From: Darren Chamberlain Date: Wed, 29 Jan 2003 13:29:49 +0000 (+0000) Subject: Moved all POD to the end of the module, to make it easier X-Git-Tag: v0.01~24 X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=0f3778d0fbe3334bab28de4c08523e77360b6332;p=dbsrgits%2FSQL-Translator.git Moved all POD to the end of the module, to make it easier to modify and find. Added a bunch of inline documentation. Refactored a few of the duplicated methods, such as producer_args and parser_args. --- diff --git a/lib/SQL/Translator.pm b/lib/SQL/Translator.pm index b9d0727..32e79b4 100644 --- a/lib/SQL/Translator.pm +++ b/lib/SQL/Translator.pm @@ -1,7 +1,7 @@ package SQL::Translator; # ---------------------------------------------------------------------- -# $Id: Translator.pm,v 1.15 2003-01-27 17:04:43 dlc Exp $ +# $Id: Translator.pm,v 1.16 2003-01-29 13:29:49 dlc Exp $ # ---------------------------------------------------------------------- # Copyright (C) 2003 Ken Y. Clark , # darren chamberlain , @@ -22,48 +22,12 @@ package SQL::Translator; # 02111-1307 USA # ------------------------------------------------------------------- -=head1 NAME - -SQL::Translator - convert schema from one database to another - -=head1 SYNOPSIS - - use SQL::Translator; - - my $translator = SQL::Translator->new( - xlate => $xlate || {}, # Overrides for field translation - debug => $debug, # Print debug info - trace => $trace, # Print Parse::RecDescent trace - no_comments => $no_comments, # Don't include comments in output - show_warnings => $show_warnings, # Print name mutations, conflicts - add_drop_table => $add_drop_table, # Add "drop table" statements - ); - - my $output = $translator->translate( - from => "MySQL", - to => "Oracle", - filename => $file, - ) or die $translator->error; - - print $output; - -=head1 DESCRIPTION - -This module attempts to simplify the task of converting one database -create syntax to another through the use of Parsers (which understand -the source format) and Producers (which understand the destination -format). The idea is that any Parser can be used with any Producer in -the conversion process. So, if you wanted Postgres-to-Oracle, you -would use the Postgres parser and the Oracle producer. - -=cut - use strict; use vars qw( $VERSION $REVISION $DEFAULT_SUB $DEBUG $ERROR ); use base 'Class::Base'; $VERSION = '0.01'; -$REVISION = sprintf "%d.%02d", q$Revision: 1.15 $ =~ /(\d+)\.(\d+)/; +$REVISION = sprintf "%d.%02d", q$Revision: 1.16 $ =~ /(\d+)\.(\d+)/; $DEBUG = 0 unless defined $DEBUG; $ERROR = ""; @@ -80,35 +44,6 @@ use IO::Dir; # ---------------------------------------------------------------------- $DEFAULT_SUB = sub { $_[1] } unless defined $DEFAULT_SUB; -=head1 CONSTRUCTOR - -The constructor is called B, and accepts a optional hash of options. -Valid options are: - -=over 4 - -=item parser (aka from) - -=item parser_args - -=item producer (aka to) - -=item producer_args - -=item filename (aka file) - -=item data - -=item debug - -=back - -All options are, well, optional; these attributes can be set via -instance methods. Internally, they are; no (non-syntactical) -advantage is gained by passing options to the constructor. - -=cut - # ---------------------------------------------------------------------- # init([ARGS]) # The constructor. @@ -175,15 +110,9 @@ sub init { return $self; } -=head1 METHODS - -=head2 B - -Toggles whether or not to add "DROP TABLE" statements just before the -create definitions. - -=cut - +# ---------------------------------------------------------------------- +# add_drop_table([$bool]) +# ---------------------------------------------------------------------- sub add_drop_table { my $self = shift; if ( defined (my $arg = shift) ) { @@ -193,29 +122,18 @@ sub add_drop_table { } -=head2 B - -Allows the user to override default translation of fields. For example, -if a MySQL "text" field would normally be converted to a "long" for Oracle, -the user could specify to change it to a "CLOB." Accepts a hashref where -keys are the "from" value and values are the "to," returns the current -value of the field. - -=cut - +# ---------------------------------------------------------------------- +# custom_translate([$bool]) +# ---------------------------------------------------------------------- sub custom_translate { my $self = shift; $self->{'custom_translate'} = shift if @_; return $self->{'custom_translate'} || {}; } -=head2 B - -Toggles whether to print comments in the output. Accepts a true or false -value, returns the current value. - -=cut - +# ---------------------------------------------------------------------- +# no_comments([$bool]) +# ---------------------------------------------------------------------- sub no_comments { my $self = shift; my $arg = shift; @@ -225,76 +143,12 @@ sub no_comments { return $self->{'no_comments'} || 0; } -=head2 B - -The B method is an accessor/mutator, used to retrieve or -define what subroutine is called to produce the output. A subroutine -defined as a producer will be invoked as a function (I) -and passed 2 parameters: its container SQL::Translator instance and a -data structure. It is expected that the function transform the data -structure to a string. The SQL::Transformer instance is provided for -informational purposes; for example, the type of the parser can be -retrieved using the B method, and the B and -B methods can be called when needed. - -When defining a producer, one of several things can be passed -in: A module name (e.g., My::Groovy::Producer), a module name -relative to the SQL::Translator::Producer namespace (e.g., MySQL), a -module name and function combination (My::Groovy::Producer::transmogrify), -or a reference to an anonymous subroutine. If a full module name is -passed in (for the purposes of this method, a string containing "::" -is considered to be a module name), it is treated as a package, and a -function called "produce" will be invoked: $modulename::produce. If -$modulename cannot be loaded, the final portion is stripped off and -treated as a function. In other words, if there is no file named -My/Groovy/Producer/transmogrify.pm, SQL::Translator will attempt to load -My/Groovy/Producer.pm and use transmogrify as the name of the function, -instead of the default "produce". - - my $tr = SQL::Translator->new; - - # This will invoke My::Groovy::Producer::produce($tr, $data) - $tr->producer("My::Groovy::Producer"); - - # This will invoke SQL::Translator::Producer::Sybase::produce($tr, $data) - $tr->producer("Sybase"); - - # This will invoke My::Groovy::Producer::transmogrify($tr, $data), - # assuming that My::Groovy::Producer::transmogrify is not a module - # on disk. - $tr->producer("My::Groovy::Producer::transmogrify"); - - # This will invoke the referenced subroutine directly, as - # $subref->($tr, $data); - $tr->producer(\&my_producer); - -There is also a method named B, which is a string -containing the classname to which the above B function -belongs. In the case of anonymous subroutines, this method returns -the string "CODE". - -Finally, there is a method named B, which is both an -accessor and a mutator. Arbitrary data may be stored in name => value -pairs for the producer subroutine to access: - - sub My::Random::producer { - my ($tr, $data) = @_; - my $pr_args = $tr->producer_args(); - - # $pr_args is a hashref. - -Extra data passed to the B method is passed to -B: - $tr->producer("xSV", delimiter => ',\s*'); - - # In SQL::Translator::Producer::xSV: - my $args = $tr->producer_args; - my $delimiter = $args->{'delimiter'}; # value is ,\s* - -=cut - -# producer and producer_type +# ---------------------------------------------------------------------- +# producer([$producer_spec]) +# +# Get or set the producer for the current translator. +# ---------------------------------------------------------------------- sub producer { my $self = shift; @@ -359,7 +213,7 @@ sub producer { }; # ---------------------------------------------------------------------- -# producer_type +# producer_type() # # producer_type is an accessor that allows producer subs to get # information about their origin. This is poptentially important; @@ -370,62 +224,25 @@ sub producer { sub producer_type { $_[0]->{'producer_type'} } # ---------------------------------------------------------------------- -# producer_args +# producer_args([\%args]) # # Arbitrary