## 8.4 Local opens for patterns

(Introduced in OCaml 4.04)

pattern | ::= | ...
| ∣ | module-path .( pattern )
| ∣ | module-path .[ pattern ]
| ∣ | module-path .[| pattern |]
| ∣ | module-path .{ pattern }

For patterns, local opens are limited to the module-path .( pattern ) construction. This construction locally open the module referred to by the module path module-path in the scope of the pattern pattern.

When the body of a local open pattern is delimited by [ ], [| |], or { }, the parentheses can be omitted. For example, module-path .[ pattern ] is equivalent to module-path .([ pattern ]), and module-path .[| pattern |] is equivalent to module-path .([| pattern |]).