandle.  This may cause
    breakage if STDERR contains anything resembling TAP format, but does
    allow exact synchronization.

    Subtleties of this behavior may be platform-dependent and may change in
    the future.

- `grammar_class`

    This option was introduced to let you easily customize which _grammar_ class
    the parser should use.  It defaults to [TAP::Parser::Grammar](Parser/Grammar.md).

    See also "make\_grammar".

- `result_factory_class`

    This option was introduced to let you easily customize which _result_
    factory class the parser should use.  It defaults to
    [TAP::Parser::ResultFactory](Parser/ResultFactory.md).

    See also "make\_result".

- `iterator_factory_class`

    _CHANGED in 3.18_

    This option was introduced to let you easily customize which _iterator_
    factory class the parser should use.  It defaults to
    [TAP::Parser::IteratorFactory](Parser/IteratorFactory.md).

### Instance Methods

#### `next`

```perl
my $parser = TAP::Parser->new( { source => $file } );
while ( my $result = $parser->next ) {
    print $result->as_string, "\n";
}
```

This method returns the results of the parsing, one result at a time.  Note
that it is destructive.  You can't rewind and examine previous results.

If callbacks are used, they will be issued before this call returns.

Each result returned is a subclass of [TAP::Parser::Result](Parser/Result.md).  See that
module and related classes for more information on how to use them.

#### `run`

```perl
$parser->run;
```

This method merely runs the parser and parses all of the TAP.

#### `make_grammar`

Make a new [TAP::Parser::Grammar](Parser/Grammar.md) object and return it.  Passes through any
arguments given.

The `grammar_class` can be customized, as described in "new".

#### `make_result`

Make a new [TAP::Parser::Result](Parser/Result.md) object using the parser's
[TAP::Parser::ResultFactory](Parser/ResultFactory.md), and return it.  Passes through any arguments
given.

The `result_factory_class` can be customized, as described in "new".

#### `make_iterator_factory`

_NEW to 3.18_.

Make a new [TAP::Parser::IteratorFactory](Parser/IteratorFactory.md) object and return it.  Passes through
any arguments given.

`iterator_factory_class` can be customized, as described in "new".

## INDIVIDUAL RESULTS

If you've read this far in the docs, you've seen this:

```perl
while ( my $result = $parser->next ) {
    print $result->as_string;
}
```

Each result returned is a [TAP::Parser::Result](Parser/Result.md) subclass, referred to as
_result types_.

### Result types

Basically, you fetch individual results from the TAP.  The six types, with
examples of each, are as follows:

- Version

    ```text
    TAP version 12
    ```

- Plan

    ```text
    1..42
    ```

- Pragma

    ```text
    pragma +strict
    ```

- Test

    ```text
    ok 3 - We should start with some foobar!
    ```

- Comment

    ```perl
    # Hope we don't use up the foobar.
    ```

- Bailout

    ```text
    Bail out!  We ran out of foobar!
    ```

- Unknown

    ```text
    ... yo, this ain't TAP! ...
    ```

Each result fetched is a result object of a different type.  There are common
methods to each result object and different types may have methods unique to
their type.  Sometimes a type method may be overridden in a subclass, but its
use is guaranteed to be identical.

### Common type methods

#### `type`

Returns the type of result, such as `comment` or `test`.

#### `as_string`

Prints a string representation of the token.  This might not be the exact
output, however.  Tests will have test numbers added if not present, TODO and
SKIP directives will be capitalized and, in general, things will be cleaned
up.  If you need the original text for the token, see the `raw` method.

#### `raw`

Returns the original line of text which was parsed.

#### `is_plan`

Indicates whether or not this is the test plan line.

#### `is_test`

Indicates whether or not this is a test line.

#### `is_comment`

Indicates whether or not this is a comment. Comments will generally only
appear in the TAP stream if STDERR is merged to STDOUT. See the
`merge` option.

#### `is_bailout`

Indicates whether or not this is bailout line.