name => value pairs of paramters can be passed to a # producer using this method. # -# XXX All calls to producer_args with a value clobbers old values! -# Should probably check if $_[0] is undef, and delete stored -# args if it is: -# -# if (@_) { -# unless (defined $_[0]) { -# %{ $self->{'producer_args'} } = (); -# } -# my $args = isa($_[0], 'HASH') ? shift : { @_ }; -# %{ $self->{'producer_args'} } = ( -# %{ $self->{'producer_args'} }, -# %{ $args } -# ); -# } +# If the first argument passed in is undef, then the hash of arguments +# is cleared; all subsequent elements are added to the hash of name, +# value pairs stored as producer_args. # ---------------------------------------------------------------------- sub producer_args { my $self = shift; - if (@_) { - my $args = isa($_[0], 'HASH') ? shift : { @_ }; - $self->{'producer_args'} = $args; - } - $self->{'producer_args'}; + return $self->_args("producer", @_); } -=head2 B - -The B method defines or retrieves a subroutine that will be -called to perform the parsing. The basic idea is the same as that of -B (see above), except the default subroutine name is -"parse", and will be invoked as $module_name::parse($tr, $data). -Also, the parser subroutine will be passed a string containing the -entirety of the data to be parsed. - - # Invokes SQL::Translator::Parser::MySQL::parse() - $tr->parser("MySQL"); - - # Invokes My::Groovy::Parser::parse() - $tr->parser("My::Groovy::Parser"); - - # Invoke an anonymous subroutine directly - $tr->parser(sub { - my $dumper = Data::Dumper->new([ $_[1] ], [ "SQL" ]); - $dumper->Purity(1)->Terse(1)->Deepcopy(1); - return $dumper->Dump; - }); - -There is also B and B, which perform -analogously to B and B -=cut +# ---------------------------------------------------------------------- +# parser([$parser_spec]) +# ---------------------------------------------------------------------- sub parser { my $self = shift; @@ -492,26 +309,10 @@ sub parser { # ---------------------------------------------------------------------- sub parser_type { $_[0]->{'parser_type'} } -# ---------------------------------------------------------------------- -# XXX See notes on producer_args, above sub parser_args { my $self = shift; - if (@_) { - my $args = isa($_[0], 'HASH') ? shift : { @_ }; - $self->{'parser_args'} = $args; - } - $self->{'parser_args'}; -} - -=head2 B - -Toggles whether to print warnings of name conflicts, identifier -mutations, etc. Probably only generated by producers to let the user -know when something won't translate very smoothly (e.g., MySQL "enum" -fields into Oracle). Accepts a true or false value, returns the -current value. - -=cut + return $self->_args("parser", @_); +} sub show_warnings { my $self = shift; @@ -522,117 +323,59 @@ sub show_warnings { return $self->{'show_warnings'} || 0; } -=head2 B -The B method calls the subroutines referenced by the -B and B data members (described above). It accepts -as arguments a number of things, in key => value format, including -(potentially) a parser and a producer (they are passed directly to the -B and B methods). +# filename - get or set the filename +sub filename { + my $self = shift; + if (@_) { + my $filename = shift; + if (-d $filename) { + my $msg = "Cannot use directory '$filename' as input source"; + return $self->error($msg); + } elsif (-f _ && -r _) { + $self->{'filename'} = $filename; + $self->debug("Got filename: '$self->{'filename'}'\n"); + } else { + my $msg = "Cannot use '$filename' as input source: ". + "file does not exist or is not readable."; + return $self->error($msg); + } + } -Here is how the parameter list to B is parsed: + $self->{'filename'}; +} -=over +# ---------------------------------------------------------------------- +# data([$data]) +# +# if $self->{'data'} is not set, but $self->{'filename'} is, then +# $self->{'filename'} is opened and read, with the results put into +# $self->{'data'}. +# ---------------------------------------------------------------------- +sub data { + my $self = shift; -=item * - -1 argument means it's the data to be parsed; which could be a string -(filename) or a refernce to a scalar (a string stored