[[feature-random]] MLC: Add "random bytes" expression.

peter-b · peter-b · commit 110795a9d051 · 2015-01-16T13:14:43.000Z
Add a new expression for random data generation, e.g.

    put 436 random bytes into tData
diff --git a/libscript/src/byte.mlc b/libscript/src/byte.mlc
@@ -52,6 +52,8 @@ public foreign handler MCByteExecDeleteByteRangeOf(in Start as index, in Finish
 public foreign handler MCByteExecDeleteLastByteOf(inout Target as data) as undefined binds to "<builtin>"
 public foreign handler MCByteExecDeleteFirstByteOf(inout Target as data) as undefined binds to "<builtin>"
 
+public foreign handler MCDataExecRandomBytes(in Count as uindex, out Value as data) as undefined binds to "<builtin>"
+
 --
 
 /*
@@ -406,4 +408,23 @@ end syntax
 
 --
 
+/*
+Summary:	Generate random data
+Count:		Expression evaluating to the number of bytes to generate
+
+Description:
+Generates the requested number of bytes of cryptographic-quality
+random data.
+
+Tags: Binary, Random
+
+*/
+syntax RandomBytes is postfix operator with precedence 5
+	<Count : Expression> "random" "bytes"
+begin
+	MCDataExecRandomBytes(Count, output)
+end syntax
+
+--
+
 end module
diff --git a/libscript/src/module-byte.cpp b/libscript/src/module-byte.cpp
@@ -204,6 +204,14 @@ extern "C" MC_DLLEXPORT bool MCByteRepeatForEachByte(void*& x_iterator, MCDataRe
     return true;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+
+extern "C" MC_DLLEXPORT void
+MCDataExecRandomBytes (uindex_t p_count, MCDataRef & r_data)
+{
+	/* UNCHECKED */ MCDataCreateRandom (p_count, r_data);
+}
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
 #ifdef _TEST
