tree_schema_helpers ADD function to match YANG keyword
diff --git a/src/tree_schema_helpers.c b/src/tree_schema_helpers.c
index 0d0620c..960b461 100644
--- a/src/tree_schema_helpers.c
+++ b/src/tree_schema_helpers.c
@@ -126,3 +126,197 @@
 
     return NULL;
 }
+
+#define MOVE_INPUT(DATA, COUNT) (data)+=COUNT;
+#define IF_KW(STR, LEN, STMT) if (!strncmp((data), STR, LEN)) {MOVE_INPUT(data, LEN);kw=STMT;}
+#define IF_KW_PREFIX(STR, LEN) if (!strncmp((data), STR, LEN)) {MOVE_INPUT(data, LEN);
+#define IF_KW_PREFIX_END }
+
+enum yang_keyword
+match_keyword(char *data)
+{
+    enum yang_keyword kw = YANG_NONE;
+    /* read the keyword itself */
+    switch (*data) {
+    case 'a':
+        MOVE_INPUT(data, 1);
+        IF_KW("rgument", 7, YANG_ARGUMENT)
+        else IF_KW("ugment", 6, YANG_AUGMENT)
+        else IF_KW("ction", 5, YANG_ACTION)
+        else IF_KW_PREFIX("ny", 2)
+            IF_KW("data", 4, YANG_ANYDATA)
+            else IF_KW("xml", 3, YANG_ANYXML)
+        IF_KW_PREFIX_END
+        break;
+    case 'b':
+        MOVE_INPUT(data, 1);
+        IF_KW("ase", 3, YANG_BASE)
+        else IF_KW("elongs-to", 9, YANG_BELONGS_TO)
+        else IF_KW("it", 2, YANG_BIT)
+        break;
+    case 'c':
+        MOVE_INPUT(data, 1);
+        IF_KW("ase", 3, YANG_CASE)
+        else IF_KW("hoice", 5, YANG_CHOICE)
+        else IF_KW_PREFIX("on", 2)
+            IF_KW("fig", 3, YANG_CONFIG)
+            else IF_KW_PREFIX("ta", 2)
+                IF_KW("ct", 2, YANG_CONTACT)
+                else IF_KW("iner", 4, YANG_CONTAINER)
+            IF_KW_PREFIX_END
+        IF_KW_PREFIX_END
+        break;
+    case 'd':
+        MOVE_INPUT(data, 1);
+        IF_KW_PREFIX("e", 1)
+            IF_KW("fault", 5, YANG_DEFAULT)
+            else IF_KW("scription", 9, YANG_DESCRIPTION)
+            else IF_KW_PREFIX("viat", 4)
+                IF_KW("e", 1, YANG_DEVIATE)
+                else IF_KW("ion", 3, YANG_DEVIATION)
+            IF_KW_PREFIX_END
+        IF_KW_PREFIX_END
+        break;
+    case 'e':
+        MOVE_INPUT(data, 1);
+        IF_KW("num", 3, YANG_ENUM)
+        else IF_KW_PREFIX("rror-", 5)
+            IF_KW("app-tag", 7, YANG_ERROR_APP_TAG)
+            else IF_KW("message", 7, YANG_ERROR_MESSAGE)
+        IF_KW_PREFIX_END
+        else IF_KW("xtension", 8, YANG_EXTENSION)
+        break;
+    case 'f':
+        MOVE_INPUT(data, 1);
+        IF_KW("eature", 6, YANG_FEATURE)
+        else IF_KW("raction-digits", 14, YANG_FRACTION_DIGITS)
+        break;
+    case 'g':
+        MOVE_INPUT(data, 1);
+        IF_KW("rouping", 7, YANG_GROUPING)
+        break;
+    case 'i':
+        MOVE_INPUT(data, 1);
+        IF_KW("dentity", 7, YANG_IDENTITY)
+        else IF_KW("f-feature", 9, YANG_IF_FEATURE)
+        else IF_KW("mport", 5, YANG_IMPORT)
+        else IF_KW_PREFIX("n", 1)
+            IF_KW("clude", 5, YANG_INCLUDE)
+            else IF_KW("put", 3, YANG_INPUT)
+        IF_KW_PREFIX_END
+        break;
+    case 'k':
+        MOVE_INPUT(data, 1);
+        IF_KW("ey", 2, YANG_KEY)
+        break;
+    case 'l':
+        MOVE_INPUT(data, 1);
+        IF_KW_PREFIX("e", 1)
+            IF_KW("af-list", 7, YANG_LEAF_LIST)
+            else IF_KW("af", 2, YANG_LEAF)
