STRUCT +statement

+<struct-statement> +struct-statement ::= +STRUCT <struct-name> [ BYTE | WORD ] { <struct-member-list> } +

A STRUCT statement defines the format of a struct; all +resources are defined in terms of structs. The struct has a name designated +by struct-name, and some items designated by struct-member-list.

Struct names

The following rules must +be observed for struct-names:

they must be given in +upper case
they must begin with +an alphabetic character, although subsequent characters may be numeric
they may not begin with +any of the 12 struct type-names (see STRUCT +members), or the keywords: GLOBAL, STRUCT, LEN or RESOURCE. +This restriction applies only to the struct-name, not the member-name of +any individual struct members.

So the following struct definition will +generate an error
STRUCT BUFTHING + { + BUF buffer; + }
whereas this struct definition will compile correctly
STRUCT ABUFTHING + { + BUF buffer; + }

Struct member list

The struct-member-list is +a sequence of struct-member s where each member is terminated +by a semi-colon. The complete list is enclosed within a pair of braces.

See STRUCT members for +more details.

BYTE/WORD keywords

STRUCT definitions +allow resource instances to be of variable length, as the struct can allow +default variables for its members. A resource’s entire length can be deduced +from the position of the next resource; this information is available in a +resource file’s index. If the resource is used as a member within an instance +of another resource, however, its length must be identified another +way.

Use BYTE to +prefix the struct with a single byte indicating its length (zero to 255 characters).
Use WORD to +prefix the struct with a word indicating its length (zero to 65,535 characters).

The following are valid STRUCT statements:

STRUCT STRING + { + LTEXT str; + }

This defines a struct called STRING which +contains a single LTEXT item.

STRUCT TEST BYTE + { + WORD status; + STRUCT text; + }

This defines a struct called TEST which +contains a WORD and an embedded struct. The total length +of TEST is unknown, but should not exceed 255 characters: +the BYTE directive in the definition indicates that, when +this struct is embedded within another, it should be preceded with a byte +indicating its length (zero to 255 characters).