diff --git a/builtins.simple b/builtins.simple
index 95d3387..1276b19 100644
--- a/builtins.simple
+++ b/builtins.simple
@@ -69,6 +69,8 @@ object strtrait:
 
     def add(other):
         self $str_add(other)
+    def substr(s, e):
+        self $str_subs(s, e)
     def rev:
         self $str_rev
     def len:
diff --git a/de.churl.simple/objmodel.py b/de.churl.simple/objmodel.py
index c2ed1bd..373d71d 100644
--- a/de.churl.simple/objmodel.py
+++ b/de.churl.simple/objmodel.py
@@ -104,7 +104,7 @@ class PrimitiveObject(AbstractObject):
 
 class W_Integer(PrimitiveObject):
     def __init__(self, value, space=None):
-        super().__init__(int(value), "inttrait", space)
+        super().__init__(int(value), "inttrait", space=space)
 
 
 class W_Boolean(PrimitiveObject):
@@ -119,12 +119,12 @@ class W_Boolean(PrimitiveObject):
 
 class W_String(PrimitiveObject):
     def __init__(self, value, space=None):
-        super().__init__(str(value), "strtrait", space)
+        super().__init__(str(value), "strtrait", space=space)
 
 
 class W_Double(PrimitiveObject):
     def __init__(self, value, space=None):
-        super().__init__(float(value), "doubletrait", space)
+        super().__init__(float(value), "doubletrait", space=space)
 
 
 # -------------
diff --git a/de.churl.simple/primitives.py b/de.churl.simple/primitives.py
index 3bac0da..c4a0806 100644
--- a/de.churl.simple/primitives.py
+++ b/de.churl.simple/primitives.py
@@ -173,6 +173,11 @@ def simple_str_add(a, b):
     return a + b
 
 
+@primitive("str_subs", [str, int, int], str)
+def simple_str_subs(a, s, e):
+    return a[s:e]
+
+
 @primitive("str_rev", [str], str)
 def simple_str_eq(a):
     return a[::-1]
diff --git a/de.churl.simple/simplelexer.py b/de.churl.simple/simplelexer.py
index 4620e99..69e7b4e 100644
--- a/de.churl.simple/simplelexer.py
+++ b/de.churl.simple/simplelexer.py
@@ -173,10 +173,10 @@ Plus = r'\+'
 Minus = r'-'
 Multiply = r'\*'
 Divide = r'/'
-Increment = r'\+\+'
-Decrement = r'--'
 Modulo = r'%'
 
+Increment = r'\+\+'
+Decrement = r'--'
 PlusInplace = r'\+='
 MinusInplace = r'-='
 MultiplyInplace = r'\*='
@@ -206,15 +206,14 @@ Object = r'object'
 
 tokens = ["If", "Else", "While", "Def", "Object", "Ignore",
           "String", "Boolean", "Double",
-          "Number",  # after Double
+          "Number",
           "GC",
           "NewlineAndWhitespace", "OpenBracket", "CloseBracket", "Comma", "Colon",
           "And", "Or", "LessEqual", "Less", "GreaterEqual", "Greater", "Equal", "NotEqual",
           "Decrement", "PlusInplace", "MinusInplace", "MultiplyInplace", "DivideInplace",
           "Increment", "Plus", "Minus", "Multiply", "Divide", "Modulo",
           "Assign", "Not",
-          "Name", "PrimitiveName",
-          ]
+          "Name", "PrimitiveName"]
 
 
 def make_lexer():