The Law of Leaky Abstractions (2002)
joelonsoftware.com1 pointsby SmartHypercube0 comments
- Start at the range of 0-F, measure the score of 6 and 9 (2 tries)
- Depending on which is higher, narrow the range to 0-9 or 6-F
- Suppose the range is 0-9, measure the score of 3 and 6 (1 try. 6 is already measured)
- Narrow the range to 0-6 or 3-9
- Suppose the range is 0-6, measure the score of 2 and 3 (1 try. 3 is already measured)
- The worse case is 3's score is higher. The range is now 2-6. Since 2, 3, 6 are all measured, in the worst case you need 2 more tries for 4 and 5.
- The other case is 2's score is higher. The range is now 0-3 and 0, 2, 3 are all measured.
SQLite supports a set of JSON functions that let you query and index JSON columns directly, which looks very convenient—but be careful:
1. `json('{"a/b": 1}') != json('{"a\/b": 1}')`
Although the two objects are identical in terms of JSON semantics, SQLite treats them as different.
2. `json_extract('{"a\/b": 1}', '$.a/b') is null`, `json_extract('{"\u0031":1}', '$.1') is null`, `json_extract('{"\u6211":1}', '$.我') is null`
This issue only exists in older versions of SQLite; the latest versions have fixed it.
In many cases you can't control how your JSON library escapes characters. For example, `/` doesn’t need to be escaped, but some libraries will escape it as `\/`. So this is a rather nasty pitfall, you can end up failing to match keys during extraction with seemingly no reason.