Bronze Edition Guide - True BASIC

154 BRONZE Edition Guide
DEF Structure
DEF identifier (parm1, ..., parm n)
...
EXIT DEF [optional]
...
END DEF
The DEF structure input order allows the programmer to define new multi-line functions.
The DEF structure may contain one or more EXIT DEF statements.
The function is invoked by including its name, with suitable arguments, in an expression.
The arguments must match the parameters in the DEF structure in number, position, type,
and number of dimensions. Parameter passing is by value; that is any changes to the
parameters will not cause changes to the corresponding arguments.
The defined function can also contain DECLARE DEF and LOCAL statements.
DIM Statement
DIM array (bounds), ..., array (bounds)
Except for function or subroutine parameters, each array in a program-unit must be dimensioned
in a DIM or LOCAL statement that occurs lexically before the first reference to that
array.
DO Loop
DO { | WHILE condition | UNTIL condition | }
. . .
EXIT DO [optional]
. . .
LOOP { WHILE condition | UNTIL condition | }
The DO statement can contain either a WHILE or UNTIL part, or nothing, and the same
for the LOOP statement. There can be any number of EXIT DO statements.
DRAW Statement
DRAW picture name (arg 1, ..., arg n)
DRAW picture name (arg 1, ..., arg n) WITH trans *... * trans
trans:: SCALE (size)
SCALE (xsize, ysize)
ROTATE (angle)
SHIFT (xshift, yshift)
SHEAR (angle)
The (argument-list) is optional. The DRAW statement causes the picture named to be drawn