in memory), or a -reference to a hash, which is parsed as being more than one argument -(see next section). - - # Parse the file /path/to/datafile - my $output = $tr->translate("/path/to/datafile"); - - # Parse the data contained in the string $data - my $output = $tr->translate(\$data); - -=item * - -More than 1 argument means its a hash of things, and it might be -setting a parser, producer, or datasource (this key is named -"filename" or "file" if it's a file, or "data" for a SCALAR reference. - - # As above, parse /path/to/datafile, but with different producers - for my $prod ("MySQL", "XML", "Sybase") { - print $tr->translate( - producer => $prod, - filename => "/path/to/datafile", - ); - } - - # The filename hash key could also be: - datasource => \$data, - -You get the idea. - -=back - -=head2 B, B - -Using the B method, the filename of the data to be parsed -can be set. This method can be used in conjunction with the B -method, below. If both the B and B methods are -invoked as mutators, the data set in the B method is used. - - $tr->filename("/my/data/files/create.sql"); - -or: - - my $create_script = do { - local $/; - open CREATE, "/my/data/files/create.sql" or die $!; - ; - }; - $tr->data(\$create_script); - -B takes a string, which is interpreted as a filename. -B takes a reference to a string, which is used as the data to be -parsed. If a filename is set, then that file is opened and read when -the B method is called, as long as the data instance -variable is not set. - -=cut - -# filename - get or set the filename -sub filename { - my $self = shift; - if (@_) { - my $filename = shift; - if (-d $filename) { - my $msg = "Cannot use directory '$filename' as input source"; - return $self->error($msg); - } elsif (-f _ && -r _) { - $self->{'filename'} = $filename; - $self->debug("Got filename: '$self->{'filename'}'\n"); - } else { - my $msg = "Cannot use '$filename' as input source: ". - "file does not exist or is not readable."; - return $self->error($msg); - } - } - - $self->{'filename'}; -} - -# ---------------------------------------------------------------------- -# data - get or set the data -# if $self->{'data'} is not set, but $self->{'filename'} is, then -# $self->{'filename'} is opened and read, whith the results put into -# $self->{'data'}. -sub data { - my $self = shift; - - # Set $self->{'data'} to $_[0], if it is provided. - if (@_) { - my $data = shift; - if (isa($data, "SCALAR")) { - $self->{'data'} = $data; - } - elsif (! ref $data) { - $self->{'data'} = \$data; - } - } + # Set $self->{'data'} based on what was passed in. We will + # accept a number of things; do our best to get it right. + if (@_) { + my $data = shift; + if (isa($data, "SCALAR")) { + $self->{'data'} = $data; + } + else { + if (isa($data, 'ARRAY')) { + $data = join '', @$data; + } + elsif (isa($data, 'GLOB')) { + local $/; + $data = <$data>; + } + elsif (! ref $data && @_) { + $data = join '', $data, @_; + } + $self->{'data'} = \$data; + } + } # If we have a filename but no data yet, populate. if (not $self->{'data'} and my $filename = $self->filename) { @@ -656,13 +399,6 @@ sub data { return $self->{'data'}; } -=pod - -=head2 B - -Turns on/off the tracing option of Parse::RecDescent. - -=cut sub trace { my $self = shift; @@ -674,10 +410,22 @@ sub trace { } # ---------------------------------------------------------------------- -sub translate { - my $self = shift; - my ($args, $parser, $parser_type, $producer, $producer_type); - my ($parser_output, $producer_output); +# translate([source], [\%args]) +# +# translate does the actual translation. The main argument is the +# source of the data to be translated, which can be a filename, scalar +# reference, or glob reference. +# +# Alternatively, translate takes optional arguements, which are passed +# to the appropriate places. Most notable of these arguments are +# parser and producer, which can be used to set the parser and +# producer, respectively. This is the applications last chance to set +# these. +# +# translate returns a string. +# ---------------------------------------------------------------------- +sub translate { my $self = shift; my ($args, $parser, $parser_type, +$producer, $producer_type); my ($parser_output, $producer_output); # Parse arguments if (@_ == 1) { @@ -688,6 +436,12 @@ sub translate { $args = $_[0]; } + # Passed a GLOB reference, i.e., filehandle + elsif (isa($_[0], 'GLOB')) { + $self->debug("translate: Got a GLOB reference\n"); + $self->data($_[0]); + } + # Passed a reference to a string containing the data elsif (isa($_[0], 'SCALAR')) { # passed a ref to a string @@ -784,30 +538,94 @@ sub translate { } # ---------------------------------------------------------------------- +# list_parsers() +# +# Hacky sort of method to list all available parsers. This has +# several problems: +# +# - Only finds things in the SQL::Translator::Parser namespace +# +# - Only finds things that are located in the same directory +# as SQL::Translator::Parser. Yeck. +# +# This method will fail in several very likely cases: +# +# - Parser modules in different namespaces +# +# - Parser modules in the SQL::Translator::Parser namespace that +# have any XS componenets will be installed in +# arch_lib/SQL/Translator. +# +# ---------------------------------------------------------------------- +sub list_parsers { + return _list("parsers"); +} + +# ---------------------------------------------------------------------- +# list_producers() +# +# See notes for list_parsers(), above; all the problems apply to +# list_producers as well. +# ---------------------------------------------------------------------- sub list_producers { - require SQL::Translator::Producer; - my $path = catfile(dirname($INC{'SQL/Translator/Producer.pm'}), "Producer"); - my $dh = IO::Dir->new($path); + return _list("producers"); +} + - my @available = map { join "::", "SQL::Translator::Producer", $_ } - grep /\.pm$/, $dh->read; +# ====================================================================== +# Private Methods +# ====================================================================== - return @available; +# ---------------------------------------------------------------------- +# _args($type, \%args); +# +# Gets or sets ${type}_args. Called by parser_args and producer_args. +# ---------------------------------------------------------------------- +sub _args { + my $self = shift; + my $type = shift; + $type = "${type}_args" unless $type =~ /_args$/; + + unless (defined $self->{$type} && isa($self->{$type}, 'HASH')) { + $self->{$type} = { }; + } + + if (@_) { + # If the first argument is an explicit undef (remember, we + # don't get here unless there is stuff in @_), then we clear + # out the producer_args hash. + if (! defined $_[0]) { + shift @_; + %{$self->{$type}} = (); + } + + my $args = isa($_[0], 'HASH') ? shift : { @_ }; + %{$self->{$type}} = (%{$self->{$type}}, %$args); + } + + $self->{$type}; } + # ---------------------------------------------------------------------- -sub list_parsers { - require SQL::Translator::Parser; - my $path = catfile(dirname($INC{'SQL/Translator/Parser.pm'}), "Parser"); - my $dh = IO::Dir->new($path); +# _list($type) +# ---------------------------------------------------------------------- +sub _list { + my $type = ucfirst lc $_[0] || return (); - my @available = map { join "::", "SQL::Translator::Parser", $_ } - grep /\.pm$/, $dh->read; + load("SQL::Translator::$type"); + my $path = catfile(dirname($INC{'SQL/Translator/$type.pm'}), $type); + my $dh = IO::Dir->new($path); - return @available; + return map { join "::", "SQL::Translator::$type", $_ } + grep /\.pm$/, $dh->read; } # ---------------------------------------------------------------------- +# load($module) +# +# Loads a Perl module. Short circuits if a module is already loaded. +# ---------------------------------------------------------------------- sub load { my $module = do { my $m = shift; $m =~ s[::][/]g; "$m.pm" }; return 1 if $INC{$module}; @@ -819,15 +637,281 @@ sub load { } # ---------------------------------------------------------------------- -sub isa($$) { UNIVERSAL::isa($_[0], $_[1]) } +# isa($ref, $type) +# +# Calls UNIVERSAL::isa($ref, $type). I think UNIVERSAL::isa is ugly, +# but I like function overhead. +# ---------------------------------------------------------------------- +sub