Major overhaul of function type checking, allow static and dynamic as well as variadic argument lists

Split 'Function' class into abstract superclass 'Function' and child classes 'UserDefinedFunction' and 'BuiltinFunction'

24 files changed, 344 insertions, 80 deletions

diff --git a/src/main/com/jantuomi/tunkki/core/parser/ast/FunctionDefineNode.java b/src/main/com/jantuomi/tunkki/core/parser/ast/FunctionDefineNode.java
index 19de2f2..27f3a3c 100644
--- a/src/main/com/jantuomi/tunkki/core/parser/ast/FunctionDefineNode.java
+++ b/src/main/com/jantuomi/tunkki/core/parser/ast/FunctionDefineNode.java
@@ -2,8 +2,7 @@ package com.jantuomi.tunkki.core.parser.ast;
 
 import com.jantuomi.tunkki.core.parser.datatype.CallableDatatype;
 import com.jantuomi.tunkki.core.parser.datatype.Datatype;
-import com.jantuomi.tunkki.core.runtime.Function;
-import com.jantuomi.tunkki.core.runtime.State;
+import com.jantuomi.tunkki.core.runtime.UserDefinedFunction;
 import com.jantuomi.tunkki.core.parser.tokenizer.token.Token;
 import com.jantuomi.tunkki.exception.types.ExpectedDifferentTokenTunkkiError;
 import com.jantuomi.tunkki.exception.types.TunkkiError;
@@ -38,7 +37,7 @@ public class FunctionDefineNode extends VarargOperatorNode {
         catch (Exception ex) {
             throw new ExpectedDifferentTokenTunkkiError(getLine(), getText());
         }
-        Function function = new Function(argumentNames, (BlockBodyNode) body);
+        UserDefinedFunction function = new UserDefinedFunction(argumentNames, (BlockBodyNode) body);
 
         CallableDatatype c = new CallableDatatype();
         c.setData(function);
@@ -52,7 +51,7 @@ public class FunctionDefineNode extends VarargOperatorNode {
             System.out.print("\t");
         }
 
-        System.out.println(String.format("Function"));
+        System.out.println(String.format("UserDefinedFunction"));
 
         for (int i = 0; i < indent + 1; i++) {
             System.out.print("\t");
diff --git a/src/main/com/jantuomi/tunkki/core/parser/datatype/BooleanDatatype.java b/src/main/com/jantuomi/tunkki/core/parser/datatype/BooleanDatatype.java
index d00b42a..df0e572 100644
--- a/src/main/com/jantuomi/tunkki/core/parser/datatype/BooleanDatatype.java
+++ b/src/main/com/jantuomi/tunkki/core/parser/datatype/BooleanDatatype.java
@@ -23,27 +23,27 @@ public class BooleanDatatype extends Datatype<Boolean> {
     }
 
     @Override
-    public Datatype<Boolean> add(Datatype<Boolean> other) throws TunkkiError {
+    public Datatype add(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public Datatype<Boolean> subtract(Datatype<Boolean> other) throws TunkkiError {
+    public Datatype subtract(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public Datatype<Boolean> multiply(Datatype<Boolean> other) throws TunkkiError {
+    public Datatype multiply(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public Datatype<Boolean> divide(Datatype<Boolean> other) throws TunkkiError {
+    public Datatype divide(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public BooleanDatatype equals(Datatype<Boolean> other) throws TunkkiError {
+    public BooleanDatatype equals(Datatype other) throws TunkkiError {
         switch (other.getType()) {
             case Boolean:
                 return new BooleanDatatype(getData().equals(other.getData()));
diff --git a/src/main/com/jantuomi/tunkki/core/parser/datatype/CallableDatatype.java b/src/main/com/jantuomi/tunkki/core/parser/datatype/CallableDatatype.java
index f05ee72..8ee4148 100644
--- a/src/main/com/jantuomi/tunkki/core/parser/datatype/CallableDatatype.java
+++ b/src/main/com/jantuomi/tunkki/core/parser/datatype/CallableDatatype.java
@@ -1,6 +1,7 @@
 package com.jantuomi.tunkki.core.parser.datatype;
 
 import com.jantuomi.tunkki.core.runtime.Function;
+import com.jantuomi.tunkki.core.runtime.UserDefinedFunction;
 import com.jantuomi.tunkki.exception.types.TunkkiError;
 
 import java.util.List;
@@ -25,27 +26,27 @@ public class CallableDatatype extends Datatype<Function> {
     }
 
