diff --git a/smnp/Evaluator.py b/smnp/Evaluator.py
deleted file mode 100644
index f89c9f1..0000000
--- a/smnp/Evaluator.py
+++ /dev/null
@@ -1,204 +0,0 @@
-from AST import *
-from Note import Note
-from Error import RuntimeException
-
-def evaluateProgram(program, environment):
-    for node in program.children:
-        evaluate(node, environment)
-
-def evaluateInteger(integer, environment):    
-    return integer.value
-
-def evaluatePercent(percent, environment):
-    return percent.value.value * 0.01
-
-def evaluateIdentifier(identifier, environment):
-    value = environment.findVariable(identifier.identifier)
-    return value
-
-def evaluateString(string, environment):    
-    value = string.value    
-    for scope in reversed(environment.scopes):
-        for k, v in scope.items():
-            value = value.replace('{' + k + '}', objectString(v)) #TODO: poprawic
-    return value
-
-
-
-def evaluateNote(note, environment):
-    return note.value
-
-def evaluateFunctionDefinition(definition, environment):
-    name = definition.name
-    params = list([p for p in flatListNode(definition.parameters) if not isinstance(p, CommaNode)])
-    body = definition.body
-    
-    if not isinstance(definition.parent, Program):
-        raise RuntimeException(name.pos, f"Functions can be defined only on the top level of script")
-    
-    for p in params:
-        if not isinstance(p, IdentifierNode):
-            raise RuntimeException(p.pos, "Parameter of function definition must be an identifier")
-        
-    if name.identifier in environment.customFunctions or name.identifier in environment.functions:
-        raise RuntimeException(name.pos, f"Function '{name.identifier}' already exists")
-    
-    environment.customFunctions[name.identifier] = {
-        'params': params,
-        'body': flatListNode(body)
-    }
-    
-def flatListNode(listNode):
-    if len(listNode.children[0].children) == 1:
-        return []
-    return _flatListNode(listNode.children[0], [])
-
-def _flatListNode(listItemNode, list = []):        
-    if len(listItemNode.children) == 2:        
-        child1 = listItemNode.children[0]    
-        child2 = listItemNode.children[1]        
-        list.append(child1)
-        _flatListNode(child2, list)    
-    return list
-
-def evaluateAccess(access, environment):
-    
-    element = evaluate(access.element, environment)
-    #TODO: narazie tylko metody działają        
-    e = evaluateMethodCall(element, access.property, environment)
-    return e
-    
-def evaluateMethodCall(element, functionCall, environment):
-    funcName = functionCall.identifier.identifier
-    arguments = evaluateList(functionCall.arguments, environment)
-    arguments.insert(0, element)    
-    #for name, function in environment.customFunctions.items():
-        #if funcName == name:
-            #if len(function['params']) != len(arguments):
-                #raise RuntimeException(functionCall.pos, f"Calling '{funcName}' requires {len(function['params'])} and {len(arguments)} was passed")
-            #environment.scopes.append({ function['params'][i].identifier: v for i, v in enumerate(arguments) })                      
-            #returnValue = None            
-            #for node in function['body']:                   
-                #if not isinstance(node, ReturnNode):
-                    #evaluate(node, environment)     
-                #else:                    
-                    #returnValue = evaluateReturn(node, environment)
-            #environment.scopes.pop(-1)
-            #return returnValue    
-    for name, definition in environment.methods[type(element)].items():        
-        if name == funcName:            
-            return definition(arguments, environment)
-    raise RuntimeException(functionCall.pos, f"Method '{funcName}' does not exist")
-
-def evaluateFunctionCall(functionCall, environment):         
-    funcName = functionCall.identifier.identifier
-    arguments = evaluateList(functionCall.arguments, environment)       
-    for name, function in environment.customFunctions.items():
-        if funcName == name:
-            if len(function['params']) != len(arguments):
-                raise RuntimeException(functionCall.pos, f"Calling '{funcName}' requires {len(function['params'])} and {len(arguments)} was passed")
-            environment.scopes.append({ function['params'][i].identifier: v for i, v in enumerate(arguments) })                      
-            returnValue = None            
-            for node in function['body']:                   
-                if not isinstance(node, ReturnNode):
-                    evaluate(node, environment)     
-                else:                    
-                    returnValue = evaluateReturn(node, environment)
-            environment.scopes.pop(-1)
-            return returnValue
-    for name, definition in environment.functions.items():
-        if name == funcName:
-            return definition(arguments, environment)
-    raise RuntimeException(functionCall.pos, f"Function '{funcName}' does not exist")
-        
-def evaluateReturn(returnNode, environment):
-    return evaluate(returnNode.value, environment)
-
-def evaluateComma(comma, environment):
-    pass
-
-def evaluateBlock(block, environment):
-    environment.scopes.append({})
-    for node in flatListNode(block):
-        evaluate(node, environment)
-    environment.scopes.pop(-1)
-
-def evaluateList(list, environment):
-    return [evaluate(e, environment) for e in flatListNode(list) if not isinstance(e, CommaNode)]    
-
-def evaluateAssignment(assignment, environment):
-    target = assignment.target.identifier
-    value = evaluate(assignment.value, environment)
-    scopeOfExistingVariable = environment.findVariableScope(target)
-    if scopeOfExistingVariable is not None:
-        scopeOfExistingVariable[target] = value
-    else:
-        environment.scopes[-1][target] = value
-
-def evaluateAsterisk(asterisk, environment):    
-    count = evaluate(asterisk.iterator, environment)
-    if isinstance(count, int):
-        for i in range(count):
-            if isinstance(asterisk.iterator, IdentifierNode):
-                environment.scopes[-1][f"_{asterisk.iterator.identifier}"] = i+1
-            else:
-                environment.scopes[-1]["_"] = i+1
-            evaluate(asterisk.statement, environment)
-        if isinstance(asterisk.iterator, IdentifierNode):
-            del environment.scopes[-1][f"_{asterisk.iterator.identifier}"]
-        else: 
-            environment.scopes[-1]["_"] = i+1
-    elif isinstance(count, list):
-        for i, v in enumerate(count):
-            if isinstance(asterisk.iterator, IdentifierNode):
-                environment.scopes[-1][f"_{asterisk.iterator.identifier}"] = i+1
-                environment.scopes[-1][f"{asterisk.iterator.identifier}_"] = v
-            else:
-                environment.scopes[-1]["_"] = i+1
-                environment.scopes[-1]["__"] = v
-            evaluate(asterisk.statement, environment)
-            if isinstance(asterisk.iterator, IdentifierNode):
-                del environment.scopes[-1][f"_{asterisk.iterator.identifier}"]
-                del environment.scopes[-1][f"{asterisk.iterator.identifier}_"]
-            else:
-                del environment.scopes[-1]["_"]
-                del environment.scopes[-1]["__"]
-    
-def evaluateColon(colon, environment):     
-    if isinstance(colon.a, NoteLiteralNode) and isinstance(colon.b, NoteLiteralNode):
-        return Note.range(colon.a.value, colon.b.value)
-    elif isinstance(colon.a, IntegerLiteralNode) and isinstance(colon.b, IntegerLiteralNode):
-        return list(range(colon.a.value, colon.b.value+1))
-    raise RuntimeException(colon.pos, "Invalid colon arguments")
-
-def evaluate(input, environment):     
-    if isinstance(input, Program):
-        return evaluateProgram(input, environment)
-    if isinstance(input, IntegerLiteralNode):
-        return evaluateInteger(input, environment)
-    if isinstance(input, PercentNode):
-        return evaluatePercent(input, environment)
-    if isinstance(input, StringLiteralNode):
-        return evaluateString(input, environment)
-    if isinstance(input, NoteLiteralNode):
-        return evaluateNote(input, environment)
-    if isinstance(input, FunctionDefinitionNode):
-        return evaluateFunctionDefinition(input, environment)
-    if isinstance(input, FunctionCallNode):
-        return evaluateFunctionCall(input, environment)
-    if isinstance(input, AccessNode):
-        return evaluateAccess(input, environment)
-    if isinstance(input, CommaNode):    
-        return evaluateComma(input, environment)
-    if isinstance(input, BlockNode):
-        return evaluateBlock(input, environment)
-    if isinstance(input, ListNode):
-        return evaluateList(input, environment)
-    if isinstance(input, AssignmentNode):
-        return evaluateAssignment(input, environment)
-    if isinstance(input, AsteriskNode):
-        return evaluateAsterisk(input, environment)
-    if isinstance(input, ColonNode):
-        return evaluateColon(input, environment)
-    if isinstance(input, IdentifierNode):
-        return evaluateIdentifier(input, environment)
diff --git a/smnp/ast/parsers/block.py b/smnp/ast/parsers/block.py
index a6320b8..1abd442 100644
--- a/smnp/ast/parsers/block.py
+++ b/smnp/ast/parsers/block.py
@@ -1,4 +1,5 @@
 from smnp.ast.node.block import BlockNode, CloseBlockNode, BlockItemNode
+from smnp.ast.parsers.statement import parseStatement
 from smnp.token.type import TokenType
 
