readme: add information section

[nit.git] / lib / c.nit

diff --git a/lib/c.nit b/lib/c.nit
index a4a8e01..076ea65 100644 (file)
--- a/lib/c.nit
+++ b/lib/c.nit
@@ -14,8 +14,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Utilities and performant structure for the FFI with C
+# Structures and services for compatibility with the C language
 module c
+
 import core
 intrude import core::collection::array
 
@@ -92,8 +93,8 @@ class CIntArray
                super size
        end
 
-       # Build from an `Array[Int]`
-       new from(array: Array[Int])
+       # Create from a `SequenceRead[Int]`
+       new from(array: SequenceRead[Int])
        do
                var carray = new CIntArray(array.length)
                for i in array.length.times do
@@ -117,6 +118,42 @@ extern class NativeCIntArray `{ int* `}
        redef fun +(offset) `{ return self + offset; `}
 end
 
+# Wrapper of a C array of type `uint16_t*` with length and destroy state
+class CUInt16Array
+       super CArray[Int]
+       redef type NATIVE: NativeCUInt16Array
+
+       # Initialize a new CIntArray of `size` elements.
+       init(size: Int) is old_style_init do
+               native_array = new NativeCUInt16Array(size)
+               super size
+       end
+
+       # Create from a `SequenceRead[Int]`
+       new from(array: SequenceRead[Int])
+       do
+               var carray = new CUInt16Array(array.length)
+               for i in array.length.times do
+                       carray[i] = array[i]
+               end
+               return carray
+       end
+end
+
+# An array of `uint16_t` in C
+extern class NativeCUInt16Array `{ uint16_t* `}
+       super NativeCArray
+       redef type E: Int
+
+       # Initialize a new NativeCUInt16Array of `size` elements.
+       new(size: Int) `{ return calloc(size, sizeof(uint16_t)); `}
+
+       redef fun [](index) `{ return self[index]; `}
+       redef fun []=(index, val) `{ self[index] = val; `}
+
+       redef fun +(offset) `{ return self + offset; `}
+end
+
 # Wrapper around an array of `unsigned char` in C (`unsigned char*`) with length and destroy state
 class CByteArray
        super CArray[Byte]
@@ -128,7 +165,7 @@ class CByteArray
                super size
        end
 
-       # Build from a `SequenceRead[Byte]`
+       # Create from a `SequenceRead[Byte]`
        new from(array: SequenceRead[Byte])
        do
                var carray = new CByteArray(array.length)
@@ -137,6 +174,18 @@ class CByteArray
                end
                return carray
        end
+
+       # Safely move `n` bytes from `dst_offset` to `src_offset`, inside this array
+       #
+       # Require: all arguments greater than 0 and ranges within `length`
+       fun move(dst_offset, src_offset, n: Int)
+       do
+               assert dst_offset >= 0 and src_offset >= 0 and n >= 0
+               assert dst_offset + n <= length
+               assert src_offset + n <= length
+
+               native_array.move(dst_offset, src_offset, n)
+       end
 end
 
 # An array of `unsigned char` in C (`unsigned char*`)
@@ -151,6 +200,11 @@ extern class NativeCByteArray `{ unsigned char* `}
        redef fun []=(index, val) `{ self[index] = val; `}
 
        redef fun +(offset) `{ return self + offset; `}
+
+       # Move `n` bytes from `dst_offset` to `src_offset`
+       fun move(dst_offset, src_offset, n: Int) `{
+               memmove(self+dst_offset, self+src_offset, n);
+       `}
 end
 
 # Wrapper around an array of `NativeString` in C (`char**`) with length and destroy state.
@@ -165,8 +219,8 @@ class CNativeStringArray
                super size
        end
 
-       # Build from an `Array[NativeString]`
-       new from(array: Array[NativeString])
+       # Create from an `SequenceRead[NativeString]`
+       new from(array: SequenceRead[NativeString])
        do
                var carray = new CNativeStringArray(array.length)
                for i in array.length.times do