#### `is_yaml`

Indicates whether or not the current item is a YAML block.

#### `is_unknown`

Indicates whether or not the current line could be parsed.

#### `is_ok`

```perl
if ( $result->is_ok ) { ... }
```

Reports whether or not a given result has passed.  Anything which is **not** a
test result returns true.  This is merely provided as a convenient shortcut
which allows you to do this:

```perl
my $parser = TAP::Parser->new( { source => $source } );
while ( my $result = $parser->next ) {
    # only print failing results
    print $result->as_string unless $result->is_ok;
}
```

### `plan` methods

```perl
if ( $result->is_plan ) { ... }
```

If the above evaluates as true, the following methods will be available on the
`$result` object.

#### `plan`

```perl
if ( $result->is_plan ) {
   print $result->plan;
}
```

This is merely a synonym for `as_string`.

#### `directive`

```perl
my $directive = $result->directive;
```

If a SKIP directive is included with the plan, this method will return it.

```text
1..0 # SKIP: why bother?
```

#### `explanation`

```perl
my $explanation = $result->explanation;
```

If a SKIP directive was included with the plan, this method will return the
explanation, if any.

### `pragma` methods

```perl
if ( $result->is_pragma ) { ... }
```

If the above evaluates as true, the following methods will be available on the
`$result` object.

#### `pragmas`

Returns a list of pragmas each of which is a + or - followed by the
pragma name.

### `comment` methods

```perl
if ( $result->is_comment ) { ... }
```

If the above evaluates as true, the following methods will be available on the
`$result` object.

#### `comment`

```perl
if ( $result->is_comment ) {
    my $comment = $result->comment;
    print "I have something to say:  $comment";
}
```

### `bailout` methods

```perl
if ( $result->is_bailout ) { ... }
```

If the above evaluates as true, the following methods will be available on the
`$result` object.

#### `explanation`

```perl
if ( $result->is_bailout ) {
    my $explanation = $result->explanation;
    print "We bailed out because ($explanation)";
}
```

If, and only if, a token is a bailout token, you can get an "explanation" via
this method.  The explanation is the text after the mystical "Bail out!" words
which appear in the tap output.

### `unknown` methods

```perl
if ( $result->is_unknown ) { ... }
```

There are no unique methods for unknown results.

### `test` methods

```perl
if ( $result->is_test ) { ... }
```

If the above evaluates as true, the following methods will be available on the
`$result` object.

#### `ok`

```perl
my $ok = $result->ok;
```

Returns the literal text of the `ok` or `not ok` status.

#### `number`

```perl
my $test_number = $result->number;
```

Returns the number of the test, even if the original TAP output did not supply
that number.

#### `description`

```perl
my $description = $result->description;
```

Returns the description of the test, if any.  This is the portion after the
test number but before the directive.

#### `directive`

```perl
my $directive = $result->directive;
```

Returns either `TODO` or `SKIP` if either directive was present for a test
line.

#### `explanation`

```perl
my $explanation = $result->explanation;
```

If a test had either a `TODO` or `SKIP` directive, this method will return
the accompanying explanation, if present.

```text
not ok 17 - 'Pigs can fly' # TODO not enough acid
```

For the above line, the explanation is _not enough acid_.

#### `is_ok`

```perl
if ( $result->is_ok ) { ... }
```

Returns a boolean value indicating whether or not the test passed.  Remember
that for TODO tests, the test always passes.

**Note:**  this was formerly `passed`.  The latter method is deprecated and
will issue a warning.

#### `is_actual_ok`

```perl
if ( $result->is_actual_ok ) { ... }
```

Returns a boolean value indicating whether or not the test passed, regardless
of its TODO status.

**Note:**  this was formerly `actual_passed`.  The latter method is deprecated
and will issue a warning.

#### `is_unplanned`

```perl
if ( $test->is_unplanned ) { ... }
```

If a test number is greater than the number of planned tests, this method will
return true.  Unplanned tests will _always_ return false for `is_ok`,
regardless of whether or not the test `has_todo` (see
[TAP::Parser::Result::Test](Parser/Result/Test.md) for more information about this).