isa($$) { + my ($ref, $type) = @_; + return UNIVERSAL::isa($ref, $type); +} 1; - #----------------------------------------------------- # Rescue the drowning and tie your shoestrings. # Henry David Thoreau #----------------------------------------------------- +__END__ + +=head1 NAME + +SQL::Translator - convert schema from one database to another + +=head1 SYNOPSIS + + use SQL::Translator; + + my $translator = SQL::Translator->new( + xlate => $xlate || {}, # Overrides for field translation + debug => $debug, # Print debug info + trace => $trace, # Print Parse::RecDescent trace + no_comments => $no_comments, # Don't include comments in output + show_warnings => $show_warnings, # Print name mutations, conflicts + add_drop_table => $add_drop_table, # Add "drop table" statements + ); + + my $output = $translator->translate( + from => "MySQL", + to => "Oracle", + filename => $file, + ) or die $translator->error; + + print $output; + +=head1 DESCRIPTION + +This module attempts to simplify the task of converting one database +create syntax to another through the use of Parsers (which understand +the source format) and Producers (which understand the destination +format). The idea is that any Parser can be used with any Producer in +the conversion process. So, if you wanted Postgres-to-Oracle, you +would use the Postgres parser and the Oracle producer. + +=head1 CONSTRUCTOR + +The constructor is called B, and accepts a optional hash of options. +Valid options are: + +=over 4 + +=item parser (aka from) + +=item parser_args + +=item producer (aka to) + +=item producer_args + +=item filename (aka file) + +=item data + +=item debug + +=back + +All options are, well, optional; these attributes can be set via +instance methods. Internally, they are; no (non-syntactical) +advantage is gained by passing options to the constructor. + +=head1 METHODS + +=head2 B + +Toggles whether or not to add "DROP TABLE" statements just before the +create definitions. + +=head2 B + +Allows the user to override default translation of fields. For example, +if a MySQL "text" field would normally be converted to a "long" for Oracle, +the user could specify to change it to a "CLOB." Accepts a hashref where +keys are the "from" value and values are the "to," returns the current +value of the field. + +=head2 B + +Toggles whether to print comments in the output. Accepts a true or false +value, returns the current value. + +=head2 B + +The B method is an accessor/mutator, used to retrieve or +define what subroutine is called to produce the output. A subroutine +defined as a producer will be invoked as a function (I) +and passed 2 parameters: its container SQL::Translator instance and a +data structure. It is expected that the function transform the data +structure to a string. The SQL::Transformer instance is provided for +informational purposes; for example, the type of the parser can be +retrieved using the B method, and the B and +B methods can be called when needed. + +When defining a producer, one of several things can be passed +in: A module name (e.g., My::Groovy::Producer), a module name +relative to the SQL::Translator::Producer namespace (e.g., MySQL), a +module name and function combination (My::Groovy::Producer::transmogrify), +or a reference to an anonymous subroutine. If a full module name is +passed in (for the purposes of this method, a string containing "::" +is considered to be a module name), it is treated as a package, and a +function called "produce" will be invoked: $modulename::produce. If +$modulename cannot be loaded, the final portion is stripped off and +treated as a function. In other words, if there is no file named +My/Groovy/Producer/transmogrify.pm, SQL::Translator will attempt to load +My/Groovy/Producer.pm and use transmogrify as the name of the function, +instead of the default "produce". + + my $tr = SQL::Translator->new; + + # This will invoke My::Groovy::Producer::produce($tr, $data) + $tr->producer("My::Groovy::Producer"); + + # This will invoke SQL::Translator::Producer::Sybase::produce($tr, $data) + $tr->producer("Sybase"); + + # This will invoke My::Groovy::Producer::transmogrify($tr, $data), + # assuming