+            else IF_KW("ngth", 4, YANG_LENGTH)
+        IF_KW_PREFIX_END
+        else IF_KW("ist", 3, YANG_LIST)
+        break;
+    case 'm':
+        MOVE_INPUT(data, 1);
+        IF_KW_PREFIX("a", 1)
+            IF_KW("ndatory", 7, YANG_MANDATORY)
+            else IF_KW("x-elements", 10, YANG_MAX_ELEMENTS)
+        IF_KW_PREFIX_END
+        else IF_KW("in-elements", 11, YANG_MIN_ELEMENTS)
+        else IF_KW("ust", 3, YANG_MUST)
+        else IF_KW_PREFIX("od", 2)
+            IF_KW("ule", 3, YANG_MODULE)
+            else IF_KW("ifier", 5, YANG_MODIFIER)
+        IF_KW_PREFIX_END
+        break;
+    case 'n':
+        MOVE_INPUT(data, 1);
+        IF_KW("amespace", 8, YANG_NAMESPACE)
+        else IF_KW("otification", 11, YANG_NOTIFICATION)
+        break;
+    case 'o':
+        MOVE_INPUT(data, 1);
+        IF_KW_PREFIX("r", 1)
+            IF_KW("dered-by", 8, YANG_ORDERED_BY)
+            else IF_KW("ganization", 10, YANG_ORGANIZATION)
+        IF_KW_PREFIX_END
+        else IF_KW("utput", 5, YANG_OUTPUT)
+        break;
+    case 'p':
+        MOVE_INPUT(data, 1);
+        IF_KW("ath", 3, YANG_PATH)
+        else IF_KW("attern", 6, YANG_PATTERN)
+        else IF_KW("osition", 7, YANG_POSITION)
+        else IF_KW_PREFIX("re", 2)
+            IF_KW("fix", 3, YANG_PREFIX)
+            else IF_KW("sence", 5, YANG_PRESENCE)
+        IF_KW_PREFIX_END
+        break;
+    case 'r':
+        MOVE_INPUT(data, 1);
+        IF_KW("ange", 4, YANG_RANGE)
+        else IF_KW_PREFIX("e", 1)
+            IF_KW_PREFIX("f", 1)
+                IF_KW("erence", 6, YANG_REFERENCE)
+                else IF_KW("ine", 3, YANG_REFINE)
+            IF_KW_PREFIX_END
+            else IF_KW("quire-instance", 14, YANG_REQUIRE_INSTANCE)
+            else IF_KW("vision-date", 11, YANG_REVISION_DATE)
+            else IF_KW("vision", 6, YANG_REVISION)
+        IF_KW_PREFIX_END
+        else IF_KW("pc", 2, YANG_RPC)
+        break;
+    case 's':
+        MOVE_INPUT(data, 1);
+        IF_KW("tatus", 5, YANG_STATUS)
+        else IF_KW("ubmodule", 8, YANG_SUBMODULE)
+        break;
+    case 't':
+        MOVE_INPUT(data, 1);
+        IF_KW("ypedef", 6, YANG_TYPEDEF)
+        else IF_KW("ype", 3, YANG_TYPE)
+        break;
+    case 'u':
+        MOVE_INPUT(data, 1);
+        IF_KW_PREFIX("ni", 2)
+            IF_KW("que", 3, YANG_UNIQUE)
+            else IF_KW("ts", 2, YANG_UNITS)
+        IF_KW_PREFIX_END
+        else IF_KW("ses", 3, YANG_USES)
+        break;
+    case 'v':
+        MOVE_INPUT(data, 1);
+        IF_KW("alue", 4, YANG_VALUE)
+        break;
+    case 'w':
+        MOVE_INPUT(data, 1);
+        IF_KW("hen", 3, YANG_WHEN)
+        break;
+    case 'y':
+        MOVE_INPUT(data, 1);
+        IF_KW("ang-version", 11, YANG_YANG_VERSION)
+        else IF_KW("in-element", 10, YANG_YIN_ELEMENT)
+        break;
+    case ';':
+        MOVE_INPUT(data, 1);
+        kw = YANG_SEMICOLON;
+        //goto success;
+        break;
+    case '{':
+        MOVE_INPUT(data, 1);
+        kw = YANG_LEFT_BRACE;
+        //goto success;
+        break;
+    case '}':
+        MOVE_INPUT(data, 1);
+        kw = YANG_RIGHT_BRACE;
+        //goto success;
+        break;
+    default:
+        break;
+    }
+
+    return kw;
+}