Free Hero Mesh

=== Level table definition ===

The following blocks are allowed in a level table definition:

(<label> <code...>)
  Define a data column. The SQL name of the data column will be that of
  the label name, preceded by a underscore, and some characters will be
  stripped out; note that SQL is case-insensitive. (Other implementations
  or ports of Free Hero Mesh might not implement it as a SQL column, or
  at all. For best portability, names should contain only ASCII letters,
  digits, and underscores, and should not start with a digit, and you
  should not define two or more data columns whose names differ only by
  their case. Aggregates are not subject to this restriction, though.)
  The label name must have a colon at front; if a comma is also added
  then numeric values of this column are treated as signed.

(<string> <label> <width> <format> <color>)
  Defines a display column. The <label> is the name of the data column.
  The <width> is a number 1 to 255 or it can be * for fill width; only
  the last column is allowed to be fill width (although it is also OK if
  no colums are fill width). The <format> is a string of exactly one or
  two characters; see the below list of possible formats. The <color> is
  the text colour, and is optional; it can be a number from 1 to 255, or
  it can be a sequence of parenthesized pairs of a number (-127 to +127)
  and colour, to mean use those colour if the value of this column is
  in range. It uses the colour for all values up to and including the
  specified number, so the numbers should be listed in ascending order,
  in order to work. The <string> is the heading; it is not allowed to
  include control characters, nor can it include graphic characters with
  code number less than 32.

(<local> <type> <code...>)
  Defines a aggregate calculation. The <local> is the name of the aggregate
  to be referred by other blocks (which must start with a percentage sign,
  like a local variable does). The <type> is the type of aggregate, which
  can be + (sum of all values), min (least value), or max (greatest value);
  any one with a comma at first means it is a signed aggregate.

The valid formats are:

* "L" or "R" = Left or right aligned text.

* "L*" or "R*" replacing * with any character = Left or right aligned
displaying the specified character repeated as many times as the column
value is.

* "d", "d-", "d+", "x", "x0", "X", "X0", "o", "o0", "u" = Display a number
(right aligned) as signed decimal (d), hexadecimal (x/X), octal (o),
unsigned decimal (u). The ones with "0" will pad by 0 instead of spaces,
and the "d-" and "d+" will display a left aligned sign.

If a numeric format is specified but it is a text value, then it is treated
as "L" instead, unless format is "R*" in which case it is treated as "R".

(TODO: Mention valid instructions.)