that My::Groovy::Producer::transmogrify is not a module + # on disk. + $tr->producer("My::Groovy::Producer::transmogrify"); + + # This will invoke the referenced subroutine directly, as + # $subref->($tr, $data); + $tr->producer(\&my_producer); + +There is also a method named B, which is a string +containing the classname to which the above B function +belongs. In the case of anonymous subroutines, this method returns +the string "CODE". + +Finally, there is a method named B, which is both an +accessor and a mutator. Arbitrary data may be stored in name => value +pairs for the producer subroutine to access: + + sub My::Random::producer { + my ($tr, $data) = @_; + my $pr_args = $tr->producer_args(); + + # $pr_args is a hashref. + +Extra data passed to the B method is passed to +B: + + $tr->producer("xSV", delimiter => ',\s*'); + + # In SQL::Translator::Producer::xSV: + my $args = $tr->producer_args; + my $delimiter = $args->{'delimiter'}; # value is ,\s* + +=head2 B + +The B method defines or retrieves a subroutine that will be +called to perform the parsing. The basic idea is the same as that of +B (see above), except the default subroutine name is +"parse", and will be invoked as $module_name::parse($tr, $data). +Also, the parser subroutine will be passed a string containing the +entirety of the data to be parsed. + + # Invokes SQL::Translator::Parser::MySQL::parse() + $tr->parser("MySQL"); + + # Invokes My::Groovy::Parser::parse() + $tr->parser("My::Groovy::Parser"); + + # Invoke an anonymous subroutine directly + $tr->parser(sub { + my $dumper = Data::Dumper->new([ $_[1] ], [ "SQL" ]); + $dumper->Purity(1)->Terse(1)->Deepcopy(1); + return $dumper->Dump; + }); + +There is also B and B, which perform +analogously to B and B + +=head2 B + +Toggles whether to print warnings of name conflicts, identifier +mutations, etc. Probably only generated by producers to let the user +know when something won't translate very smoothly (e.g., MySQL "enum" +fields into Oracle). Accepts a true or false value, returns the +current value. + +=head2 B + +The B method calls the subroutines referenced by the +B and B data members (described above). It accepts +as arguments a number of things, in key => value format, including +(potentially) a parser and a producer (they are passed directly to the +B and B methods). + +Here is how the parameter list to B is parsed: + +=over + +=item * + +1 argument means it's the data to be parsed; which could be a string +(filename) or a refernce to a scalar (a string stored in memory), or a +reference to a hash, which is parsed as being more than one argument +(see next section). + + # Parse the file /path/to/datafile + my $output = $tr->translate("/path/to/datafile"); + + # Parse the data contained in the string $data + my $output = $tr->translate(\$data); + +=item * + +More than 1 argument means its a hash of things, and it might be +setting a parser, producer, or datasource (this key is named +"filename" or "file" if it's a file, or "data" for a SCALAR reference. + + # As above, parse /path/to/datafile, but with different producers + for my $prod ("MySQL", "XML", "Sybase") { + print $tr->translate( + producer => $prod, + filename => "/path/to/datafile", + ); + } + + # The filename hash key could also be: + datasource => \$data, + +You get the idea. + +=back + +=head2 B, B + +Using the B method, the filename of the data to be parsed +can be set. This method can be used in conjunction with the B +method, below. If both the B and B methods are +invoked as mutators, the data set in the B method is used. + + $tr->filename("/my/data/files/create.sql"); + +or: + + my $create_script = do { + local $/; + open CREATE, "/my/data/files/create.sql" or die $!; + ; + }; + $tr->data(\$create_script); + +B takes a string, which is interpreted as a filename. +B takes a reference to a string, which is used as the data to be +parsed. If a filename is set, then that file is opened and read when +the B method is called, as long as the data instance +variable is not set. + +=pod + +=head2 B + +Turns on/off the tracing option of Parse::RecDescent. + =pod =head1 AUTHORS @@ -859,4 +943,3 @@ L, L, L -=cut