diff --git a/jerry-core/ecma/base/ecma-helpers-char.cpp b/jerry-core/ecma/base/ecma-helpers-char.cpp
index f1f2c1fec..1f0196efa 100644
--- a/jerry-core/ecma/base/ecma-helpers-char.cpp
+++ b/jerry-core/ecma/base/ecma-helpers-char.cpp
@@ -62,6 +62,64 @@ ecma_char_is_line_terminator (ecma_char_t c) /**< character value */
           || ecma_char_is_new_line (c));
 } /* ecma_char_is_line_terminator */
 
+/**
+ * Check if specified character is a word character (part of IsWordChar abstract operation)
+ *
+ * See also: ECMA-262 v5, 15.10.2.6 (IsWordChar)
+ *
+ * @return true - if the character is a word character
+ *         false - otherwise.
+ */
+bool
+ecma_char_is_word_char (ecma_char_t c) /**< character value */
+{
+  if ((c >= 'a' && c <= 'z')
+      || (c >= 'A' && c <= 'Z')
+      || (c >= '0' && c <= '9')
+      || c == '_')
+  {
+    return true;
+  }
+
+  return false;
+} /* ecma_char_is_word_char */
+
+/**
+ * Convert a hex character to an unsigned integer
+ *
+ * @return digit value, corresponding to the hex char
+ */
+uint32_t
+ecma_char_hex_to_int (ecma_char_t hex) /**< [0-9A-Fa-f] character value */
+{
+  switch (hex)
+  {
+    case '0': return 0x0;
+    case '1': return 0x1;
+    case '2': return 0x2;
+    case '3': return 0x3;
+    case '4': return 0x4;
+    case '5': return 0x5;
+    case '6': return 0x6;
+    case '7': return 0x7;
+    case '8': return 0x8;
+    case '9': return 0x9;
+    case 'a':
+    case 'A': return 0xA;
+    case 'b':
+    case 'B': return 0xB;
+    case 'c':
+    case 'C': return 0xC;
+    case 'd':
+    case 'D': return 0xD;
+    case 'e':
+    case 'E': return 0xE;
+    case 'f':
+    case 'F': return 0xF;
+    default: JERRY_UNREACHABLE ();
+  }
+} /* ecma_char_hex_to_int */
+
 /**
  * @}
  * @}
diff --git a/jerry-core/ecma/base/ecma-helpers.h b/jerry-core/ecma/base/ecma-helpers.h
index 06c08f1d3..df4c4384d 100644
--- a/jerry-core/ecma/base/ecma-helpers.h
+++ b/jerry-core/ecma/base/ecma-helpers.h
@@ -334,6 +334,8 @@ extern ecma_length_t ecma_number_to_zt_string (ecma_number_t num, ecma_char_t *b
 extern bool ecma_char_is_new_line (ecma_char_t c);
 extern bool ecma_char_is_carriage_return (ecma_char_t c);
 extern bool ecma_char_is_line_terminator (ecma_char_t c);
+extern bool ecma_char_is_word_char (ecma_char_t c);
+extern uint32_t ecma_char_hex_to_int (ecma_char_t hex);
 
 #endif /* !JERRY_ECMA_HELPERS_H */
 
diff --git a/jerry-core/parser/js/lexer.cpp b/jerry-core/parser/js/lexer.cpp
index a5d375bdd..a3926cc55 100644
--- a/jerry-core/parser/js/lexer.cpp
+++ b/jerry-core/parser/js/lexer.cpp
@@ -1,4 +1,5 @@
 /* Copyright 2014-2015 Samsung Electronics Co., Ltd.
+ * Copyright 2015 University of Szeged.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -341,37 +342,6 @@ consume_char (void)
   } \
   while (0)
 
-static uint32_t
-hex_to_int (char hex)
-{
-  switch (hex)
-  {
-    case '0': return 0x0;
-    case '1': return 0x1;
-    case '2': return 0x2;
-    case '3': return 0x3;
-    case '4': return 0x4;
-    case '5': return 0x5;
-    case '6': return 0x6;
-    case '7': return 0x7;
-    case '8': return 0x8;
-    case '9': return 0x9;
-    case 'a':
-    case 'A': return 0xA;
-    case 'b':
-    case 'B': return 0xB;
-    case 'c':
-    case 'C': return 0xC;
-    case 'd':
-    case 'D': return 0xD;
-    case 'e':
-    case 'E': return 0xE;
-    case 'f':
-    case 'F': return 0xF;
-    default: JERRY_UNREACHABLE ();
-  }
-}
-
 /**
  * Try to decode specified character as SingleEscapeCharacter (ECMA-262, v5, 7.8.4)
  *
@@ -545,7 +515,7 @@ convert_string_to_token_transform_escape_seq (token_type tok_type, /**< type of
             JERRY_ASSERT ((char_code & 0xF000u) == 0);
 
             char_code = (uint16_t) (char_code << 4u);
-            char_code = (uint16_t) (char_code + hex_to_int (nc));
+            char_code = (uint16_t) (char_code + ecma_char_hex_to_int ((ecma_char_t) nc));
           }
         }
 
@@ -761,11 +731,11 @@ parse_number (void)
     {
       if (!is_overflow)
       {
-        res = (res << 4) + hex_to_int (token_start[i]);
+        res = (res << 4) + ecma_char_hex_to_int ((ecma_char_t) token_start[i]);
       }
       else
       {
-        fp_res = fp_res * 16 + (ecma_number_t) hex_to_int (token_start[i]);
+        fp_res = fp_res * 16 + (ecma_number_t) ecma_char_hex_to_int ((ecma_char_t) token_start[i]);
       }
 
       if (res > 255)
@@ -879,11 +849,11 @@ parse_number (void)
     {
       if (!is_overflow)
       {
-        res = res * 8 + hex_to_int (token_start[i]);
+        res = res * 8 + ecma_char_hex_to_int ((ecma_char_t) token_start[i]);
       }
       else
       {
-        fp_res = fp_res * 8 + (ecma_number_t) hex_to_int (token_start[i]);
+        fp_res = fp_res * 8 + (ecma_number_t) ecma_char_hex_to_int ((ecma_char_t) token_start[i]);
       }
       if (res > 255)
       {
@@ -899,11 +869,11 @@ parse_number (void)
     {
       if (!is_overflow)
       {
-        res = res * 10 + hex_to_int (token_start[i]);
+        res = res * 10 + ecma_char_hex_to_int ((ecma_char_t) token_start[i]);
       }
       else
       {
-        fp_res = fp_res * 10 + (ecma_number_t) hex_to_int (token_start[i]);
+        fp_res = fp_res * 10 + (ecma_number_t) ecma_char_hex_to_int ((ecma_char_t) token_start[i]);
       }
       if (res > 255)
       {