Fix documentation for how to compile using camlp4 directly.

[ocaml-bitstring.git] / bitmatch_persistent.mli

diff --git a/bitmatch_persistent.mli b/bitmatch_persistent.mli
index ce6399d..8c97a34 100644 (file)
--- a/bitmatch_persistent.mli
+++ b/bitmatch_persistent.mli
@@ -53,6 +53,19 @@ let is_pascal_string bits =
       str strlen
 v}
 
+   or:
+
+{v
+(* Load a persistent pattern from a file. *)
+open bitmatch "pascal.bmpp"
+
+let is_pascal_string bits =
+  bitmatch bits with
+  | \{ :pascal_string } ->
+    printf "matches a Pascal string %s, len %d bytes\n"
+      str strlen
+v}
+
    {3 Important notes}
 
    There are some important things you should know about
@@ -99,7 +112,7 @@ v}
 
    [bitmatch bits with { :name } -> ...]
 
-   You can use named patterns within named patterns.
+   You can nest named patterns within named patterns to any depth.
 
    Currently the use of named patterns is somewhat limited.
    The restrictions are:
@@ -275,7 +288,8 @@ and alt =
 
 val string_of_pattern : pattern -> string
 val string_of_constructor : constructor -> string
-val string_of_field : 'a field -> string
+val string_of_pattern_field : patt field -> string
+val string_of_constructor_field : expr field -> string
 (** Convert patterns, constructors or individual fields
     into printable strings for debugging purposes.
 
@@ -316,7 +330,7 @@ val create_pattern_field : loc_t -> patt field
 
     The pattern is unbound, the type is set to [int], bit length to [32],
     endianness to [BigEndian], signedness to unsigned ([false]),
-    and source code location to the [_loc] parameter.
+    source code location to the [_loc] parameter, and no offset expression.
 
     To create a complete field you need to call the [set_*]
     functions.  For example, to create [{ len : 8 : int }]
@@ -409,6 +423,23 @@ val set_location : 'a field -> loc_t -> 'a field
 (** Sets the source code location of a field.  This is used when
     pa_bitmatch displays error messages. *)
 
+val set_offset_int : 'a field -> int -> 'a field
+(** Set the offset expression for a field to the given number.
+
+    The effect is that the field [{ _ : 8 : offset(160) }] could
+    be created by calling [set_offset_int field 160]. *)
+
+val set_offset : 'a field -> expr -> 'a field
+(** Set the offset expression for a field to the given expression.
+
+    The effect is that the field [{ _ : 8 : offset(160) }] could
+    be created by calling [set_offset_int field <:expr< 160 >>]. *)
+
+val set_no_offset : 'a field -> 'a field
+(** Remove the offset expression from a field.  The field will
+    follow the previous field, or if it is the first field will
+    be at offset zero. *)
+
 (** {3 Create constructor fields}
 
     These fields are used in constructors ([BITSTRING]). *)
@@ -472,3 +503,6 @@ val get_type : 'a field -> field_type
 
 val get_location : 'a field -> loc_t
 (** Get the source code location of a field. *)
+
+val get_offset : 'a field -> expr option
+(** Get the offset expression of a field, or [None] if there is none. *)