added Dpdl example for Native interface

DpdlLibs/native/dpdlNativeExample.h

@@ -0,0 +1,124 @@
+# File: native/dpdlNativeExample.h
+#
+# Example: Dpdl sample code that loads a native library (libc) and calls some functions
+#
+#			This code allocates memory via the native function 'malloc' , opens a file in read-write mode, write some values
+#			to the allocated buffer and writes the buffer to the file.
+#			The file is than re-opened in read only mode and the values are readed back and printed out.
+#
+# Author: A.Costa
+# e-mail: ac@dpdl.io
+#
+#
+import('native')
+
+# main
+println("Dpdl sample code that uses native function calls to 'libc'")
+
+println("loading 'libc' library...")
+
+object clib = native.loadLib("c")
+
+raise(clib, "Error in loading library")
+
+println("getting uid...")
+
+int uid = clib.getuid()
+println("uid: " + uid)
+
+println("opening file in RW mode for writing...")
+
+object fcntl = getClass("Fcntl")
+
+int fh = clib.open("./Test/TestWriteNative.txt", fcntl.O_RDWR)
+
+raise(fh, "Error in opening file")
+
+println("writing values...")
+
+int i = 3
+double d = 999.5d
+float f = 23.0
+long l = 10000000L
+
+char ch1 = 'X'
+char ch2 = 'D'
+char ch3 = 'P'
+char ch4 = 'D'
+char ch5 = 'L'
+char ch6 = 'X'
+char ch7 = '\0'
+
+object size = loadObj("size_t")
+size.setValue(4096L)
+
+long size_l = size.longValue()
+
+object memory = clib.malloc(4096)
+memory.setMemory(0L, 4096L, 0x00)
+
+println("memory: " + typeof(memory))
+
+object bytebuf = memory.getByteBuffer(0L, size_l)
+
+bytebuf.putInt(i)
+bytebuf.putDouble(d)
+bytebuf.putFloat(f)
+bytebuf.putLong(l)
+
+bytebuf.putChar(ch1)
+bytebuf.putChar(ch2)
+bytebuf.putChar(ch3)
+bytebuf.putChar(ch4)
+bytebuf.putChar(ch5)
+bytebuf.putChar(ch6)
+bytebuf.putChar(ch7)
+
+object sz = clib.write(fh, memory, size)
+
+println("nr of bytes written: " + sz)
+
+clib.close(fh)
+
+println("reading from file...")
+
+fh = clib.open("./Test/TestWriteNative.txt", fcntl.O_RDONLY)
+
+memory.setMemory(0L, 4096L, 0x00)
+
+object szr = clib.read(fh, memory, size)
+
+println("nr of bytes read: " + szr)
+
+object bufread = memory.getByteBuffer(0L, size_l)
+
+object ri = bufread.getInt()
+object rd = bufread.getDouble()
+object rf = bufread.getFloat()
+object rl = bufread.getLong()
+
+object rch1 = bufread.getChar()
+object rch2 = bufread.getChar()
+object rch3 = bufread.getChar()
+object rch4 = bufread.getChar()
+object rch5 = bufread.getChar()
+object rch6 = bufread.getChar()
+
+println("values from file: ")
+println("")
+println("ri: " + ri)
+println("rd: " + rd)
+println("rf: " + rf)
+println("rl: " + rl)
+
+println("rch1: " + rch1)
+println("rch2: " + rch2)
+println("rch3: " + rch3)
+println("rch4: " + rch4)
+println("rch5: " + rch5)
+println("rch6: " + rch6)
+
+clib.close(fh)
+
+println("")
+println("finished")

Dpdl_Examples.md

@@ -47,10 +47,11 @@ The Dpdl sample scripts and Dpdl sample applications published on this repositor
 
 ## Dpdl sample Apps
 
-More ddvanced sample applications written with Dpdl are published in this repository:
+More advanced sample applications written with Dpdl are published in this repository:
 
 [Dpdl-sample-Apps](https://github.com/Dpdl-io/Dpdl-sample-Apps)
 
+These examples are demonstrators but are full running applications.
 
 ## Dpdl examples
 
@@ -157,6 +158,10 @@ The code above automatically generated the following Dpdl code: [ai/dpdlAICodeSo
 
 	[dpdlPointers.h](https://github.com/Dpdl-io/DpdlEngine/blob/main/DpdlLibs/dpdlPointers.h)
 
+* Example Dpdl code that writes and reads a data buffer to a file using the native library functions in 'libc'
+
+	[native/dpdlNativeExample.h](https://github.com/Dpdl-io/DpdlEngine/blob/main/DpdlLibs/native/dpdlNativeExample.h)
+
 * Example Dpdl script embedding ANSI C code (ISO C99) that is dynamically compiled in memory at runtime (fast) and executed
 
 	[C/dpdlCcompileExample.h](https://github.com/Dpdl-io/DpdlEngine/blob/main/DpdlLibs/C/dpdlCcompileExample.h)

README.md

@@ -34,7 +34,7 @@ A dedicated Dpdl language plug-in (**DAN**) allows via <ins>**generative AI code
 These features make Dpdl a powerful development platform for rapid prototyping, in particular also due to the fact that software written with Dpdl will be enabled to access thousands of existing high-quality software libraries.
 Dpdl is not intended to replace, but to enable integration of different technologies seamlessly to leverage fast prototyping and foster research and development.
 
-**Dpdl is designed to:**
+## Dpdl is designed to:
 
 ### * Develop your ideas faster
 ### * On multiple platforms

doc/Dpdl_native_Interface.md

@@ -15,12 +15,32 @@ developed by
 
 Dpdl allows to access native library functions of any given loaded native library seamlessly, in the same way as ordinary dpdl functions.
 
-This features makes Dpdl a complete and powerful programming language to develop also low level system components.
+This features makes Dpdl a complete and powerful programming language to interact also with low level system components.
 
-By loading 'c' (see example below), Dpdl automatically selects the appropriate library, on Linux/Unix/MAC 'libc' and on Windows 'msvcrt'.
+**Dpdl library:**
+
+**`native`**
+
+```python
+loadLib(string lib_name) return object lib
+mapLib(string lib_name, object obj) return object lib
+```
+
+Example:
+
+```python
+import('native')
+
+object clib = loadLib("c")
+
+clib.printf("This message comes from native print function: %s %d", "Hello, 23)
+```
+
+By loading the library 'c', Dpdl automatically selects the appropriate library, on Linux/Unix/MAC 'libc' and on Windows 'msvcrt'.
 
 On Windows systems it's possible also to access the system library 'kernel32' and it provides COM support.
 
+
 Example Dpdl code accessing the system library 'libc' functions:
 ```python
 import('native')