 
diff --git a/smnp/ast/parsers/colon.py b/smnp/ast/parsers/colon.py
index 9ee7333..b093154 100644
--- a/smnp/ast/parsers/colon.py
+++ b/smnp/ast/parsers/colon.py
@@ -1,4 +1,5 @@
 from smnp.ast.node.colon import ColonNode
+from smnp.ast.parsers.expression import parseExpression
 from smnp.error.syntax import SyntaxException
 from smnp.token.type import TokenType
 
@@ -11,7 +12,7 @@ def parseColon(expr1, input, parent):
         expr2 = parseExpression(input, parent)
 
         if expr2 is None:
-            raise SyntaxException(input.current().pos, f"Expected expression '{input.current().value}'")
+            raise SyntaxException(f"Expected expression '{input.current().value}'", input.current().pos)
         colon = ColonNode(expr1, expr2, parent, token.pos)
         expr1.parent = colon
         expr2.parent = colon
diff --git a/smnp/ast/parsers/token.py b/smnp/ast/parsers/token.py
index afaaad6..ac76411 100644
--- a/smnp/ast/parsers/token.py
+++ b/smnp/ast/parsers/token.py
@@ -7,6 +7,6 @@ def parseToken(input, parent):
     value = combineParsers([ parseStatement ])(input, parent)
 
     if value is None:
-        raise SyntaxException(None, "Unknown statement")  # TODO
+        raise SyntaxException("Unknown statement")  # TODO
 
     return value
\ No newline at end of file
diff --git a/smnp/ast/tools.py b/smnp/ast/tools.py
index 058afb5..4de9edd 100644
--- a/smnp/ast/tools.py
+++ b/smnp/ast/tools.py
@@ -15,9 +15,9 @@ def rollup(parser):
 