#### `has_skip`

```perl
if ( $result->has_skip ) { ... }
```

Returns a boolean value indicating whether or not this test had a SKIP
directive.

#### `has_todo`

```perl
if ( $result->has_todo ) { ... }
```

Returns a boolean value indicating whether or not this test had a TODO
directive.

Note that TODO tests _always_ pass.  If you need to know whether or not
they really passed, check the `is_actual_ok` method.

#### `in_todo`

```perl
if ( $parser->in_todo ) { ... }
```

True while the most recent result was a TODO. Becomes true before the
TODO result is returned and stays true until just before the next non-
TODO test is returned.

## TOTAL RESULTS

After parsing the TAP, there are many methods available to let you dig through
the results and determine what is meaningful to you.

### Individual Results

These results refer to individual tests which are run.

#### `passed`

```perl
my @passed = $parser->passed; # the test numbers which passed
my $passed = $parser->passed; # the number of tests which passed
```

This method lets you know which (or how many) tests passed.  If a test failed
but had a TODO directive, it will be counted as a passed test.

#### `failed`

```perl
my @failed = $parser->failed; # the test numbers which failed
my $failed = $parser->failed; # the number of tests which failed
```

This method lets you know which (or how many) tests failed.  If a test passed
but had a TODO directive, it will **NOT** be counted as a failed test.

#### `actual_passed`

```perl
## the test numbers which actually passed
my @actual_passed = $parser->actual_passed;

## the number of tests which actually passed
my $actual_passed = $parser->actual_passed;
```

This method lets you know which (or how many) tests actually passed,
regardless of whether or not a TODO directive was found.

#### `actual_ok`

This method is a synonym for `actual_passed`.

#### `actual_failed`

```perl
## the test numbers which actually failed
my @actual_failed = $parser->actual_failed;

## the number of tests which actually failed
my $actual_failed = $parser->actual_failed;
```

This method lets you know which (or how many) tests actually failed,
regardless of whether or not a TODO directive was found.

#### `todo`

```perl
my @todo = $parser->todo; # the test numbers with todo directives
my $todo = $parser->todo; # the number of tests with todo directives
```

This method lets you know which (or how many) tests had TODO directives.

#### `todo_passed`

```perl
## the test numbers which unexpectedly succeeded
my @todo_passed = $parser->todo_passed;

## the number of tests which unexpectedly succeeded
my $todo_passed = $parser->todo_passed;
```

This method lets you know which (or how many) tests actually passed but were
declared as "TODO" tests.

#### `todo_failed`

```text
## deprecated in favor of 'todo_passed'.  This method was horribly misnamed.
```

This was a badly misnamed method.  It indicates which TODO tests unexpectedly
succeeded.  Will now issue a warning and call `todo_passed`.

#### `skipped`

```perl
my @skipped = $parser->skipped; # the test numbers with SKIP directives
my $skipped = $parser->skipped; # the number of tests with SKIP directives
```

This method lets you know which (or how many) tests had SKIP directives.

### Pragmas

#### `pragma`

Get or set a pragma. To get the state of a pragma:

```perl
if ( $p->pragma('strict') ) {
    # be strict
}
```

To set the state of a pragma:

```perl
$p->pragma('strict', 1); # enable strict mode
```

#### `pragmas`

Get a list of all the currently enabled pragmas:

```perl
my @pragmas_enabled = $p->pragmas;
```

### Summary Results

These results are "meta" information about the total results of an individual
test program.

#### `plan`

```perl
my $plan = $parser->plan;
```

Returns the test plan, if found.

#### `good_plan`

Deprecated.  Use `is_good_plan` instead.

#### `is_good_plan`

```perl
if ( $parser->is_good_plan ) { ... }
```

Returns a boolean value indicating whether or not the number of tests planned
matches the number of tests run.

