-external get_sv : ?create:bool -> string -> sv = "perl4caml_get_sv"
-(** Return a scalar value by name. For example, if you have a symbol
- * called [$a] in Perl, then [get_sv "a"] will return its value.
- *
- * If the symbol does not exist, this throws [Not_found].
- *
- * If the optional [?create] argument is set to true and the symbol does
- * not exist, then Perl will create the symbol (with value [undef]) and
- * this function will return the [SV] for [undef].
+val hv_empty : unit -> hv
+(** Create an empty [HV] (hash). *)
+val hv_set : hv -> string -> sv -> unit
+(** Store the given [SV] in the named key in the hash. *)
+val hv_get : hv -> string -> sv
+(** Return the [SV] at the key in the hash. Throws [Not_found] if no key. *)
+val hv_exists : hv -> string -> bool
+(** Return true if the hash contains the given key. Same as Perl [exists]. *)
+val hv_delete : hv -> string -> unit
+(** Delete the given key from the hash. Same as Perl [delete]. *)
+val hv_clear : hv -> unit
+(** Remove all elements from the [HV]. Same as Perl [%av = ()]. *)
+val hv_undef : hv -> unit
+(** Delete the [HV] (and all elements in it). Same as Perl [undef %hv]. *)
+val hv_of_assoc : (string * sv) list -> hv
+(** Create an [HV] directly from an assoc list. Perl hashes cannot
+ * support multiple values attached to the same key, so if you try
+ * to provide an assoc list with multiple identical keys, the results
+ * will be undefined.
+ *)
+val assoc_of_hv : hv -> (string * sv) list
+(** Take an [HV] and return an assoc list. *)
+val hv_keys : hv -> string list
+(** Return all the keys of an [HV]. *)
+val hv_values : hv -> sv list
+(** Return all the values of an [HV]. *)
+
+(* The following are the low-level iteration interface to hashes,
+ * which you probably shouldn't use directly. Use {!hv_keys},
+ * {!assoc_of_hv}, etc. instead. See [perlguts(3)] if you really
+ * want to use this interface.
+ *)
+type he
+val hv_iterinit : hv -> Int32.t
+val hv_iternext : hv -> he
+val hv_iterkey : he -> string
+val hv_iterval : hv -> he -> sv
+val hv_iternextsv : hv -> string * sv
+
+val get_sv : ?create:bool -> string -> sv
+ (** Return a scalar value by name. For example, if you have a symbol
+ * called [$a] in Perl, then [get_sv "a"] will return its value.
+ *
+ * If the symbol does not exist, this throws [Not_found].
+ *
+ * If the optional [?create] argument is set to true and the symbol does
+ * not exist, then Perl will create the symbol (with value [undef]) and
+ * this function will return the [SV] for [undef].