Json module - SIGSEGV if key not exists

[scriptum]

This results in SIGSEGV:

import json
var data = parseJson("{\"a\":1,\"b\":2}")
echo data["a"]
echo data["c"]

Is that ok? Why not exception?

[Perelandric]

Traceback (most recent call last)
test.nim(38)             test
json.nim(990)            $
json.nim(759)            len
SIGSEGV: Illegal storage access. (Attempt to read from nil?)

Seems that it's from the len proc missing a nil check. The default when not given a jArray or jObject is to return 0, so I'd think it would be the same for nil.

[dom96]

I would rather be told that what I am passing to it is nil.

[scriptum]

Another strange behavior:

import tables
var a = newTable[string,string]()
echo a["b"] #nil
var b = newTable[string,int]()
echo b["c"] #0
b["c"] = 0
echo b["c"] #0 - same result: is key exist with value 0 or it doesn't exist?

Python throws exception in both cases.

[Perelandric]

I guess some len() procs handle nil and others don't. Weird.

@scriptum According to the docs, you get the default value for the type if no key exists, so this by design.