Sounds good to me.
+1
Cheers,
Till
On 29 Jan 2018, at 18:54, Dmitry Lychagin wrote:
All,
We would like to change how string functions count character positions
inside a string.
Currently string functions position(), substring() and some others
assume that the first character is at position 1.
The proposal is to change the first position to 0, to better align
with array element positions (which also start with 0), and other
languages (JavaScript, etc).
This change will also apply to binary functions (see below) and will
be effective in both SQLPP and AQL.
The following functions will be affected:
position(),
regexp_position(),
substring()/substr(),
sub_binary(),
find_binary()
This might be a disrupting change for some users so we will also
introduce a cluster-wide configuration parameter
(“compiler.stringoffset”) for backwards compatibility:
compiler.stringoffset = 0 // first character position is assumed to
be 0 (new default)
compiler.stringoffset = 1 // first character position is assumed to
be 1 (backwards-compatible setting)
The query migration path is straightforward, for example:
substring(“abcdef”, 1) will need to be changed to
substring(“abcdef”, 0), etc, same applies to sub_binary().
position(), regexp_position(), and find_binary() will return one less
than they used to, but would still return -1 if the value is not
found.
Please share your comments and concerns.
Thanks,
-- Dmitry
