[go-nuts] Arithmetic operations inside of html/template

You can bind funcs to the template. See spec below and (a bit lower) an
example.
http://golang.org/pkg/text/template/#FuncMap

Thanks, I saw that, but I feel a bit weird adding so much boilerplate for
adding one to a number :-/

It's not that bad.

http://play.golang.org/p/4zgALysuoE

It's a slippery slope thing. Sure, +1 is easy but then you want *2 and
then <<3 and then switch and then closures and so on. Unlike with
templates in other languages, I deliberately chose not to provide a
full programming language, and ask the programmer to use the one
that's already there.

Functions are underappreciated. In general, not just in templates.

-rob

--

Possibility remains to beef up the builtins, and/or export a select subset
(e.g. truth -> Truth) as helpers at the package level. The example just
posted is not doing any type checking, etc. as it
should<http://golang.org/src/pkg/text/template/funcs.go#L143>.
I think end users would benefit from a refactored length to call a
Container (akin to truth) that can be used to build up their specific
required funcs. "Batteries included".

--

It's not even that bad. You can just return the number:

http://play.golang.org/p/X7iTnJ5Nrm

You can even use a simpler, more general function which you can then
compose with other functions to get the same result:

http://play.golang.org/p/jEA_red64E

--

I actually agree with minimizing the power of the expressions you could use
on templates. I don't want to end up writing php-like templates.

Thanks for your solutions, I actually ended up creating a new method on the
object I was passing generating the value I wanted, which is pretty similar
to what you proposed, but I avoid adding functions to the map.

Thanks!