**Note:**  this was formerly `good_plan`.  The latter method is deprecated and
will issue a warning.

And since we're on that subject ...

#### `tests_planned`

```perl
print $parser->tests_planned;
```

Returns the number of tests planned, according to the plan.  For example, a
plan of '1..17' will mean that 17 tests were planned.

#### `tests_run`

```perl
print $parser->tests_run;
```

Returns the number of tests which actually were run.  Hopefully this will
match the number of `$parser->tests_planned`.

#### `skip_all`

Returns a true value (actually the reason for skipping) if all tests
were skipped.

#### `start_time`

Returns the wall-clock time when the Parser was created.

#### `end_time`

Returns the wall-clock time when the end of TAP input was seen.

#### `start_times`

Returns the CPU times (like ["times" in perlfunc](../core/perlfunc/times.md) when the Parser was created.

#### `end_times`

Returns the CPU times (like ["times" in perlfunc](../core/perlfunc/times.md) when the end of TAP
input was seen.

#### `has_problems`

```perl
if ( $parser->has_problems ) {
    ...
}
```

This is a 'catch-all' method which returns true if any tests have currently
failed, any TODO tests unexpectedly succeeded, or any parse errors occurred.

#### `version`

```perl
$parser->version;
```

Once the parser is done, this will return the version number for the
parsed TAP. Version numbers were introduced with TAP version 13 so if no
version number is found version 12 is assumed.

#### `exit`

```perl
$parser->exit;
```

Once the parser is done, this will return the exit status.  If the parser ran
an executable, it returns the exit status of the executable.

#### `wait`

```perl
$parser->wait;
```

Once the parser is done, this will return the wait status.  If the parser ran
an executable, it returns the wait status of the executable.  Otherwise, this
merely returns the `exit` status.

### `ignore_exit`

```perl
$parser->ignore_exit(1);
```

Tell the parser to ignore the exit status from the test when determining
whether the test passed. Normally tests with non-zero exit status are
considered to have failed even if all individual tests passed. In cases
where it is not possible to control the exit value of the test script
use this option to ignore it.

#### `parse_errors`

```perl
my @errors = $parser->parse_errors; # the parser errors
my $errors = $parser->parse_errors; # the number of parser_errors
```

Fortunately, all TAP output is perfect.  In the event that it is not, this
method will return parser errors.  Note that a junk line which the parser does
not recognize is `not` an error.  This allows this parser to handle future
versions of TAP.  The following are all TAP errors reported by the parser:

- Misplaced plan

    The plan (for example, '1..5'), must only come at the beginning or end of the
    TAP output.

- No plan

    Gotta have a plan!

- More than one plan

    ```text
    1..3
    ok 1 - input file opened
    not ok 2 - first line of the input valid # todo some data
    ok 3 read the rest of the file
    1..3
    ```

    Right.  Very funny.  Don't do that.

- Test numbers out of sequence

    ```text
    1..3
    ok 1 - input file opened
    not ok 2 - first line of the input valid # todo some data
    ok 2 read the rest of the file
    ```

    That last test line above should have the number '3' instead of '2'.

    Note that it's perfectly acceptable for some lines to have test numbers and
    others to not have them.  However, when a test number is found, it must be in
    sequence.  The following is also an error:

    ```text
    1..3
    ok 1 - input file opened
    not ok - first line of the input valid # todo some data
    ok 2 read the rest of the file
    ```

    But this is not:

    ```text
    1..3
    ok  - input file opened
    not ok - first line of the input valid # todo some data
    ok 3 read the rest of the file
    ```

#### `get_select_handles`

Get an a list of file handles which can be passed to `select` to
determine the readiness of this parser.

