Devel::MAT::Cmd - abstractions for providing commands for Devel::MAT



  Devel::MAT::Cmd->printf( $fmt, @args )

Behaves like perl's core printf() function. Additionally, any argument for a %s conversion may also be the result of one of the following format_* methods, which may return a String::Tagged instance.

  Devel::MAT::Cmd->print_table( $rows, %opts )

Given a 2D array-of-arrays containing strings (which may be plain or formatted ones returned by the various format_* methods), prints them formatted in a table shape, aligning the columns.

An element of $rows may be an empty arrayref. This will cause a row of divisions to be drawn using hyphens (-) the full width of each column.

The following named %ops may be supplied:

headings => ARRAY[STRING]

A list of strings per column to place at the top of the table. These may be formatted differently to distinguish them.


A list of strings per column (or one single string to apply equally to them all) specifying the separator string to print after each columns. Will default to a single space if not supplied. Note that this string is interpolated into a sprintf format string, so any % marks it may contain should be doubled.


A list of strings per column (or one single string to apply equally to them all) specifying the alignment of data in the column. Aligns to the right if the value is "right".

indent => INT

A number of spaces to prefix before every row of output. Defaults to zero if not supplied.


  $str = Devel::MAT::Cmd->format_note( $str, $idx )

Apply some sort of styling to the a given string.

Starting from zero, successively higher integer values for $idx may influence the style further. Output with the same index value will appear the same. The implementation should support at least 3 different styles, but may wrap after this.

For stylistic consistency, tools should try to stick to the following conventions for note indexes:

  0 - regular notes
  1 - secondary notes, lexical variable names
  2 - unusual or erroneous conditions, symbol table names


  $str = Devel::MAT::Cmd->format_sv( $sv )

Returns a string encoding the address and description of the given SV, possibly stylised in some way, subject to user customisation, or possibly made interactive if the UI allows it to be so.


  $str = Devel::MAT::Cmd->format_value( $val, %opts )

Returns a string formatting a given plain scalar value (which should either be a string or a number) to indicate it's a value from the user program. If given a string value, this will be escaped and quoted appropriately.

The following named %opts may be supplied:

key => BOOL

If true, the value represents a hash key value. Wraps the result in braces {...} and removes redundant quote marks if the string is valid as a bareword identifier.

index => BOOL

If true, the value represents an array index. Wraps the result in square brackets [...] and expects the value to be an integer.

pv => BOOL

If true, the value represents a string from the user code. Wraps the result in quote marks "..." and limits the length to a maximum of 64 characters (or as specified by the maxlen argument). No truncation if maxlen is zero.


  $str = Devel::MAT::Cmd->format_symbol( $name, $sv )

Returns a string formatting the given symbol name to indicate that it is a symbol name. Optionally, the SV object itself can be passed too, which may save the UI having to look it up from the dumpfile in case it wishes to make the printed value interactive in some way.


  $str = Devel::MAT::Cmd->format_bytes( $bytes )

Returns a string showing the given byte count in suitably scaled units. This will use base-1024 sizes in KiB, MiB, GiB or TiB if necessary.


  $str = Devel::MAT::Cmd->format_sv_with_value( $sv )

Similar to "format_sv", but more helpful on SCALAR and REF SVs. For SCALAR SVs it will show the value directly by using "format_value", and for REF SVs it will show the referrant SV.


  $str = Devel::MAT::Cmd->format_heading( $text, $level )

Returns a string applying some formatting to the given text to make it stand out as a section or table heading. $level may be used to distinguish different styles; at least 3 should be provided.


Paul Evans <>