This is the correct behavio of regular expressions. Anyway, good that you are pointing this out since others may find it counter intuitive.
Massimo On Feb 2, 6:33 pm, Ken <[email protected]> wrote: > I have been having trouble with truncation of data from one field of a > form. The culprit turned out to be the IS_MATCH() validator, which was > truncating a valid value to return a shorter valid value. I'm not sure > whether to call this a bug or just unexpected behavior, but if I had > trouble with it, someone else may. > > The data in question were spreadsheet-style coordinate values with > letters for rows and numbers for columns, in the range A1 to J10. > Initially, I used a validator like IS_MATCH('^[A-J][1-9]|[A-J]10$'). > This checks first for the two-character combinations A1 to J9, then > checks for A10 to J10. If I test this in a web2py shell, it accepts > and returns the two-character combinations, but it accepts and > truncates any values ending in 10. > > In [1] : vdtr = IS_MATCH('^[A-J][1-9]|[A-J]10$') > > In [2] : vdtr('A1') > ('A1', None) > > In [3] : vdtr('J1') > ('J1', None) > > In [4] : vdtr('A10') > ('A1', None) > > In [5] : vdtr('J10') > ('J1', None) > > It seems to me that A1 and J1 are not proper matches because the '1' > does not appear at the end of the validated string. In any case, I am > surprised that IS_MATCH() would modify a value under any > circumstances. > > If I turn the regex around, so that it tests for the three-character > combinations first, like IS_MATCH('^[A-J]10|[A-J][1-9]$'), then things > work better. > > In [6] : vdtr = IS_MATCH('^[A-J]10|[A-J][1-9]$') > > In [7] : vdtr('A1') > ('A1', None) > > In [8] : vdtr('J1') > ('J1', None) > > In [9] : vdtr('A10') > ('A10', None) > > In [10] : vdtr('J10') > ('J10', None)