#### `delete_spool`

Delete and return the spool.

```perl
my $fh = $parser->delete_spool;
```

## CALLBACKS

As mentioned earlier, a "callback" key may be added to the
`TAP::Parser` constructor. If present, each callback corresponding to a
given result type will be called with the result as the argument if the
`run` method is used. The callback is expected to be a subroutine
reference (or anonymous subroutine) which is invoked with the parser
result as its argument.

```perl
my %callbacks = (
    test    => \&test_callback,
    plan    => \&plan_callback,
    comment => \&comment_callback,
    bailout => \&bailout_callback,
    unknown => \&unknown_callback,
);

my $aggregator = TAP::Parser::Aggregator->new;
for my $file ( @test_files ) {
    my $parser = TAP::Parser->new(
        {
            source    => $file,
            callbacks => \%callbacks,
        }
    );
    $parser->run;
    $aggregator->add( $file, $parser );
}
```

Callbacks may also be added like this:

```perl
$parser->callback( test => \&test_callback );
$parser->callback( plan => \&plan_callback );
```

The following keys allowed for callbacks. These keys are case-sensitive.

- `test`

    Invoked if `$result->is_test` returns true.

- `version`

    Invoked if `$result->is_version` returns true.

- `plan`

    Invoked if `$result->is_plan` returns true.

- `comment`

    Invoked if `$result->is_comment` returns true.

- `bailout`

    Invoked if `$result->is_unknown` returns true.

- `yaml`

    Invoked if `$result->is_yaml` returns true.

- `unknown`

    Invoked if `$result->is_unknown` returns true.

- `ELSE`

    If a result does not have a callback defined for it, this callback will
    be invoked. Thus, if all of the previous result types are specified as
    callbacks, this callback will _never_ be invoked.

- `ALL`

    This callback will always be invoked and this will happen for each
    result after one of the above callbacks is invoked.  For example, if
    [Term::ANSIColor](../Term/ANSIColor.md) is loaded, you could use the following to color your
    test output:

    ```perl
    my %callbacks = (
        test => sub {
            my $test = shift;
            if ( $test->is_ok && not $test->directive ) {
                # normal passing test
                print color 'green';
            }
            elsif ( !$test->is_ok ) {    # even if it's TODO
                print color 'white on_red';
            }
            elsif ( $test->has_skip ) {
                print color 'white on_blue';

            }
            elsif ( $test->has_todo ) {
                print color 'white';
            }
        },
        ELSE => sub {
            # plan, comment, and so on (anything which isn't a test line)
            print color 'black on_white';
        },
        ALL => sub {
            # now print them
            print shift->as_string;
            print color 'reset';
            print "\n";
        },
    );
    ```

- `EOF`

    Invoked when there are no more lines to be parsed. Since there is no
    accompanying [TAP::Parser::Result](Parser/Result.md) object the `TAP::Parser` object is
    passed instead.

## TAP GRAMMAR

If you're looking for an EBNF grammar, see [TAP::Parser::Grammar](Parser/Grammar.md).

## BACKWARDS COMPATIBILITY

The Perl-QA list attempted to ensure backwards compatibility with
[Test::Harness](../Test/Harness.md).  However, there are some minor differences.

### Differences

- TODO plans

    A little-known feature of [Test::Harness](../Test/Harness.md) is that it supported TODO
    lists in the plan:

    ```text
    1..2 todo 2
    ok 1 - We have liftoff
    not ok 2 - Anti-gravity device activated
    ```

    Under [Test::Harness](../Test/Harness.md), test number 2 would _pass_ because it was
    listed as a TODO test on the plan line. However, we are not aware of
    anyone actually using this feature and hard-coding test numbers is
    discouraged because it's very easy to add a test and break the test
    number sequence. This makes test suites very fragile. Instead, the
    following should be used:

    ```text
    1..2
    ok 1 - We have liftoff
    not ok 2 - Anti-gravity device activated # TODO
    ```

- 'Missing' tests

    It rarely happens, but sometimes a harness might encounter
    'missing tests:

    ```text
    ok 1
    ok 2
    ok 15
    ok 16
    ok 17
    ```

    [Test::Harness](../Test/Harness.md) would report tests 3-14 as having failed. For the
    `TAP::Parser`, these tests are not considered failed because they've
    never run. They're reported as parse failures (tests out of sequence).

