Editing Pascal (programming language) (section)

===File type===

:<syntaxhighlight lang="pascal">
type
    a = file of integer;
    b = record
        x : integer;
        y : char
    end;
    c = file of b;
</syntaxhighlight>

As shown in the example above, Pascal [[Computer file|files]] are sequences of components. Every file has a buffer variable which is denoted by ''f^''. The procedures ''get'' (for reading) and ''put'' (for writing) move the buffer variable to the next element. Read is introduced such that ''read(f, x)'' is the same as ''x := f^;  get(f);''. Write is introduced such that ''write(f, x)'' is the same as ''f^ := x;  put(f);'' The type {{code|text}} is predefined as file of char. While the buffer variable could be used for inspecting the next character to be used (check for a digit before reading an integer), this leads to serious problems with interactive programs in early implementations, but was solved later with the "lazy I/O" concept, which waits until the file buffer variable is actually accessed before performing file operations.