 def assertToken(expected, input):    
     if not input.hasCurrent():
-        raise SyntaxException(None, f"Expected '{expected}'")    
+        raise SyntaxException(f"Expected '{expected}'")
     if expected != input.current().type:
-        raise SyntaxException(input.current().pos, f"Expected '{expected}', found '{input.current().value}'")
+        raise SyntaxException(f"Expected '{expected}', found '{input.current().value}'", input.current().pos)
 
 
 def combineParsers(parsers):
diff --git a/smnp/environment/environment.py b/smnp/environment/environment.py
index aec354a..3878374 100644
--- a/smnp/environment/environment.py
+++ b/smnp/environment/environment.py
@@ -36,8 +36,8 @@ class Environment():
                         return value
                 else:
                     return value
-        raise RuntimeException(pos, f"Variable '{name}' is not declared" + (
-            "" if type is None else f" (expected type: {type})"))
+        raise RuntimeException(f"Variable '{name}' is not declared" + (
+            "" if type is None else f" (expected type: {type})"), pos)
 
     def findVariableScope(self, name, type=None):
         for scope in reversed(self.scopes):
@@ -46,4 +46,20 @@ class Environment():
                     if isinstance(scope[name], type):
                         return scope
                 else:
-                    return scope
\ No newline at end of file
+                    return scope
+
+    def scopesToString(self):
+        return "Scopes:\n" + ("\n".join([ f"  [{i}]: {scope}" for i, scope in enumerate(self.scopes) ]))
+
+    def functionsToString(self):
+        return "Functions:\n" + ("\n".join([ f"  {function.name}(...)" for function in self.functions ]))
+
+    def methodsToString(self):
+        return "Methods:\n" + ("\n".join([f"  {function.name}(...)" for function in self.methods]))
+
+
+    def __str__(self):
+        return self.scopesToString() + self.functionsToString() + self.methodsToString()
+
+    def __repr__(self):
+        return self.__str__()
\ No newline at end of file
diff --git a/smnp/environment/factory.py b/smnp/environment/factory.py
index 2a10ed1..9ee701d 100644
--- a/smnp/environment/factory.py
+++ b/smnp/environment/factory.py
@@ -1,6 +1,8 @@
 from smnp.environment.environment import Environment
 from smnp.library.function import display, sleep, semitones, interval, combine, flat, wait, rand, tuplet, synth, pause, \
-    transpose, type, exit, duration, octave
+    transpose, type, exit, duration, octave, debug
+from smnp.type.model import Type
+from smnp.type.value import Value
 
 
 def createEnvironment():
@@ -18,7 +20,8 @@ def createEnvironment():
         tuplet.function,
         synth.function,
         pause.function,
-        transpose.function
+        transpose.function,
+        debug.function
     ]
 
     methods = [
@@ -27,7 +30,7 @@ def createEnvironment():
     ]
 
     variables = {
-        "bpm": 120
+        "bpm": Value(Type.INTEGER, 120)
     }
 
     return Environment([ variables ], functions, methods)
diff --git a/smnp/error/base.py b/smnp/error/base.py
index e7aaa6f..751e110 100644
--- a/smnp/error/base.py
+++ b/smnp/error/base.py
@@ -1,2 +1,13 @@
 class SmnpException(Exception):
-    pass
\ No newline at end of file
+    def __init__(self, msg, pos):
+        self.msg = msg
+        self.pos = pos
+
+    def _title(self):
+        pass
+
+    def _position(self):
+        return "" if self.pos is None else f" [line {self.pos[0]+1}, col {self.pos[1]+1}]"
+
+    def message(self):
+        return f"{self._title()}{self._position()}:\n{self.msg}"
diff --git a/smnp/error/function.py b/smnp/error/function.py
index 1d14789..d8eb957 100644
--- a/smnp/error/function.py
+++ b/smnp/error/function.py
@@ -2,20 +2,32 @@ from smnp.error.base import SmnpException
 
 
 class IllegalFunctionInvocationException(SmnpException):
-    def __init__(self, expected, found):
-        self.msg = f"Illegal function invocation\n\nExpected signature:\n{expected}\n\nFound:\n{found}"
+    def __init__(self, expected, found, pos=None):
+        super().__init__(f"Expected signature:\n{expected}\n\nFound:\n{found}", pos)
+
+    def _title(self):
+        return "Invocation Error"
 
 
 class FunctionNotFoundException(SmnpException):
-    def __init__(self, function):
-        self.msg = f"Function '{function}' not found"
+    def __init__(self, function, pos=None):
+        super().__init__(f"Function '{function}' not found", pos)
+
+    def _title(self):
+        return "Invocation Error"
 
 
 class MethodNotFoundException(SmnpException):
-    def __init__(self, object, method):
-        self.msg = f"Method '{method}' of type '{object}' not found"
+    def __init__(self, object, method, pos=None):
+        super().__init__(f"Method '{method}' of type '{object}' not found", pos)
+
+    def _title(self):
+        return "Invocation Error"
 
 
 class IllegalArgumentException(SmnpException):
-    def __init__(self, msg):
-        self.msg = msg
\ No newline at end of file
+    def __init__(self, msg, pos=None):
+        super().__init__(msg, pos)
+
+    def _title(self):
+        return "Argument Error"
\ No newline at end of file
diff --git a/smnp/error/runtime.py b/smnp/error/runtime.py
index dbf2745..852b397 100644
--- a/smnp/error/runtime.py
+++ b/smnp/error/runtime.py
@@ -2,6 +2,12 @@ from smnp.error.base import SmnpException
 
