sexp_of_lazy_t

CHANGELOG.md

@@ -6,6 +6,7 @@
 - `forget_printbox`
 - `snapshot` in the PrintBox backend as in [#21](https://github.com/lukstafi/ppx_minidebug/issues/21).
 - Optionally, `snapshot ()` at the end of a `log_value` call if elapsed time since last snapshot is greater than given threshold.
+- A replacement `Minidebug_runtime.sexp_of_lazy_t` that does not force the thunk (but prints content if available).
 
 ### Changed
 

minidebug_runtime.ml

@@ -893,3 +893,7 @@ let debug_flushing ?debug_ch:d_ch ?filename ?(time_tagged = false)
   (module Flushing ((val log_to)))
 
 let forget_printbox (module Runtime : PrintBox_runtime) = (module Runtime : Debug_runtime)
+
+let sexp_of_lazy_t sexp_of_a l =
+  if Lazy.is_val l then Sexplib0.Sexp.List [ Atom "lazy"; sexp_of_a @@ Lazy.force l ]
+  else Sexplib0.Sexp.List [ Atom "lazy"; Atom "<thunk>" ]

minidebug_runtime.mli

@@ -248,3 +248,7 @@ val debug_flushing :
 
 val forget_printbox : (module PrintBox_runtime) -> (module Debug_runtime)
 (** Upcasts the runtime. *)
+
+val sexp_of_lazy_t : ('a -> Sexplib0.Sexp.t) -> 'a lazy_t -> Sexplib0.Sexp.t
+(** Unlike [Lazy.sexp_of_t] available in the [Base] library, does not force the lazy value,
+    only converts it if it's already computed and non-exception. *)