Added string-from-ptr example.

-- Response to a question asked by Thaddeus L. Olczyk


git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@5489 626c5289-ae23-0410-ae9c-e8d60b6d4f22

SWIG/Examples/ocaml/string_from_ptr/Makefile

@@ -0,0 +1,34 @@
+TOP        = ../..
+SWIG       = $(TOP)/../swig
+SWIGOPT    = -c++
+SRCS       = 
+TARGET     = example
+INTERFACE  = foolib.i
+MLFILE     = foolib.ml
+PROGFILE   = example_prog.ml
+OBJS       = 
+
+all:: static static_top
+
+static::
+	$(MAKE) -f $(TOP)/Makefile SRCS='$(SRCS)' SWIG='$(SWIG)' \
+	SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' \
+	MLFILE='$(MLFILE)' PROGFILE='$(PROGFILE)' OBJS='$(OBJS)' \
+	ocaml_static_cpp
+
+static_top::
+	$(MAKE) -f $(TOP)/Makefile SRCS='$(SRCS)' SWIG='$(SWIG)' \
+	SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' \
+	MLFILE='$(MLFILE)' PROGFILE='$(PROGFILE)' OBJS='$(OBJS)' \
+	ocaml_static_cpp_toplevel
+
+dynamic::
+	$(MAKE) -f $(TOP)/Makefile SRCS='$(SRCS)' SWIG='$(SWIG)' \
+	SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)'
+	MLFILE='$(MLFILE)' PROGFILE='$(PROGFILE)' OBJS='$(OBJS)' \
+	ocaml_dynamic_cpp
+
+clean::
+	$(MAKE) -f $(TOP)/Makefile MLFILE='$(MLFILE)' ocaml_clean
+
+check: all

SWIG/Examples/ocaml/string_from_ptr/example_prog.ml

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+(* foo_program.ml -- the program using foolib *)
+
+open Swig    (* Give access to the swig library *)
+open Foolib  (* This is the name of your swig output *)
+
+let results = _foo '()  (* Function names are prefixed with _ in order to make
+			   them lex as identifiers in ocaml.  Consider that
+			   uppercase identifiers are module names in ocaml.
+			   NOTE: the '() syntax is part of swigp4.  You can do:
+		           let results = _foo C_void *)
+
+(* Since your function has a return value in addition to the string output,
+   you'll need to match them as a list *)
+
+let result_string =
+  match results with 
+    C_list [ C_string result_string ; C_int 0 ] -> (* The return value is
+	last when out arguments appear, but this too can be customized.
+	We're also checking that the function succeeded. *)
+      result_string
+  | _ -> raise (Failure "Expected string, int reply from _foo")
+      
+let _ = print_endline result_string

SWIG/Examples/ocaml/string_from_ptr/foolib.i

@@ -0,0 +1,16 @@
+%module foolib
+%{
+static int foo( char **buf ) {
+  *buf = "string from c";
+  return 0;
+}
+%}
+
+%typemap(in,numinputs=0) char **buf (char *temp) {
+    $1 = &temp;
+}
+%typemap(argout) char **buf {
+    swig_result = caml_list_append(swig_result,caml_val_string((char *)*$1));
+}
+
+int foo( char **buf );