
HISTORY - length of the history table

Calling sequence:
HISTORY := [ integer_1, integer_2 ]
HISTORY := integer

Parameter:

integer, integer_1, integer_2    --  non-negative integer

Summary:

HISTORY gives the length of the history table. HISTORY also gives the number
of results that can subsequently be accessed with last:

 o  If the value of HISTORY is given as a list of two integers then the first
    integer gives the length of the history table on the interactive leveland
    the second gives the length of the table in procedures.

 o  If only one integer is given as the value of HISTORY then its meaning
    is dependent on the current context. If the assignment is given on the
    interactive level then the integer gives the length of the history table on
    the interactive level. However, if the assignment is given in a procedure
    then this sets the length of the history table for procedures.

With the assignment HISTORY := NIL;, HISTORY is set to its default value

of [20, 3]. The highest possible value for both components of HISTORY is
231-1. HISTORY is an environment variable.


>>  f := proc() local HISTORY; begin
        HISTORY := 5; a; b; c; d; e; last(5)
    end_proc:
    f();

      a

See also:

history , last
