Laura Demkowicz-Duffy (Jun 10 2023 at 23:24): Laura Demkowicz-Duffy (Jun 10 2023 at 23:24):I have some code which tends to hand without exiting or responding a lot of the time it's run (the code path it takes is random), and upon Ctrl-C'ing it or similar, I tend to find the top of the stacktrace looks like this:
The code in question here is:
"""
cityindexunchecked(world, id)
Get the index of a [`City`](@ref) into `world.cities` and `world.graph` from it's `id`.
Returns `nothing` if the city isn't found.
"""
function cityindexunchecked(world, id)
findfirst(c -> c.id == id, world.cities)
end
# Convenience method:"Los Angeles", ["San Francisco", "Chicago", "Mexico City", "Sydney"]),
# integers are not valid ids so we assume c is the index and return it
cityindexunchecked(world, id::Int) = id
cityindexunchecked(world, c::City) = cityindexunchecked(world, c.id)
"""
cityindex(world, city[, error])
Get the index of a [`City`](@ref) into `world.cities` and `world.graph` from it's `id`.
Throws an error if the city isn't found.
Pass the parameter `error` to override the error text.
`id` may either be a [`City`](@ref) object or just some identifying object.
"""
function cityindex(world, c, e = "City $c not found")
i = cityindexunchecked(world, c)
@assert i != nothing e
return i
end
export cityindex
Can this be the result of the potential string comparison in cityindexunchecked? The type of id is typically a string.
mbaz (Jun 11 2023 at 00:37):My first guess would be that the culprit is the$c in cityindex
Sukera (Jun 11 2023 at 06:08):the stacktrace has cityindex:62, which is likely where your function definition originally is?
Sukera (Jun 11 2023 at 06:09):if so, yes, the interpolation ALWAYS happens, not just when the error is thrown
Sukera (Jun 11 2023 at 06:11):note also the docstring of @assert:
│ Warning
│
│ An assert might be disabled at various optimization levels. Assert should therefore only be used as a
│ debugging tool and not used for authentication verification (e.g., verifying passwords), nor should
│ side effects needed for the function to work correctly be used inside of asserts.
So at various optimization levels, the @assert may be removed entirely, leading to a wrong result. I'd suggest the pattern
isnothing(i) || throw(ArgumentError(LazyString("City ", c, " not found"))
which will stay in your code across optimization levels and only interpolate the string when the error is actually thrown.
Notification Bot (Jun 11 2023 at 11:31):Laura Demkowicz-Duffy has marked this topic as resolved.
Notification Bot (Jun 11 2023 at 11:31):Laura Demkowicz-Duffy has marked this topic as resolved.
Last updated: Dec 28 2024 at 04:38 UTC