diff --git a/stdlib/lexer.krak b/stdlib/lexer.krak
index d966a0d..626ed15 100644
--- a/stdlib/lexer.krak
+++ b/stdlib/lexer.krak
@@ -63,6 +63,7 @@ obj lexer (Object) {
     fun next(): symbol::symbol {
         if (position >= input.length())
             return symbol::eof_symbol()
+        /*
         var max = regs.map(fun(reg_pair: util::pair<string::string,regex::regex>): util::pair<int, string::string> {
                 return util::make_pair(reg_pair.second.long_match(input.slice(position, -1)), reg_pair.first); })
                 .max(fun(first: util::pair<int, string::string>, second: util::pair<int, string::string>): bool
@@ -71,6 +72,20 @@ obj lexer (Object) {
             return symbol::invalid_symbol()
         position += max.first
         return symbol::symbol(max.second, true, input.slice(position-max.first, position))
+        */
+        var max = -1
+        var max_length = -1
+        for (var i = 0; i < regs.size; i++;) {
+            var new_length = regs[i].second.long_match(input.getBackingMemory(), position, input.length())
+            if (new_length > max_length) {
+                max = i
+                max_length = new_length
+            }
+        }
+        if (max < 0)
+            return symbol::invalid_symbol()
+        position += max_length
+        return symbol::symbol(regs[max].first, true, input.slice(position-max_length, position))
     }
 }
 
diff --git a/stdlib/regex.krak b/stdlib/regex.krak
index abefee1..afc8f41 100644
--- a/stdlib/regex.krak
+++ b/stdlib/regex.krak
@@ -180,19 +180,20 @@ obj regex (Object, Serializable) {
     }
 
     fun long_match(to_match: *char): int { return long_match(string::string(to_match)); }
-    fun long_match(to_match: string::string): int {
+    fun long_match(to_match: string::string): int return long_match(to_match.getBackingMemory(), 0, to_match.length())
+    fun long_match(to_match: *char, position: int, end: int): int {
         var next = set::set(begin)
         var longest = -1
-        for (var i = 0; i < to_match.length(); i++;) {
+        for (var i = 0; i < end-position; i++;) {
             if (next.size() == 0)
                 return longest
             if (next.any_true(fun(state: *regexState):bool { return state->is_end(); }))
                 longest = i
             //next = next.flatten_map<*regexState>(fun(state: *regexState): vector::vector<*regexState> { return state->match_char(to_match[i]); })
-            next = next.flatten_map(fun(state: *regexState): set::set<*regexState> { return state->match_char(to_match[i]); })
+            next = next.flatten_map(fun(state: *regexState): set::set<*regexState> { return state->match_char(to_match[position+i]); })
         }
         if (next.any_true(fun(state: *regexState):bool { return state->is_end(); }))
-            return to_match.length()
+            return end-position
         return longest
     }
 }
diff --git a/stdlib/string.krak b/stdlib/string.krak
index 29344ac..b9ae803 100644
--- a/stdlib/string.krak
+++ b/stdlib/string.krak
@@ -148,6 +148,7 @@ obj string (Object, Serializable) {
         out[data.size] = 0
         return out;
     }
+    fun getBackingMemory(): *char return data.getBackingMemory();
 
     fun split(delim: *char): vector::vector<string> return split(string(delim))
     fun split(delim: string): vector::vector<string> {
diff --git a/stdlib/vector.krak b/stdlib/vector.krak
index e5ea470..f9ccc9c 100644
--- a/stdlib/vector.krak
+++ b/stdlib/vector.krak
@@ -121,11 +121,11 @@ obj vector<T> (Object, Serializable) {
     }
 
     fun slice(start: int, end: int): vector<T> {
-        var new.construct(): vector<T>
         if (start < 0)
             start += size + 1
         if (end < 0)
             end += size + 1
+        var new.construct(end-start): vector<T>
         for (var i = start; i < end; i++;)
             new.add(data[i])
         return new
@@ -229,6 +229,12 @@ obj vector<T> (Object, Serializable) {
         for (var i = 0; i < size; i++;)
             data[i] = func(data[i])
     }
+    fun map<U>(func: fun(ref T):U):vector<U> {
+        var newVec.construct(size): vector<U>
+        for (var i = 0; i < size; i++;)
+            newVec.addEnd(func(data[i]))
+        return newVec
+    }
     fun map<U>(func: fun(T):U):vector<U> {
         var newVec.construct(size): vector<U>
         for (var i = 0; i < size; i++;)
@@ -257,6 +263,13 @@ obj vector<T> (Object, Serializable) {
                 return true
         return false
     }
+    fun max(func: fun(ref T, ref T):bool): T {
+        var maxIdx = 0
+        for (var i = 1; i < size; i++;)
+            if (func(data[maxIdx], data[i]))
+                maxIdx = i
+        return data[maxIdx]
+    }
     fun max(func: fun(T,T):bool): T {
         var maxIdx = 0
         for (var i = 1; i < size; i++;)