array-indexing.md

+## Array Indexing
+
+
+Array indexing currently uses the `!` infix operator.  However, `!` is also used by the [BangPatterns](bang-patterns) proposal, which leads to some interesting parsing issues if you try to combine the two (parterns are usually parsed as expressions in Haskell due to ambiguities).
+
+
+Furthermore, it seems more consistent to reserve `!` to mean "strict", which it does in other contexts: constructor field declarations, the `$!` operator, and [BangPatterns](bang-patterns).  Later we might want to introduce `!` as a general type operator.
+
+
+If we remove `!` as array indexing, what do we use instead?  If the [CompositionAsDot](composition-as-dot) proposal is adopted, then that leaves `.` free to be used for "selection", and array indexing is definitely a form of selection, so perhaps one of the following syntaxes would be appropriate:
+
+```wiki
+  array.(i)
+```
+
+
+This is unambiguous if `e.x` is to be used for record field selection.  An arbitrary expression would of course be allowed inside the parentheses.
+
+```wiki
+  array.[i]
+```
+
+
+Also unambiguous, but inconsistent with the use of `[]` for lists.
+
+```wiki
+  array.#i
+```
+
+
+This doesn't even require any new syntax, because `.#` is a valid infix operator.