1 files changed, 20 insertions, 0 deletions
diff --git a/src/piraha/Boundary.cc b/src/piraha/Boundary.cc
new file mode 100644
index 00000000..6c34335b
--- /dev/null
+++ b/src/piraha/Boundary.cc
@@ -0,0 +1,20 @@
+#include "Piraha.hpp"
+
+using namespace piraha;
+
+bool is_c_ident(char c) {
+    return ('a' <= c && c <= 'z')
+        || ('A' <= c && c <= 'Z')
+        || ('0' <= c && c <= '9')
+        || c == '_';
+}
+
+bool Boundary::match(Matcher *m) {
+    if(m->pos == 0 || m->pos == (int)m->input_size)
+        return true;
+    char c2 =  m->input[m->pos];
+    char c1 =  m->input[m->pos-1];
+    bool b1 = is_c_ident(c1);
+    bool b2 = is_c_ident(c2);
+    return !b1 || !b2;
+}