inconsistent treatment of negative 0 #95
Description
The tests have inconsistent requirements for negative zero.
Negative zero in an index selector is invalid:
{
"name": "index selector, -0",
"selector": "$[-0]",
"invalid_selector": true,
"tags": [
"index"
]
},Negative zero in a filter selector must be handled as zero:
{
"name": "filter, equals number, negative zero and zero",
"selector": "$[[email protected]==-0]",
"document": [
{
"a": 0,
"d": "e"
},
{
"a": 0.1,
"d": "f"
},
{
"a": "0",
"d": "g"
}
],
"result": [
{
"a": 0,
"d": "e"
}
]
},Why?
This inconsistency makes the parser code more complicated.
- can't just raise an error when the lexer sees "-0", because it might be OK
- have to defer that decision to the parsing stage and decide whether the -0 is inside an index selector, which is a pain.
Personally I would prefer to just allow negative zero. It's harmless, easy to parse and most "real" languages allow it.
If you are writing a parser that is good enough to detect this error, it is just as easy to treat it as positive zero and move on.