 
 class RuntimeException(SmnpException):
-    def __init__(self, pos, msg):
-        posStr = "" if pos is None else f" [line {pos[0]+1}, col {pos[1]+1}]"
-        self.msg = f"Runtime error{posStr}:\n{msg}"
+    def __init__(self, msg, pos):
+        super().__init__(msg, pos)
+
+    def _title(self):
+        return "Runtime Error"
+
+    # def message(self):
+    #     posStr = "" if self.pos is None else f" [line {self.pos[0] + 1}, col {self.pos[1] + 1}]"
+    #     return f"Runtime error{posStr}:\n{self.mmsg}"
diff --git a/smnp/error/syntax.py b/smnp/error/syntax.py
index 4358a86..8ebbd64 100644
--- a/smnp/error/syntax.py
+++ b/smnp/error/syntax.py
@@ -2,6 +2,9 @@ from smnp.error.base import SmnpException
 
 
 class SyntaxException(SmnpException):
-    def __init__(self, pos, msg):        
-        posStr = "" if pos is None else f" [line {pos[0]+1}, col {pos[1]+1}]"
-        self.msg = f"Syntax error{posStr}:\n{msg}"
+    def __init__(self, msg, pos=None):
+        super().__init__(msg, pos)
+
+    def _title(self):
+        return "Syntax Error"
+
diff --git a/smnp/library/function/debug.py b/smnp/library/function/debug.py
new file mode 100644
index 0000000..941e8b3
--- /dev/null
+++ b/smnp/library/function/debug.py
@@ -0,0 +1,24 @@
+from smnp.error.function import IllegalArgumentException
+from smnp.library.model import Function
+from smnp.library.signature import signature, ofTypes
+from smnp.type.model import Type
+
+_signature = signature(ofTypes(Type.STRING))
+def _function(env, parameter):
+    if parameter.value == "environment":
+        print(env)
+        return
+    elif parameter.value == "variables":
+        print(env.scopesToString())
+        return
+    elif parameter.value == "functions":
+        print(env.functionsToString())
+        return
+    elif parameter.value == "methods":
+        print(env.methodsToString())
+        return
+
+    raise IllegalArgumentException(f"Unknown parameter '{parameter.value}'")
+
+
+function = Function(_signature, _function, 'debug')
\ No newline at end of file
diff --git a/smnp/library/function/pause.py b/smnp/library/function/pause.py
index e3edd5a..3e7b9bf 100644
--- a/smnp/library/function/pause.py
+++ b/smnp/library/function/pause.py
@@ -7,7 +7,7 @@ from smnp.type.model import Type
 _signature = signature(ofTypes(Type.INTEGER))
 def _function(env, value):
     bpm = env.findVariable('bpm')
-    player.pause(value.value, bpm)
+    player.pause(value.value, bpm.value)
 
 
 function = Function(_signature, _function, 'pause')
\ No newline at end of file
diff --git a/smnp/library/function/synth.py b/smnp/library/function/synth.py
index 263009e..21bf1bf 100644
--- a/smnp/library/function/synth.py
+++ b/smnp/library/function/synth.py
@@ -8,7 +8,7 @@ _signature1 = varargSignature(ofTypes(Type.NOTE, Type.INTEGER))
 def _function1(env, vararg):
     notes = [arg.value for arg in vararg]
     bpm = env.findVariable('bpm')
-    playNotes(notes, bpm)
+    playNotes(notes, bpm.value)
 
 
 _signature2 = varargSignature(listOf(Type.NOTE, Type.INTEGER))
diff --git a/smnp/library/function/tuplet.py b/smnp/library/function/tuplet.py
index 47608ec..616953a 100644
--- a/smnp/library/function/tuplet.py
+++ b/smnp/library/function/tuplet.py
@@ -18,6 +18,6 @@ def _function2(env, n, m, notes):
 
 function = CombinedFunction(
     'tuplet',
-    Function(_function1, _function1),
-    Function(_function2, _function2)
+    Function(_signature1, _function1),
+    Function(_signature2, _function2)
 )
diff --git a/smnp/main.py b/smnp/main.py
index 2febc1b..008df09 100644
--- a/smnp/main.py
+++ b/smnp/main.py
@@ -1,29 +1,26 @@
 import sys
-from smnp.error.syntax import SyntaxException
-from smnp.error.runtime import RuntimeException
-from smnp.token.tokenizer import tokenize
+
 from smnp.ast.parser import parse
-#from Tokenizer import tokenize
-#from Evaluator import evaluate
-#from Environment import createEnvironment
-#from Error import SyntaxException, RuntimeException
+from smnp.environment.factory import createEnvironment
+from smnp.error.base import SmnpException
+from smnp.runtime.evaluator import evaluate
+from smnp.token.tokenizer import tokenize
+
 
 def main():
     try:
         with open(sys.argv[1], 'r') as source:
             lines = [line.rstrip('\n') for line in source.readlines()]
 
-        #env = createEnvironment()
-
         tokens = tokenize(lines)
 
         ast = parse(tokens)
 
-        #evaluate(ast, env)
-    except SyntaxException as e:
-        print(e.msg)
-    except RuntimeException as e:
-        print(e.msg)
+        env = createEnvironment()
+
+        evaluate(ast, env)
+
+    except SmnpException as e:
+        print(e.message())
     except KeyboardInterrupt:
         print("Program interrupted")
-
diff --git a/smnp/note/pitch.py b/smnp/note/pitch.py
index c9ef7d9..333b5e8 100644
--- a/smnp/note/pitch.py
+++ b/smnp/note/pitch.py
@@ -1,6 +1,8 @@
 from enum import Enum
+
 from smnp.error.syntax import SyntaxException
 
