ppx_optional
Pattern matching on flat options
README
A ppx rewriter that rewrites simple match statements with an if then
else expression.
Syntax
ppx_optional
rewrites the extension match%optional
in expressions.
It requires that a module Optional_syntax
is in scope, and that it
has is_none
and unsafe_value
values.
For instance:
match%optional e with
| None -> none_expression
| Some x -> some_expression
becomes:
if Optional_syntax.is_none e then begin
none_expression
end else begin
let x = Optional_syntax.unsafe_value e in
some_expression
end
Usage
This is normally used to safely access an optional value while
avoiding allocation for immediate values
(e.g. Immediate.{Char,Bool,Int}.Option
, Fixed.Option
,Price.Fixed.Option
, etc...).
Install
- Published
-
21 Mar 2022
- Authors
-
- Maintainers
-
Sources
Dependencies
Reverse Dependencies
ppx_jane
>= "v0.15.0"