Use another language to call a function: Difference between revisions

=={{header|Ada}}==

The interface package Exported specification:

with Interfaces.C.Strings; use Interfaces.C.Strings;

 

return int;

pragma Export (C, Query, "Query");

The package implementation:

function Query (Data : chars_ptr; Size : access size_t)

return int is

end if;

end Query;

With [[GNAT]] it can be built as follows:

gnatmake -c exported.adb

gnatbind -n exported.ali

Sample output:

<pre>

=={{header|HaXe}}==

=== PHP ===

 

=={{header|Lisaac}}==

query.li

 

+ name := QUERY;

+ size : NATIVE_ARRAY[INTEGER];

query(buffer, size); // need this to pull the query() method

Makefile

 

all: $(TARGET)

 

clean:

 

=={{header|OCaml}}==

#include <string.h>

#include <caml/mlvalues.h>

;;</lang>

 

gcc -c main.c -I"`ocamlc -where`"

gcc -o prog.opt main.o caml_part_obj.o \

===‘In’ Parameters===

To connect a function to Tcl that passes an arbitrary C string as input, you'd use a short C thunk, like this:

Tcl_Obj *arguments[2];

int code;

===‘Out’ Parameters===

However, in the specific case of writing to a user-specified buffer (an “out” parameter) the thunk code would instead manage copying the result from the interpreter back to the buffer:

const char *str;

int len;

===Connecting up the pieces===

You would also need a short piece of code in <code>main()</code> to initialize the Tcl library and create an interpreter instance, and you would need to build and link against [[libtcl]].

Tcl_Interp *interp;