+
 class NotePitch(Enum):
     C = 0
     CIS = 1
@@ -46,7 +48,7 @@ class NotePitch(Enum):
         try:            
             return stringToPitch[string.lower()]
         except KeyError as e:
-            raise SyntaxException(None, f"Note '{string}' does not exist")
+            raise SyntaxException(f"Note '{string}' does not exist") #TODO jakis inny exception
 
 stringToPitch = {
     'c': NotePitch.C,
diff --git a/smnp/runtime/evaluator.py b/smnp/runtime/evaluator.py
new file mode 100644
index 0000000..40a93cb
--- /dev/null
+++ b/smnp/runtime/evaluator.py
@@ -0,0 +1,57 @@
+from smnp.ast.node.access import AccessNode
+from smnp.ast.node.assignment import AssignmentNode
+from smnp.ast.node.asterisk import AsteriskNode
+from smnp.ast.node.block import BlockNode
+from smnp.ast.node.colon import ColonNode
+from smnp.ast.node.function import FunctionDefinitionNode, FunctionCallNode
+from smnp.ast.node.identifier import IdentifierNode
+from smnp.ast.node.integer import IntegerLiteralNode
+from smnp.ast.node.list import ListNode
+from smnp.ast.node.note import NoteLiteralNode
+from smnp.ast.node.percent import PercentNode
+from smnp.ast.node.program import Program
+from smnp.ast.node.string import StringLiteralNode
+
+def evaluate(input, environment):
+    from smnp.runtime.evaluators.access import evaluateAccess
+    from smnp.runtime.evaluators.assignment import evaluateAssignment
+    from smnp.runtime.evaluators.asterisk import evaluateAsterisk
+    from smnp.runtime.evaluators.block import evaluateBlock
+    from smnp.runtime.evaluators.colon import evaluateColon
+    from smnp.runtime.evaluators.function import evaluateFunctionDefinition, evaluateFunctionCall
+    from smnp.runtime.evaluators.identifier import evaluateIdentifier
+    from smnp.runtime.evaluators.integer import evaluateInteger
+    from smnp.runtime.evaluators.list import evaluateList
+    from smnp.runtime.evaluators.note import evaluateNote
+    from smnp.runtime.evaluators.percent import evaluatePercent
+    from smnp.runtime.evaluators.program import evaluateProgram
+    from smnp.runtime.evaluators.string import evaluateString
+
+    if isinstance(input, Program):
+        return evaluateProgram(input, environment)
+    if isinstance(input, IntegerLiteralNode):
+        return evaluateInteger(input, environment)
+    if isinstance(input, PercentNode):
+        return evaluatePercent(input, environment)
+    if isinstance(input, StringLiteralNode):
+        return evaluateString(input, environment)
+    if isinstance(input, NoteLiteralNode):
+        return evaluateNote(input, environment)
+    if isinstance(input, FunctionDefinitionNode):
+        return evaluateFunctionDefinition(input, environment)
+    if isinstance(input, FunctionCallNode):
+        return evaluateFunctionCall(input, environment)
+    if isinstance(input, AccessNode):
+        return evaluateAccess(input, environment)
+    if isinstance(input, BlockNode):
+        return evaluateBlock(input, environment)
+    if isinstance(input, ListNode):
+        return evaluateList(input, environment)
+    if isinstance(input, AssignmentNode):
+        return evaluateAssignment(input, environment)
+    if isinstance(input, AsteriskNode):
+        return evaluateAsterisk(input, environment)
+    if isinstance(input, ColonNode):
+        return evaluateColon(input, environment)
+    if isinstance(input, IdentifierNode):
+        return evaluateIdentifier(input, environment)
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/__init__.py b/smnp/runtime/evaluators/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/smnp/runtime/evaluators/access.py b/smnp/runtime/evaluators/access.py
new file mode 100644
index 0000000..06ece67
--- /dev/null
+++ b/smnp/runtime/evaluators/access.py
@@ -0,0 +1,33 @@
+from smnp.error.runtime import RuntimeException
+from smnp.runtime.evaluators.list import evaluateList
+
+
+def evaluateAccess(access, environment):
+    pass
+    #element = evaluate(access.element, environment)
+    # TODO: narazie tylko metody działają
+    #e = evaluateMethodCall(element, access.property, environment)
+
+
+
+def evaluateMethodCall(element, functionCall, environment):
+    funcName = functionCall.identifier.identifier
+    arguments = evaluateList(functionCall.arguments, environment)
+    arguments.insert(0, element)
+    # for name, library in environment.customFunctions.items():
+    # if funcName == name:
+    # if len(library['params']) != len(arguments):
+    # raise RuntimeException(functionCall.pos, f"Calling '{funcName}' requires {len(library['params'])} and {len(arguments)} was passed")
+    # environment.scopes.append({ library['params'][i].identifier: v for i, v in enumerate(arguments) })
+    # returnValue = None
+    # for node in library['body']:
+    # if not isinstance(node, ReturnNode):
+    # evaluate(node, environment)
+    # else:
+    # returnValue = evaluateReturn(node, environment)
+    # environment.scopes.pop(-1)
+    # return returnValue
+    for name, definition in environment.methods[type(element)].items():
+        if name == funcName:
+            return definition(arguments, environment)
