# File format

The file format is defined in a formal way for sintax, in a informal for the semantic.

Definition of the metalanguage:

Definition

A = B means A is defined like B

Sequence

A + B means A is tied with B

Selection

A | B means A or B

Repetition

{A } means that it is possible repeat A a inprecisate number or time ( also zero ).

Optional

[ A ] means A or nothing

Non rapprentable simble

`description' in this way you can indicate a simbol the you can't print

Also:

An identificator in bold means a terminal simbol, a normal identificator means a non terminal simbol.

Numeric definition

plus = `the simbol +'

dot = `the simbol .'

digit = [ 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 ]

number_integer = [ - | plus | ] + digit + { digit }

number_float = number_integer + [ . + { digit } ]

number_real = number_float + [ E + number_integer ]

number_integer

is an integer number (es. 18554).

number_float

is a number with comma (es. 34.87653).

number_real

is a number in scientific format (es. 13.47E-2 ).

definition of identificator

alfama = [ A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | X | Y | Z ]

alfami = [ a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v | x | y | z ]

alfa = [ alfama | alfami ]

ident_first = [ alfa | _ ]

ident_other = [ alfa | digit | _ ]

ident = ident_first + [ { ident_other } ]

ident_first

is the first character of an identifer.

ident_other

the type of all characters of an identifier but the first.

ident

declaretion of an identifier.

definition of a separator

( between identifiers or numbers or other )

ret_carriage = 'carriage return ( ASCII = 13 ) '

space = ' '

tab = ' tabulation character ( ASCII = 6) '

sep = { [ space | ret_carriage | tab ] }

The separator is used to separe two identifiers.

There is no difference between space, carriage return and tabulation.

Now we will use a new meta-operator dot ( . ), with the meaning of " + sep +".

For example: a . b is the same of "a b" or of "a b"

Other common definition

vector = ( . number_real . { , . number_real } . )

matrix = [ . number_real . { [ , | ; ] . number_real } . ]

point = ( . number_real . , . number_real . , . number_real . )

color = point

matrix

this definition is meaningfull if the groups which are separated from ; have the same number of elements separated from , .

For example [ 2 , 3 ; 4 1.2 ] is correct, [3, 1; 7 ] is not correct.

Section

For the text type definition the common way to represent the structured data is to create a section which contains the data with similar definition.

The definition prototype is :

section = { . sectionname . defsection . }

sectionname = ident

section

definition of whole section.

sectionname

definition of the type of the section.

defsection

declaration of the data in the section. It is impossible to define this non terminal; it must be defined every time.

- Definition of the file format
- File .bmp
- File .brp
- File .bzr
- File .rt
- Tecnical Information
- Bibliography