escapes in symbols

[kowey]

This is already present as a TODO in the source code, but I thought maybe an issue would be useful to track it and put some notes down.

As I understand it, we would need to worry about 3 things: single escape characters (, with NB \n meaning 'n' and not 'newline char'), multi-escape characters (|Jurassic Park|), and package markers (Films::|Jurassic Park|).

Package markers may be tricky. We may need to change from Symbol Text to Symbol (Maybe Text) Text. So

• |Jurassic Park| becomes Symbol Nothing "Jurassic Park",
• :title becomes Symbol (Just "KEYWORD") "title", and
• Films::|Jurassic Park| becomes Symbol (Just "Films") "Jurassic Park".

Alternatively, a package marker type, which may be less yucky than having the "KEYWORD"convention (technically true as it may be, IIUC correctly, they do literally go into the KEYWORD package)

Some random/not-too-useful self-expression: I like the HyperSpec, but find it quite confusing to navigate. I think I wish it had fewer hyperlinks, and they all pointed to the spec itself instead of the glossary

[nominolo]

Or instead of Symbol Text we use Symbol SymbolName where:

data SymbolName = Unqual Text | Keyword Text | Qualified PackageName Text

type PackageName = [Text]   -- or just Text

Note also that foo:bar is also a qualified symbol name (though bar must be exported from package foo).

I'm a bit unsure whether atto-lisp should support all of Common Lisp`s special (lexical) features or just stuff that's common among different types of Lisps (including Clojure, Emacs Lisp, Scheme, Racket, ...).

[kowey]

Something else I was just thinking about. If we want escapes, we may have to consider how we distinguish between characters that are case-insensitive and those with a fixed case (ugh).

One approach (not necessarily a good one), would be instead of representing symbol names as Text to using something more like [Morsel] with data Morsel = Insensitive Text | Sensitive Text.

Sigh! (This doesn't affect me by the way, just something that came up. Only thing that does affect me is I think that NIL isn't recognised as nil; but I'll need to reproduce that to be sure).