     @Override
-    public Datatype<Function> add(Datatype<Function> other) throws TunkkiError {
+    public Datatype add(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public Datatype<Function> subtract(Datatype<Function> other) throws TunkkiError {
+    public Datatype subtract(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public Datatype<Function> multiply(Datatype<Function> other) throws TunkkiError {
+    public Datatype multiply(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public Datatype<Function> divide(Datatype<Function> other) throws TunkkiError {
+    public Datatype divide(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public BooleanDatatype equals(Datatype<Function> other) throws TunkkiError {
+    public BooleanDatatype equals(Datatype other) throws TunkkiError {
         switch (other.getType()) {
             case Nada:
                 return new BooleanDatatype(false);
diff --git a/src/main/com/jantuomi/tunkki/core/parser/datatype/Datatype.java b/src/main/com/jantuomi/tunkki/core/parser/datatype/Datatype.java
index 928f74b..9983d64 100644
--- a/src/main/com/jantuomi/tunkki/core/parser/datatype/Datatype.java
+++ b/src/main/com/jantuomi/tunkki/core/parser/datatype/Datatype.java
@@ -37,11 +37,11 @@ abstract public class Datatype<T> {
     @Override
     abstract public String toString();
 
-    abstract public Datatype<T> add(Datatype<T> other) throws TunkkiError;
-    public abstract Datatype<T> subtract(Datatype<T> other) throws TunkkiError;
-    public abstract Datatype<T> multiply(Datatype<T> other) throws TunkkiError;
-    public abstract Datatype<T> divide(Datatype<T> other) throws TunkkiError;
-    public abstract BooleanDatatype equals(Datatype<T> other) throws TunkkiError;
+    abstract public Datatype add(Datatype other) throws TunkkiError;
+    public abstract Datatype subtract(Datatype other) throws TunkkiError;
+    public abstract Datatype multiply(Datatype other) throws TunkkiError;
+    public abstract Datatype divide(Datatype other) throws TunkkiError;
+    public abstract BooleanDatatype equals(Datatype other) throws TunkkiError;
 
     public static String toString(List<Datatype> variables) {
         String result = "[";
diff --git a/src/main/com/jantuomi/tunkki/core/parser/datatype/ListDatatype.java b/src/main/com/jantuomi/tunkki/core/parser/datatype/ListDatatype.java
index f097ee4..a3fb699 100644
--- a/src/main/com/jantuomi/tunkki/core/parser/datatype/ListDatatype.java
+++ b/src/main/com/jantuomi/tunkki/core/parser/datatype/ListDatatype.java
@@ -25,17 +25,17 @@ public class ListDatatype extends Datatype<List<Datatype>> {
     }
 
     @Override
-    public BooleanDatatype equals(Datatype<List<Datatype>> other) throws TunkkiError {
+    public BooleanDatatype equals(Datatype other) throws TunkkiError {
         switch (other.getType()) {
             case List:
                 boolean found = false;
                 for (int i = 0; i < getData().size(); i++) {
-                    if (!getData().get(i).equals(other.getData().get(i)).getData()) {
+                    if (!getData().get(i).equals(((ListDatatype) other).getData().get(i)).getData()) {
                         found = true;
                         break;
                     }
-                    return new BooleanDatatype(found);
                 }
+                return new BooleanDatatype(found);
             case Nada:
                 return new BooleanDatatype(false);
         }
diff --git a/src/main/com/jantuomi/tunkki/core/parser/datatype/NadaDatatype.java b/src/main/com/jantuomi/tunkki/core/parser/datatype/NadaDatatype.java
index 880d8ad..7b92f7a 100644
--- a/src/main/com/jantuomi/tunkki/core/parser/datatype/NadaDatatype.java
+++ b/src/main/com/jantuomi/tunkki/core/parser/datatype/NadaDatatype.java
@@ -18,31 +18,31 @@ public class NadaDatatype extends Datatype<Integer> {
     }
 
