p1076_chap_04

Such a file is an explicitly declared file

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: e_declaration ::= file identifier_list : subtype_indication [ file_open_information ] ; file_open_information ::= [ open file_open_kind_expression ] is file_logical_name file_logical_name ::= string_expression The subtype indication of a file declaration must define a file subtype. If file open information is included in a given file declaration, then the file declared by the declaration is opened (see 3.4.1) with an implicit call to FILE_OPEN when the file declaration is elaborated (see 12.3.1.4). This implicit call is to the FILE_OPEN procedure of the first form, and it associates the identifier with the file parameter F, the file logical name with the External_Name parameter, and the file open kind expression with the Open_Kind parameter. If a file open kind expression is not included in the file open information of a given file declaration, then the default value of READ_MODE is used during elaboration of the file declaration. If file open information is not included in a given file declaration, then the file declared by the declaration is not opened when the file declaration is elaborated. The file logical name must be an expression of...
View Full Document

Ask a homework question - tutors are online