Thank you. The gist works well.
In situations when I have to use a for loop, is there a way to tell if
the for loop has completed or not?
Wai Yip
Gray Calhoun <mailto:[email protected]>
Friday, January 30, 2015 3:25 PM
You can use a macro. I've written short-circuiting 'any' and 'all'
macros that are available in this gist:
https://gist.github.com/grayclhn/5e70f5f61d91606ddd93
I'm sure they can be substantially improved; the usage would be
||
if@all[f(x)forx in1:1000000000000000000000000000000000]
## success
else
## failure
end
and it rewrites the list comprehension as a loop and inserts a break
statement
On Friday, January 30, 2015 at 12:51:13 AM UTC-6, Wai Yip Tung wrote:
Wai Yip Tung <mailto:[email protected]>
Thursday, January 29, 2015 10:51 PM
I want to apply function f() over a range of value. f() returns true
for success and false for failure. Since f() is expensive, I want
short circuit computation, i.e. it stops after the first failure.
In python, I can do this in an elegant way with the all() function and
generator expression.
if all(f(x) for x in values)
# success
else
# failure
From what I understand, there is no generator expression in Julia.
List comprehension will evaluate the full list. Even if I try to use
for loop, I can't use the control variable to check if the loop has
run to finish or not.
i = 0
for i in 1:length(values)
if !f(values[i])
break
end
end
# The status is ambiguous if i==length(values)
My last resort is to add flags to indicate if is success or not. Is
there some more elegant way to do this?
