Attribute description

Attribute description specifies how to read one particular attribute — typically, a single number, a string, array of bytes, etc. Attribute can also reference other complex structures by specifying user type given in type description. Each attribute is typically compiled into equivalent parsing instruction(s) in target language.

Common attributes

id

• Contents: a string that matches /^[a-z][a-z0-9_]*$/ — i.e. starts with lowercase letter and then may contain lowercase letters, numbers and underscore
• Purpose: identify attribute among others
• Influences: used as variable / field name in target programming language
• Mandatory: yes

type

• Contents: one of primitive data types or a user-specified type name
• Purpose: define a data type for an attribute
• Influences: how much bytes would be read, data type and contents of a variable in target programming language
• Mandatory: no — if type is not specified, then attribute is considered a generic byte sequence

Attributes that depend on type

No type specified

u*, s*

str

strz

User-specified types