[stringtemplate-interest] it, i, i0 for ST v4

[Terence Parr]

hiya! So, v4 is going to require template argument defs like:

bold(x) ::= "<b>$b$</b>"

That means that "it" iteration value is not necessary; we'll define an arg:

<names:{ n | hi <n>}>

Dynamic scoping means we can see all the way up the enclosing template chain. That means we might see an "it" we don't expect.  A few recent posts about how to get at the correct version of "it" in nested templates.  problem solved.  you name the iteration value.

BUT, we still need i and i0 integer indexes.  Same issue. 

<names:{ n | <i>. <n>}>

gives

1. Ter
2. Tom
3. Sri
...

Perhaps they are only defined by those lambda-like anonymous templates?  It's weird/confusing if you can see i in another template:

<names:foo()>

then:

foo(n) ::= "<i>. <n>" // where does i come from!??!

What about NESTED templates though?  Here is how to dump out chapters and sections for a table of contents:

<chapters:{c | <i> Chapter <c.name> <c.sections:{s | <i><i>. <s.name>}>}>

But, what does "<i><i>" mean?  First i should be chapter.

Anybody have any ideas?  super.i is wrong. The only idea i had was to let people name the indexes, but how?

<chapters:{c,ci=i | <ci> Chapter <c.name> <c.sections:{s | <ci><i>. <s.name>}>}>

So, like a default argument value, we name our index so nested can see ci.

Hmm...that ain't bad I guess.  Any complaints?

Ter