Spin Syntax Question...

jmspaggi

Hi all,

I'm sure there is a super clean do to what I'm looking for...

Here is the code

bytemove (lf_number_addr+index, @sd_buffer+cursor, strsize(@sd_buffer+cursor)+1)

What I want to do is to transfert only a certain amount for memory. if strsize(@sd_buffer+cursor)+1 is bigger than 30, I want to limit it to 30. I can put a if before, but is there another way to do something like

bytemove (lf_number_addr+index, @sd_buffer+cursor, strsize(@sd_buffer+cursor)+1>30?30:strsize(@sd_buffer+cursor)+1)

This is Java syntax. Not sure for Spin...

Thanks,

JM

Mike Green

There is no equivalent to the "? :" operator. In your case, you're just doing a maximum calculation and there is an operator for that situation. Check out the description for the "<#" operator in the Propeller Manual.

You could use something like: (strsize(@s)+1)<#30

jmspaggi

Super, thanks a lot! That's exactly what I was looking for. Even beter than the ? syntax for this situation

JM

Page 155 of the manual:

Limit Maximum ‘<#’, ‘<#=’
The Limit Maximum operator compares two values and returns the lowest value. Limit Maximum can be used in both variable and constant expressions. Example:
X := Y + 21 <# 250
The above example adds 21 to Y and limits the result to a maximum value to 250. If Y is 200 then 200 + 21 = 221; it is less than 250 so X is set to 221. If Y is 240 then 240 + 21 = 261; it is greater than 250 so X is set to 250 instead.
Limit Maximum has an assignment form, <#=, that uses the variable to its left as both the first operand and the result destination. For example,
X <#= 50 'Short form of X := X <# 50
Here, the value of X is limited to a maximum value of 50 and the result is stored back in X. The assignment form of Limit Minimum may also be used within expressions for intermediate results; see Intermediate Assignments, page 147