diff --git a/docs/TODO.txt b/docs/TODO.txt
index c78facf..5163c4a 100644
--- a/docs/TODO.txt
+++ b/docs/TODO.txt
@@ -38,14 +38,14 @@ DONE: better sugar for _push, _pop, _length
 DONE: nested compound assignment bug
 
 
-TODO: ternary operator?
-TODO: Nullish types?
 TODO: hooks on the external libraries, triggered on import
 TODO: standard library
 TODO: external script runner library
-TODO: document how it all works - book?
-TODO: better API?
+TODO: document how it all works
 TODO: packaging for release?
+TODO: test embedding
 
 NOPE: a = b = c = 1;
 NOPE: functions return a set number of values
+NOPE: ternary operator?
+NOPE: Nullish types?
diff --git a/source/lib_builtin.c b/source/lib_builtin.c
index 2a95271..6ae2d47 100644
--- a/source/lib_builtin.c
+++ b/source/lib_builtin.c
@@ -749,14 +749,15 @@ int _index(Interpreter* interpreter, LiteralArray* arguments) {
 
 			int lower = AS_INTEGER(third) > 0 ? AS_INTEGER(first) : AS_INTEGER(first) -1;
 			int min = AS_INTEGER(third) > 0 ? AS_INTEGER(first) : AS_INTEGER(second) -1;
+			int max = AS_INTEGER(third) > 0 ? AS_INTEGER(second) + (AS_INTEGER(second) == compoundLength ? -1 : 0) : AS_INTEGER(second);
 
 			//copy compound into result
 			int resultIndex = 0;
-			for (int i = min; i >= 0 && i >= lower && i <= AS_INTEGER(second); i += AS_INTEGER(third)) {
+			for (int i = min; i >= 0 && i >= lower && i <= max; i += AS_INTEGER(third)) {
 				result[ resultIndex++ ] = AS_STRING(compound)[ i ];
 			}
 
-			result[ resultIndex++ ] = '\0';
+			result[ resultIndex ] = '\0';
 
 			//finally, swap out the compound for the result
 			freeLiteral(compound);
@@ -884,7 +885,7 @@ int _index(Interpreter* interpreter, LiteralArray* arguments) {
 					result[ resultIndex++ ] = AS_STRING(compound)[ i ];
 				}
 
-				result[ resultIndex++ ] = '\0';
+				result[ resultIndex ] = '\0';
 			}
 
 			//else override elements of the array instead
diff --git a/source/literal.c b/source/literal.c
index 76ffa5c..f62ebe3 100644
--- a/source/literal.c
+++ b/source/literal.c
@@ -112,7 +112,7 @@ Literal copyLiteral(Literal original) {
 			return original;
 
 		case LITERAL_STRING: {
-			return TO_STRING_LITERAL(copyString(AS_STRING(original), strlen(AS_STRING(original))), strlen(AS_STRING(original)));
+			return TO_STRING_LITERAL(copyString(AS_STRING(original), original.as.string.length), original.as.string.length);
 		}
 
 		case LITERAL_ARRAY: {
@@ -152,7 +152,7 @@ Literal copyLiteral(Literal original) {
 		}
 
 		case LITERAL_IDENTIFIER: {
-			 return TO_IDENTIFIER_LITERAL(copyString(AS_IDENTIFIER(original), strlen(AS_IDENTIFIER(original)) ), strlen(AS_IDENTIFIER(original)));
+			 return TO_IDENTIFIER_LITERAL(copyString(AS_IDENTIFIER(original), original.as.identifier.length), original.as.identifier.length);
 		}
 
 		case LITERAL_TYPE: {
@@ -246,10 +246,10 @@ bool literalsAreEqual(Literal lhs, Literal rhs) {
 			return AS_FLOAT(lhs) == AS_FLOAT(rhs);
 
 		case LITERAL_STRING:
-			if (strlen(AS_STRING(lhs)) != strlen(AS_STRING(rhs))) {
+			if (lhs.as.string.length != rhs.as.string.length) {
 				return false;
 			}
-			return !strncmp(AS_STRING(lhs), AS_STRING(rhs), strlen(AS_STRING(lhs)));
+			return !strncmp(AS_STRING(lhs), AS_STRING(rhs), lhs.as.string.length);
 
 		case LITERAL_ARRAY:
 		case LITERAL_DICTIONARY_INTERMEDIATE: //BUGFIX
@@ -295,11 +295,11 @@ bool literalsAreEqual(Literal lhs, Literal rhs) {
 
 		case LITERAL_IDENTIFIER:
 			//check shortcuts
-			if (HASH_I(lhs) != HASH_I(rhs) && strlen(AS_IDENTIFIER(lhs)) != strlen(AS_IDENTIFIER(rhs))) {
+			if (HASH_I(lhs) != HASH_I(rhs) && lhs.as.identifier.length != rhs.as.identifier.length) {
 				return false;
 			}
 
-			return !strncmp(AS_IDENTIFIER(lhs), AS_IDENTIFIER(rhs), strlen( AS_IDENTIFIER(lhs) ));
+			return !strncmp(AS_IDENTIFIER(lhs), AS_IDENTIFIER(rhs), lhs.as.identifier.length);
 
 		case LITERAL_TYPE:
 			//check types
diff --git a/source/literal.h b/source/literal.h
index e3159d5..e49cdb9 100644
--- a/source/literal.h
+++ b/source/literal.h
@@ -13,16 +13,16 @@ typedef enum {
 	LITERAL_ARRAY,
 	LITERAL_DICTIONARY,
 	LITERAL_FUNCTION,
-
-	//these are meta-level types
 	LITERAL_IDENTIFIER,
 	LITERAL_TYPE,
+	LITERAL_ANY,
+
+	//these are meta-level types - not for general use
 	LITERAL_TYPE_INTERMEDIATE, //used to process types in the compiler only
 	LITERAL_DICTIONARY_INTERMEDIATE, //used to process dictionaries in the compiler only
 	LITERAL_FUNCTION_INTERMEDIATE, //used to process functions in the compiler only
-	LITERAL_FUNCTION_ARG_REST, //used to process function rest parameters
-	LITERAL_FUNCTION_NATIVE, //for handling native functions
-	LITERAL_ANY, //used by the type system only
+	LITERAL_FUNCTION_ARG_REST, //used to process function rest parameters only
+	LITERAL_FUNCTION_NATIVE, //for handling native functions only
 } LiteralType;
 
 typedef struct {