[Grace-core] comments from visit to eelco, vlad & co at Delft

[James Noble]

Hi all,

so Kim & I visited Eelco's group at Delft for the last couple of days.
Most of the time was spent on the detail of the grammar & operational
semantics for various SPOOFAX tools.  There were some 
"suggestions" (or mostly "reminders") that came out of the discusison


* we need to decide: are typeExpressions just expressions?

* the "you can omit the "type" keyword" rule on type declarations -- causes ambiguity (blocks vs type literals)

* Eelco likes the idea of a "semicolon inserter"  that takes layout grace and inserts the semicolons and prints it out again
  at least we could use it to convert test suites from full minigrace to e.g. systems that need semicolons

* what should go in the prelude?   how does it work with primitives?  can we just say "everything is in the prelude"

* combinator grammar currently misses dialect, import, annotations (and outer)
* combinator grammar  should lose list literal syntax

=========

And a reminder - a list of language changes we're contemplating:

* outer to work much like super (but up the lexical chain) - not denoting objects, just directing "lookup" 

* generic character < >   or [[ ]] or  [|  |]  ?    ?????
    we quite like [[ ]] but it looks terrible in Monaco or a monospaced font.
    Gill Sands looks good for most thing *except* the arrows -> <- 

* CLASS SYNTAX to DOT or not to DOT: that is the question!