Use binary search to check for string enumerations

1 files changed, 41 insertions, 0 deletions

diff --git a/libxsde/xsde/cxx/string-search.cxx b/libxsde/xsde/cxx/string-search.cxx
new file mode 100644
index 0000000..10da5f0
--- /dev/null
+++ b/libxsde/xsde/cxx/string-search.cxx
@@ -0,0 +1,41 @@
+// file      : xsde/cxx/string-search.cxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2005-2010 Code Synthesis Tools CC
+// license   : GNU GPL v2 + exceptions; see accompanying LICENSE file
+
+#include <string.h> // strcmp
+#include <xsde/cxx/string-search.hxx>
+
+namespace xsde
+{
+  namespace cxx
+  {
+    size_t
+    search (const char* const* array, size_t size, const char* s)
+    {
+      if (size == 0)
+        return 0;
+
+      int r (1);
+      size_t m;
+      size_t l = 0;
+      size_t h = size - 1;
+
+      while (l <= h)
+      {
+        m = l + (h - l) / 2;
+        r = strcmp (array[m], s);
+
+        if (r == 0)
+          break;
+
+        if (r < 0)
+          l = m + 1;
+        else
+          h = m - 1;
+      }
+
+      return r == 0 ? m : size;
+    }
+  }
+}