+    raise RuntimeException(f"Method '{funcName}' does not exist", functionCall.pos)
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/assignment.py b/smnp/runtime/evaluators/assignment.py
new file mode 100644
index 0000000..3dcca70
--- /dev/null
+++ b/smnp/runtime/evaluators/assignment.py
@@ -0,0 +1,15 @@
+from smnp.error.runtime import RuntimeException
+from smnp.runtime.evaluator import evaluate
+from smnp.type.model import Type
+
+
+def evaluateAssignment(assignment, environment):
+    target = assignment.target.identifier
+    value = evaluate(assignment.value, environment)
+    if value.type == Type.VOID:
+        raise RuntimeException(f"Expected expression, found '{value.type.name}'", assignment.value.pos)
+    scopeOfExistingVariable = environment.findVariableScope(target)
+    if scopeOfExistingVariable is not None:
+        scopeOfExistingVariable[target] = value
+    else:
+        environment.scopes[-1][target] = value
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/asterisk.py b/smnp/runtime/evaluators/asterisk.py
new file mode 100644
index 0000000..ce390d2
--- /dev/null
+++ b/smnp/runtime/evaluators/asterisk.py
@@ -0,0 +1,48 @@
+from smnp.ast.node.identifier import IdentifierNode
+from smnp.runtime.evaluator import evaluate
+from smnp.type.model import Type
+from smnp.type.value import Value
+
+
+def evaluateAsterisk(asterisk, environment):
+    iterator = evaluate(asterisk.iterator, environment)
+    if iterator.type == Type.INTEGER:
+        evaluateAsteriskForNumber(asterisk, environment, iterator)
+
+    if iterator.type == Type.LIST:
+        evaluateAsteriskForList(asterisk, environment, iterator)
+
+
+
+def evaluateAsteriskForNumber(asterisk, environment, count):
+    for i in range(count.value):
+        if type(asterisk.iterator) == IdentifierNode:
+            environment.scopes[-1][f"_{asterisk.iterator.identifier}"] = Value(Type.INTEGER, i+1)
+        else:
+            environment.scopes[-1]["_"] = Value(Type.INTEGER, i+1)
+
+        evaluate(asterisk.statement, environment)
+
+    if type(asterisk.iterator) == IdentifierNode:
+        del environment.scopes[-1][f"_{asterisk.iterator.identifier}"]
+    else:
+        del environment.scopes[-1]["_"]
+
+
+def evaluateAsteriskForList(asterisk, environment, list):
+    for i, v in enumerate(list.value):
+        if type(asterisk.iterator) == IdentifierNode:
+            environment.scopes[-1][f"_{asterisk.iterator.identifier}"] = Value(Type.INTEGER, i+1)
+            environment.scopes[-1][f"{asterisk.iterator.identifier}_"] = v
+        else:
+            environment.scopes[-1]["_"] = Value(Type.INTEGER, i+1)
+            environment.scopes[-1]["__"] = v
+
+        evaluate(asterisk.statement, environment)
+
+        if type(asterisk.iterator) == IdentifierNode:
+            del environment.scopes[-1][f"_{asterisk.iterator.identifier}"]
+            del environment.scopes[-1][f"{asterisk.iterator.identifier}_"]
+        else:
+            del environment.scopes[-1]["_"]
+            del environment.scopes[-1]["__"]
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/block.py b/smnp/runtime/evaluators/block.py
new file mode 100644
index 0000000..f8b2b1e
--- /dev/null
+++ b/smnp/runtime/evaluators/block.py
@@ -0,0 +1,11 @@
+from smnp.runtime.evaluator import evaluate
+from smnp.runtime.tools import flatListNode
+
+
+def evaluateBlock(block, environment):
+    environment.scopes.append({})
+    for node in flatListNode(block):
+        evaluate(node, environment)
+    environment.scopes.pop(-1)
+
+
diff --git a/smnp/runtime/evaluators/colon.py b/smnp/runtime/evaluators/colon.py
new file mode 100644
index 0000000..ff1bbc0
--- /dev/null
+++ b/smnp/runtime/evaluators/colon.py
@@ -0,0 +1,16 @@
+from smnp.ast.node.integer import IntegerLiteralNode
+from smnp.ast.node.note import NoteLiteralNode
+from smnp.error.runtime import RuntimeException
+from smnp.note.model import Note
+from smnp.type.model import Type
+from smnp.type.value import Value
+
+
+def evaluateColon(colon, environment):
+    if isinstance(colon.a, NoteLiteralNode) and isinstance(colon.b, NoteLiteralNode):
+        return Value(Type.LIST, [Value(Type.NOTE, n) for n in Note.range(colon.a.value, colon.b.value)])
+
+    elif isinstance(colon.a, IntegerLiteralNode) and isinstance(colon.b, IntegerLiteralNode):
+        return Value(Type.LIST, [Value(Type.INTEGER, i) for i in range(colon.a.value, colon.b.value + 1)])
+
+    raise RuntimeException("Invalid colon arguments", colon.pos)
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/function.py b/smnp/runtime/evaluators/function.py
new file mode 100644
index 0000000..2ff6ab3
--- /dev/null
+++ b/smnp/runtime/evaluators/function.py
@@ -0,0 +1,54 @@
+from smnp.ast.node.identifier import IdentifierNode
+from smnp.ast.node.program import Program
+from smnp.error.runtime import RuntimeException
+from smnp.runtime.evaluators.list import evaluateList
+from smnp.runtime.tools import flatListNode
+
+
+def evaluateFunctionDefinition(definition, environment):
+    name = definition.name
+    params = list([p for p in flatListNode(definition.parameters)])
