File Format Syntax

The TRI/2 file format syntax can be described by the following tokens:

Header:

ISO-10303-21;

HEADER;

FILE_DESCRIPTION(’....’);

FILE_NAME(‘....’,’....);

FILE_SCHEMA((’TRI/2’,’....’));

ENDSEC;

Data Part:

DATA;

#<unique id>=<entity name>(<list of attributes>);

#........

ENDSEC;

END-ISO-10303-21;

The contents of the data part are defined by entities with unique id’s. These id’s can be used as pointers in attribute lists of owner entities. The entity name and the list of attributes are defined in the EXPRESS schema. For example the EXPRESS syntax for the date_and_time entity looks like this:

The file format for a date_and_time instance could be written as follows:

#100=date_and_time(1997,7,1,10,30,1);

The token #100 is the pointer of the date_and_time instance. It could be referenced in another entity like:

#101=text(#100,(’line 1’, ’line 2’));

The entity attributes are separated by ‘,’

Syntax for STRING: ’test 1 ...’

Syntax for REAL: 12.2785 or 0.122785E+02

Syntax for Lists: (value1, value2, value3, ....)

Syntax for an empty list: ()

Symbol for unspecified attributes: ‘$’