A.8.3 Sequential Input-Output Operations

Static Semantics

The operations available for sequential input and output are described in this subclause. The exception Status_Error is propagated if any of these operations is attempted for a file that is not open.

procedure Read(File : in File_Type; Item : out Element_Type);

Operates on a file of mode In_File. Reads an element from the given file, and returns the value of this element in the Item parameter.

The exception Mode_Error is propagated if the mode is not In_File. The exception End_Error is propagated if no more elements can be read from the given file. The exception Data_Error can be propagated if the element read cannot be interpreted as a value of the subtype Element_Type (see A.13, Exceptions in Input-Output).

procedure Write(File : in File_Type; Item : in Element_Type);

Operates on a file of mode Out_File or Append_File. Writes the value of Item to the given file.

The exception Mode_Error is propagated if the mode is not Out_File or Append_File. The exception Use_Error is propagated if the capacity of the external file is exceeded.

function End_Of_File(File : in File_Type) return Boolean;

Operates on a file of mode In_File. Returns True if no more elements can be read from the given file; otherwise returns False.

The exception Mode_Error is propagated if the mode is not In_File.

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