+    body = definition.body
+
+    if not isinstance(definition.parent, Program):
+        raise RuntimeException(f"Functions can be defined only on the top level of script", name.pos)
+
+    for p in params:
+        if not isinstance(p, IdentifierNode):
+            raise RuntimeException("Parameter of function definition must be an identifier", p.pos, )
+
+    if name.identifier in environment.customFunctions or name.identifier in environment.functions:
+        raise RuntimeException(f"Function '{name.identifier}' already exists", name.pos)
+
+    environment.customFunctions[name.identifier] = {
+        'params': params,
+        'body': flatListNode(body)
+    }
+
+
+def evaluateFunctionCall(functionCall, environment):
+    functionName = functionCall.identifier.identifier
+    arguments = evaluateList(functionCall.arguments, environment).value
+    return environment.invokeFunction(functionName, arguments)
+
+
+# def evaluateFunctionCall(functionCall, environment):
+#     funcName = functionCall.identifier.identifier
+#     arguments = evaluateList(functionCall.arguments, environment)
+#     for name, function in environment.customFunctions.items():
+#         if funcName == name:
+#             if len(function['params']) != len(arguments):
+#                 raise RuntimeException(functionCall.pos, f"Calling '{funcName}' requires {len(function['params'])} and {len(arguments)} was passed")
+#             environment.scopes.append({ function['params'][i].identifier: v for i, v in enumerate(arguments) })
+#             returnValue = None
+#             for node in function['body']:
+#                 if not isinstance(node, ReturnNode):
+#                     evaluate(node, environment)
+#                 else:
+#                     returnValue = evaluateReturn(node, environment)
+#             environment.scopes.pop(-1)
+#             return returnValue
+#     for name, definition in environment.functions.items():
+#         if name == funcName:
+#             return definition(arguments, environment)
+#     raise RuntimeException(functionCall.pos, f"Function '{funcName}' does not exist")
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/identifier.py b/smnp/runtime/evaluators/identifier.py
new file mode 100644
index 0000000..7cd3a41
--- /dev/null
+++ b/smnp/runtime/evaluators/identifier.py
@@ -0,0 +1,10 @@
+from smnp.error.runtime import RuntimeException
+
+
+def evaluateIdentifier(identifier, environment):
+    try:
+        value = environment.findVariable(identifier.identifier)
+        return value
+    except RuntimeException as e:
+        e.pos = identifier.pos
+        raise e
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/integer.py b/smnp/runtime/evaluators/integer.py
new file mode 100644
index 0000000..ff3b3f6
--- /dev/null
+++ b/smnp/runtime/evaluators/integer.py
@@ -0,0 +1,6 @@
+from smnp.type.model import Type
+from smnp.type.value import Value
+
+
+def evaluateInteger(integer, environment):
+    return Value(Type.INTEGER, integer.value)
diff --git a/smnp/runtime/evaluators/list.py b/smnp/runtime/evaluators/list.py
new file mode 100644
index 0000000..74def39
--- /dev/null
+++ b/smnp/runtime/evaluators/list.py
@@ -0,0 +1,17 @@
+from smnp.error.runtime import RuntimeException
+from smnp.runtime.evaluator import evaluate
+from smnp.runtime.tools import flatListNode
+from smnp.type.model import Type
+from smnp.type.value import Value
+
+
+def evaluateList(list, environment):
+    newList = []
+    for elem in flatListNode(list):
+        item = evaluate(elem, environment)
+        if item.type == Type.VOID:
+            raise RuntimeException(f"Expected expression, found '{item.type.name}'", elem.pos)
+        newList.append(item)
+    return Value(Type.LIST, newList)
+
+
diff --git a/smnp/runtime/evaluators/note.py b/smnp/runtime/evaluators/note.py
new file mode 100644
index 0000000..77a3fc6
--- /dev/null
+++ b/smnp/runtime/evaluators/note.py
@@ -0,0 +1,6 @@
+from smnp.type.model import Type
+from smnp.type.value import Value
+
+
+def evaluateNote(note, environment):
+    return Value(Type.NOTE, note.value)
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/percent.py b/smnp/runtime/evaluators/percent.py
new file mode 100644
index 0000000..41bacd5
--- /dev/null
+++ b/smnp/runtime/evaluators/percent.py
@@ -0,0 +1,6 @@
+from smnp.type.model import Type
+from smnp.type.value import Value
+
+
+def evaluatePercent(percent, environment):
+    return Value(Type.PERCENT, percent.value.value * 0.01)
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/program.py b/smnp/runtime/evaluators/program.py
new file mode 100644
index 0000000..a9e9b20
--- /dev/null
+++ b/smnp/runtime/evaluators/program.py
@@ -0,0 +1,6 @@
+from smnp.runtime.evaluator import evaluate
+
+
+def evaluateProgram(program, environment):
+    for node in program.children:
+        evaluate(node, environment)
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/ret.py b/smnp/runtime/evaluators/ret.py
new file mode 100644
index 0000000..b85ed79
--- /dev/null
+++ b/smnp/runtime/evaluators/ret.py
@@ -0,0 +1,5 @@
+from smnp.runtime.evaluator import evaluate
+
+