## SUBCLASSING

If you find you need to provide custom functionality (as you would have using
[Test::Harness::Straps](https://metacpan.org/pod/Test::Harness::Straps)), you're in luck: `TAP::Parser` and friends are
designed to be easily plugged-into and/or subclassed.

Before you start, it's important to know a few things:

1. All `TAP::*` objects inherit from [TAP::Object](Object.md).
2. Many `TAP::*` classes have a _SUBCLASSING_ section to guide you.
3. Note that `TAP::Parser` is designed to be the central "maker" - ie: it is
responsible for creating most new objects in the `TAP::Parser::*` namespace.

    This makes it possible for you to have a single point of configuring what
    subclasses should be used, which means that in many cases you'll find
    you only need to sub-class one of the parser's components.

    The exception to this rule are _SourceHandlers_ & _Iterators_, but those are
    both created with customizable _IteratorFactory_.

4. By subclassing, you may end up overriding undocumented methods.  That's not
a bad thing per se, but be forewarned that undocumented methods may change
without warning from one release to the next - we cannot guarantee backwards
compatibility.  If any _documented_ method needs changing, it will be
deprecated first, and changed in a later release.

### Parser Components

#### Sources

A TAP parser consumes input from a single _raw source_ of TAP, which could come
from anywhere (a file, an executable, a database, an IO handle, a URI, etc..).
The source gets bundled up in a [TAP::Parser::Source](Parser/Source.md) object which gathers some
meta data about it.  The parser then uses a [TAP::Parser::IteratorFactory](Parser/IteratorFactory.md) to
determine which [TAP::Parser::SourceHandler](Parser/SourceHandler.md) to use to turn the raw source
into a stream of TAP by way of "Iterators".

If you simply want `TAP::Parser` to handle a new source of TAP you probably
don't need to subclass `TAP::Parser` itself.  Rather, you'll need to create a
new [TAP::Parser::SourceHandler](Parser/SourceHandler.md) class, and just plug it into the parser using
the _sources_ param to "new".  Before you start writing one, read through
[TAP::Parser::IteratorFactory](Parser/IteratorFactory.md) to get a feel for how the system works first.

If you find you really need to use your own iterator factory you can still do
so without sub-classing `TAP::Parser` by setting "iterator\_factory\_class".

If you just need to customize the objects on creation, subclass [TAP::Parser](Parser.md)
and override "make\_iterator\_factory".

Note that `make_source` & `make_perl_source` have been _DEPRECATED_ and
are now removed.

#### Iterators

A TAP parser uses _iterators_ to loop through the _stream_ of TAP read in
from the _source_ it was given.  There are a few types of Iterators available
by default, all sub-classes of [TAP::Parser::Iterator](Parser/Iterator.md).  Choosing which
iterator to use is the responsibility of the _iterator factory_, though it
simply delegates to the _Source Handler_ it uses.

If you're writing your own [TAP::Parser::SourceHandler](Parser/SourceHandler.md), you may need to
create your own iterators too.  If so you'll need to subclass
[TAP::Parser::Iterator](Parser/Iterator.md).

Note that "make\_iterator" has been _DEPRECATED_ and is now removed.

#### Results

A TAP parser creates [TAP::Parser::Result](Parser/Result.md)s as it iterates through the
input _stream_.  There are quite a few result types available; choosing
which class to use is the responsibility of the _result factory_.

To create your own result types you have two options:

- option 1

    Subclass [TAP::Parser::Result](Parser/Result.md) and register your new result type/class with
    the default [TAP::Parser::ResultFactory](Parser/ResultFactory.md).

- option 2

    Subclass [TAP::Parser::ResultFactory](Parser/ResultFactory.md) itself and implement your own
    [TAP::Parser::Result](Parser/Result.md) creation logic.  Then you'll need to customize the
    class used by your parser by setting the `result_factory_class` parameter.
    See "new" for more details.

