Shame that i can't remember anymore all my reasons for wanting those "getAs<Type>" lookups. Wondering why getAsNumber and getAsBoolean are here too. Anyone else recall the use case? And assuming that i had good reason (that did happen sometimes <grin>), i wonder why i pushed for bucking the "to<Type>()" convention.
As for the literals, the thought of them being used in #if statements in a template language is cringe-inducing. What's the use-case? Temporary debugging hacks? If so, part of me thinks maybe only 'true' should even be allowed. On Sat, Jan 28, 2017 at 7:15 AM, Claude Brisson <cla...@renegat.net> wrote: > > >>>> What is the problem? >>>> >>>> Velocity "truthiness": >>> https://issues.apache.org/jira/browse/VELOCITY-692 >>> >>> It should definitely be part of 2.0. I missed it because the issue was >>> closed, we should have opened a 2.0 one to remember it. >>> >> >> Thats's the problem if a closed/resolved issue does not have an >> assignee. You never know who handled it without reading the entire >> thread. A ticket should always have an assignee if code has been changed. >> >> > Here's what had been specified by Nathan at the time (order is meaningful, > and falseness seems easier to specify than truth): > > $obj is null > $obj is boolean false > $obj returns false from getAsBoolean() (provided there is such a method) > $obj is empty string (CharSequence w/length 0) > $obj returns true from isEmpty() (provided there is such a method) > $obj is array of length 0 > $obj returns null from getAsString() (provided there is such a method) > $obj returns empty string from getAsString() (provided there is such a > method) > $obj returns null from getAsNumber() (provided there is such a method) > $obj returns 0 from length() or size() (provided there is such a method) > $obj returns empty string from toString() (provided there is such a method) > > Regarding this spec: > - I'm not sure about getAsString() ; toString() is usually the standard > way of getting the String representation and should be enough. > - I'm not convinced by the fact that zero should be true. I hear Nathan's > point that for a display language, zero is as legitimate as any other > number to be displayed. But it breaks the principle of least surprise, > since each and every other language around, when not forbidding number > towards boolean implicit conversion, consider zero as false. > > So I'd rather go with: > > $obj is null > $obj is Boolean false > $obj is Number zero (whatever Number variant) > $obj returns false from getAsBoolean() (provided there is such a method) > $obj is empty string (CharSequence w/length 0) > $obj returns true from isEmpty() (provided there is such a method) > $obj is array of length 0 > $obj returns null from getAsNumber() (provided there is such a method) > $obj returns 0 from length() or size() (provided there is such a method) > $obj returns empty string from toString() (provided there is such a method) > > Also, I noticed that Velocity weren't very consistent with literals. The > only literal returning true is the 'true' literal. "foo" is false, whereas > it should be consistent with $foo containing "foo". > > Claude > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@velocity.apache.org > For additional commands, e-mail: dev-h...@velocity.apache.org > >