+def evaluateReturn(returnNode, environment):
+    return evaluate(returnNode.value, environment)
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/string.py b/smnp/runtime/evaluators/string.py
new file mode 100644
index 0000000..1da5f09
--- /dev/null
+++ b/smnp/runtime/evaluators/string.py
@@ -0,0 +1,28 @@
+import re
+
+from smnp.error.runtime import RuntimeException
+from smnp.type.model import Type
+from smnp.type.value import Value
+
+
+def evaluateString(string, environment):
+    value = interpolate(string, environment)
+    return Value(Type.STRING, value)
+
+
+def interpolate(string, environment):
+    interpolated = string.value
+    for scope in reversed(environment.scopes):
+        for name, value in scope.items():
+            interpolated = interpolated.replace('{' + name + '}', value.stringify())
+
+    nonMatchedVariables = re.findall(r"\{\w+\}", interpolated)
+    if len(nonMatchedVariables) > 0:
+        raise RuntimeException(f"Variable '{nonMatchedVariables[0][1:len(nonMatchedVariables[0])-1]}' is not declared",
+                               (string.pos[0], string.pos[1] + string.value.find(nonMatchedVariables[0])+1))
+
+    return interpolated
+
+# or scope in reversed(environment.scopes):
+#         for k, v in scope.items():
+#             value = value.replace('{' + k + '}', v) #TODO: poprawic
\ No newline at end of file
diff --git a/smnp/runtime/tools.py b/smnp/runtime/tools.py
new file mode 100644
index 0000000..75ca159
--- /dev/null
+++ b/smnp/runtime/tools.py
@@ -0,0 +1,13 @@
+def flatListNode(listNode):
+    if len(listNode.children[0].children) == 1:
+        return []
+    return _flatListNode(listNode.children[0], [])
+
+
+def _flatListNode(listItemNode, list = []):
+    if len(listItemNode.children) == 2:
+        value = listItemNode.children[0]
+        next = listItemNode.children[1]
+        list.append(value)
+        _flatListNode(next, list)
+    return list
diff --git a/smnp/token/tokenizer.py b/smnp/token/tokenizer.py
index 7e3322d..c49b47e 100644
--- a/smnp/token/tokenizer.py
+++ b/smnp/token/tokenizer.py
@@ -1,27 +1,24 @@
-import sys
-import time
-import re
 from smnp.error.syntax import SyntaxException
-from smnp.token.type import TokenType
-from smnp.token.model import Token, TokenList
-from smnp.token.tools import tokenizeChar, tokenizeRegexPattern
-from smnp.token.tokenizers.paren import tokenizeOpenParen, tokenizeCloseParen
-from smnp.token.tokenizers.asterisk import tokenizeAsterisk
-from smnp.token.tokenizers.whitespace import tokenizeWhitespaces
-from smnp.token.tokenizers.identifier import tokenizeIdentifier
-from smnp.token.tokenizers.comma import tokenizeComma
-from smnp.token.tokenizers.string import tokenizeString
-from smnp.token.tokenizers.integer import tokenizeInteger
-from smnp.token.tokenizers.bracket import tokenizeOpenBracket, tokenizeCloseBracket
+from smnp.error.syntax import SyntaxException
+from smnp.token.model import TokenList
 from smnp.token.tokenizers.assign import tokenizeAssign
+from smnp.token.tokenizers.asterisk import tokenizeAsterisk
+from smnp.token.tokenizers.bracket import tokenizeOpenBracket, tokenizeCloseBracket
 from smnp.token.tokenizers.colon import tokenizeColon
+from smnp.token.tokenizers.comma import tokenizeComma
 from smnp.token.tokenizers.comment import tokenizeComment
-from smnp.token.tokenizers.note import tokenizeNote
-from smnp.token.tokenizers.function import tokenizeFunction
-from smnp.token.tokenizers.ret import tokenizeReturn
-from smnp.token.tokenizers.percent import tokenizePercent
-from smnp.token.tokenizers.minus import tokenizeMinus
 from smnp.token.tokenizers.dot import tokenizeDot
+from smnp.token.tokenizers.function import tokenizeFunction
+from smnp.token.tokenizers.identifier import tokenizeIdentifier
+from smnp.token.tokenizers.integer import tokenizeInteger
+from smnp.token.tokenizers.minus import tokenizeMinus
+from smnp.token.tokenizers.note import tokenizeNote
+from smnp.token.tokenizers.paren import tokenizeOpenParen, tokenizeCloseParen
+from smnp.token.tokenizers.percent import tokenizePercent
+from smnp.token.tokenizers.ret import tokenizeReturn
+from smnp.token.tokenizers.string import tokenizeString
+from smnp.token.tokenizers.whitespace import tokenizeWhitespaces
+from smnp.token.type import TokenType
 
 tokenizers = (
     tokenizeOpenParen, 
@@ -58,7 +55,7 @@ def tokenize(lines):
             consumedChars, token = combinedTokenizer(line, current, lineNumber)            
             
             if consumedChars == 0:
-                raise SyntaxException((lineNumber, current), f"Unknown symbol '{line[current]}'")
+                raise SyntaxException(f"Unknown symbol '{line[current]}'", (lineNumber, current))
             
             current += consumedChars
             tokens.append(token)
diff --git a/smnp/type/model.py b/smnp/type/model.py
index b0bb010..73a2122 100644
--- a/smnp/type/model.py
+++ b/smnp/type/model.py
@@ -17,7 +17,7 @@ class Type(Enum):
 
 
 def _failStringify(t):
-    raise RuntimeException(None, f"Not able to interpret {t.name}'")
+    raise RuntimeException(f"Not able to interpret {t.name}'")