TABLE(1)						User Contributed Perl Documentation						  TABLE(1)

NAME

       APR::Table -- A Perl API for manipulating opaque string-content table

SYNOPSIS

	 use APR::Table;

	 $table = make($pool, $nelts);
	 $table_copy = $table->copy($pool);

	 $table->clear();

	 $table->set($key => $val);
	 $table->unset($key);
	 $table->add($key, $val);

	 $val = $table->get($key);
	 @val = $table->get($key);

	 $table->merge($key => $val);
	 overlap($table_a, $table_b, $flags);
	 $new_table = overlay($table_base, $table_overlay, $pool);

	 $table->do(sub {print "key $_[0], value $_[1]
"}, @valid_keys);

	 #Tied Interface
	 $value = $table->{$key};
	 $table->{$key} = $value;
	 $table->{$key} = $value;
	 exists $table->{$key};

	 foreach my $key (keys %{$table}) {
	     print "$key = $table->{$key}
";
	 }

DESCRIPTION

       "APR::Table" allows its users to manipulate opaque string-content tables.

       The table's structure is somewhat similar to the Perl's hash structure, but allows multiply values for the same key.  An access to the
       records stored in the table always requires a key.

       The key-value pairs are stored in the order they are added.

       The keys are case-insensitive.

       However as of the current implementation if more than value for the same key is requested, the whole table is lineary searched, which is
       very inefficient unless the table is very small.

       "APR::Table" provides a TIE Interface.

       See apr/include/apr_tables.h in ASF's apr project for low level details.

API

       The variables used in the API definition have the following "types":

       o APR::Table
	   "$table_*"

       o APR::Pool
	   $pool

       o scalars: unsigned integers only (SVIV) (as C expects them)
	   $nelts, $flags

       o scalars: (numerical (SVIV/SVNV) and strings (SVPV))
	   $key, $val

       Function arguments (if any) and return values are shown in the function's synopsis.

       o make()
	     $table = make($pool, $nelts);

	   Make a new table.

	   param $pool: The pool to allocate the pool out of.

	   param $nelts: The number of elements in the initial table.

	   return: a new table.

	   warning: This table can only store text data

       o copy()
	     $table_copy = $table->copy($pool);

	   Create a new table and copy another table into it

	   param $pool: The pool to allocate the new table out of

	   param $table: The table to copy

	   return: A copy of the table passed in

       o clear()
	     $table->clear();

	   Delete all of the elements from a table.

	   param $table: A copy of the table passed in

       o set();
	     $table->set($key => $val);

	   Add a key/value pair to a table, if another element already exists with the same key, this will over-write the old data.

	   param $table: The table to add the data to.

	   param $key: The key fo use.

	   param $val: The value to add.

       o add()
	     $table->add($key, $val);

	   Add data to a table, regardless of whether there is another element with the same key.

	   param $table: The table to add to

	   param $key: The key to use

	   param $val: The value to add.

       o do()
	     $table->do(sub {[...]}, [@filter]);

	   Iterate over all the elements of the table, invoking provided subroutine for each element.  The subroutine gets passed as argument, a
	   key-value pair.

	   The subroutine can abort the iteration by returning 0 and should always return 1 otherwise.

	   param "sub": A subroutine reference or name to be called on each item in the table

	   param @filter: Only keys matching one of the entries in the filter will be processed

       o get()
	     $val = $table->get($key);
	     @val = $table->get($key);

	   Get the value(s) associated with a given key.

	   After this call, the data is still in the table.

	   param $table: The table to search for the key

	   param $key: The key to search for

	   return: In the scalar context the first matching value returned. (The oldest in the table, if there is more than one value.) In the
	   list context the whole table is traversed and all matching values are returned. If nothing matches undef is returned.

       o unset();
	     $table->unset($key);

	   Remove data from the table

	   param $table: The table to remove data from

	   param $key: The key of the data being removed

       o merge()
	     $table->merge($key => $val);

	   Add data to a table by merging the value with data that has already been stored

	   param $table: The table to search for the data

	   param $key: The key to merge data for

	   param $val: The data to add

	   remark: If the key is not found, then this function acts like add()

       o overlap()
	     overlap($table_a, $table_b, $flags);

	   For each key/value pair in $table_b, add the data to $table_a. The definition of $flags explains how $flags define the overlapping
	   method.

	   param $table_a: The table to add the data to.

	   param $table_b: The table to iterate over, adding its data to %table_a.

	   param $flags: How to add the $table_b to $table_a.

	   When $flags == "APR_OVERLAP_TABLES_SET", if another element already exists with the same key, this will over-write the old data.

	   When $flags == "APR_OVERLAP_TABLES_MERGE", the key/value pair from $table_b is added, regardless of whether there is another element
	   with the same key in $table_a.

	   remark: This function is highly optimized, and uses less memory and CPU cycles than a function that just loops through table b calling
	   other functions.

       o overlay()
	     $new_table = overlay($table_base, $table_overlay, $pool);

	   Merge two tables into one new table. The resulting table may have more than one value for the same key.

	   param $pool: The pool to use for the new table

	   param $table_overlay: The first table to put in the new table

	   param $table_base: The table to add at the end of the new table

	   return: A new table containing all of the data from the two passed in

       TIE Interface

       "APR::Table" also implements a tied interface, so you can work with the $table object as a hash reference.

       The following tied-hash function are supported: FETCH, STORE, DELETE, CLEAR, EXISTS, FIRSTKEY, NEXTKEY and DESTROY.

       remark: "APR::Table" can hold more than one key-value pair sharing the same key, so when using a table through the tied interface, the
       first entry found with the right key will be used, completely disregarding possible other entries with the same key.  The only exception to
       this is if you iterate over the list with each, then you can access all key-value pairs that share the same key.

perl v5.8.0							    2002-05-19								  TABLE(1)