If you need to customize the objects on creation, subclass [TAP::Parser](Parser.md) and
override "make\_result".

#### Grammar

[TAP::Parser::Grammar](Parser/Grammar.md) is the heart of the parser.  It tokenizes the TAP
input _stream_ and produces results.  If you need to customize its behaviour
you should probably familiarize yourself with the source first.  Enough
lecturing.

Subclass [TAP::Parser::Grammar](Parser/Grammar.md) and customize your parser by setting the
`grammar_class` parameter.  See "new" for more details.

If you need to customize the objects on creation, subclass [TAP::Parser](Parser.md) and
override "make\_grammar"

## ACKNOWLEDGMENTS

All of the following have helped. Bug reports, patches, (im)moral
support, or just words of encouragement have all been forthcoming.

- Michael Schwern
- Andy Lester
- chromatic
- GEOFFR
- Shlomi Fish
- Torsten Schoenfeld
- Jerry Gay
- Aristotle
- Adam Kennedy
- Yves Orton
- Adrian Howard
- Sean & Lil
- Andreas J. Koenig
- Florian Ragwitz
- Corion
- Mark Stosberg
- Matt Kraai
- David Wheeler
- Alex Vandiver
- Cosimo Streppone
- Ville Skyttä

## AUTHORS

Curtis "Ovid" Poe <ovid@cpan.org>

Andy Armstong <andy@hexten.net>

Eric Wilhelm @ &lt;ewilhelm at cpan dot org>

Michael Peters &lt;mpeters at plusthree dot com>

Leif Eriksen &lt;leif dot eriksen at bigpond dot com>

Steve Purkis <spurkis@cpan.org>

Nicholas Clark <nick@ccl4.org>

Lee Johnson &lt;notfadeaway at btinternet dot com>

Philippe Bruhat <book@cpan.org>

## BUGS

Please report any bugs or feature requests to
`bug-test-harness@rt.cpan.org`, or through the web interface at
[http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Test-Harness](http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Test-Harness).
We will be notified, and then you'll automatically be notified of
progress on your bug as we make changes.

Obviously, bugs which include patches are best. If you prefer, you can
patch against bleed by via anonymous checkout of the latest version:

```text
git clone git://github.com/Perl-Toolchain-Gang/Test-Harness.git
```

## COPYRIGHT & LICENSE

Copyright 2006-2008 Curtis "Ovid" Poe, all rights reserved.

This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

## Modules

- [`TAP::Parser::Aggregator`](Parser/Aggregator.md) - Aggregate TAP::Parser results
- [`TAP::Parser::Grammar`](Parser/Grammar.md) - A grammar for the Test Anything Protocol.
- [`TAP::Parser::Iterator`](Parser/Iterator.md) - Base class for TAP source iterators
- [`TAP::Parser::IteratorFactory`](Parser/IteratorFactory.md) - Figures out which SourceHandler objects to use for a given Source
- [`TAP::Parser::Multiplexer`](Parser/Multiplexer.md) - Multiplex multiple TAP::Parsers
- [`TAP::Parser::Result`](Parser/Result.md) - Base class for TAP::Parser output objects
- [`TAP::Parser::ResultFactory`](Parser/ResultFactory.md) - Factory for creating TAP::Parser output objects
- [`TAP::Parser::Scheduler`](Parser/Scheduler.md) - Schedule tests during parallel testing
- [`TAP::Parser::Source`](Parser/Source.md) - a TAP source & meta data about it
- [`TAP::Parser::SourceHandler`](Parser/SourceHandler.md) - Base class for different TAP source handlers
- [`TAP::Parser::YAMLish`](Parser/YAMLish.md)

```{toctree}
:hidden:
:maxdepth: 1

Parser/Aggregator
Parser/Grammar
Parser/Iterator
Parser/IteratorFactory
Parser/Multiplexer
Parser/Result
Parser/ResultFactory
Parser/Scheduler
Parser/Source
Parser/SourceHandler
Parser/YAMLish
```