if command with no comparison

TJHJ

So I was looking at the TSL230 light to frequency driver, and for the auto scaling part, in which it changes the state of two pins to determine the scale.
The command call, places a true or false in auto.·
So it then evaluates the following

if auto                                               'autoscaling code
    if val > 1_000_000                                  'if output exceeds 1 MHz, decrease gain
      scale := --scale #> 1
    elseif val < 10_000                                 'if output less than 10 kHz, increase gain
      scale := ++scale <# 3
    outa := scale << cbase

changing which pins are high/low to set the scale. So where I am lost is in the if evaluation. I just had it in my mind a if statement it must be followed by a evaluation.

I am guessing that if auto == true it performs the evaluation?

False does nothing, leaving the two output pins as they were previously set.·I just wanted to make sure this is correct?

Mike Green

The IF must be followed by an expression. If the expression evaluates to a non-zero value, the IF clause is executed, otherwise the ELSE (or ELSEIF) clause is executed. Read the documentation on the IF statement.

"if auto" is equivalent in behavior to "if auto <> 0"