     @Override
-    public Datatype<Integer> add(Datatype<Integer> other) throws TunkkiError {
+    public Datatype add(Datatype other) throws TunkkiError {
         doOperation();
         return null;
     }
 
     @Override
-    public Datatype<Integer> subtract(Datatype<Integer> other) throws TunkkiError {
+    public Datatype subtract(Datatype other) throws TunkkiError {
         doOperation();
         return null;
     }
 
     @Override
-    public Datatype<Integer> multiply(Datatype<Integer> other) throws TunkkiError {
+    public Datatype multiply(Datatype other) throws TunkkiError {
         doOperation();
         return null;
     }
 
     @Override
-    public Datatype<Integer> divide(Datatype<Integer> other) throws TunkkiError {
+    public Datatype divide(Datatype other) throws TunkkiError {
         doOperation();
         return null;
     }
 
     @Override
-    public BooleanDatatype equals(Datatype<Integer> other) throws TunkkiError {
+    public BooleanDatatype equals(Datatype other) throws TunkkiError {
         if (other.getType() == Type.Nada) {
             return new BooleanDatatype(true);
         }
diff --git a/src/main/com/jantuomi/tunkki/core/parser/datatype/StringDatatype.java b/src/main/com/jantuomi/tunkki/core/parser/datatype/StringDatatype.java
index 4ffcb49..594de52 100644
--- a/src/main/com/jantuomi/tunkki/core/parser/datatype/StringDatatype.java
+++ b/src/main/com/jantuomi/tunkki/core/parser/datatype/StringDatatype.java
@@ -23,29 +23,29 @@ public class StringDatatype extends Datatype<String> {
     }
 
     @Override
-    public Datatype<String> add(Datatype<String> other) {
+    public Datatype add(Datatype other) {
         return new StringDatatype(
                 getData() + other.getData()
         );
     }
 
     @Override
-    public Datatype<String> subtract(Datatype<String> other) throws TunkkiError {
+    public Datatype subtract(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public Datatype<String> multiply(Datatype<String> other) throws TunkkiError {
+    public Datatype multiply(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public Datatype<String> divide(Datatype<String> other) throws TunkkiError {
+    public Datatype divide(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public BooleanDatatype equals(Datatype<String> other) throws TunkkiError {
+    public BooleanDatatype equals(Datatype other) throws TunkkiError {
         switch (other.getType()) {
             case String:
                 return new BooleanDatatype(getData().equals(other.getData()));
diff --git a/src/main/com/jantuomi/tunkki/core/parser/datatype/VoidDatatype.java b/src/main/com/jantuomi/tunkki/core/parser/datatype/VoidDatatype.java
index ae3c8f9..77dd356 100644
--- a/src/main/com/jantuomi/tunkki/core/parser/datatype/VoidDatatype.java
+++ b/src/main/com/jantuomi/tunkki/core/parser/datatype/VoidDatatype.java
@@ -18,27 +18,27 @@ public class VoidDatatype extends Datatype<Integer> {
     }
 
     @Override
-    public Datatype<Integer> add(Datatype<Integer> other) {
+    public Datatype add(Datatype other) {
         return null;
     }
 
     @Override
-    public Datatype<Integer> subtract(Datatype<Integer> other) {
+    public Datatype subtract(Datatype other) {
         return null;
     }
 
     @Override
-    public Datatype<Integer> multiply(Datatype<Integer> other) throws TunkkiError {
+    public Datatype multiply(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public Datatype<Integer> divide(Datatype<Integer> other) throws TunkkiError {
+    public Datatype divide(Datatype other) throws TunkkiError {
         return null;
     }
 
     @Override
-    public BooleanDatatype equals(Datatype<Integer> other) throws TunkkiError {
+    public BooleanDatatype equals(Datatype other) throws TunkkiError {
         return new BooleanDatatype(false);
     }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/Function.java b/src/main/com/jantuomi/tunkki/core/runtime/Function.java
index e4c4f0f..b6eab89 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/Function.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/Function.java
@@ -3,17 +3,17 @@ package com.jantuomi.tunkki.core.runtime;
 import com.jantuomi.tunkki.core.parser.ast.BlockBodyNode;
 import com.jantuomi.tunkki.core.parser.datatype.CallableDatatype;
 import com.jantuomi.tunkki.core.parser.datatype.Datatype;
+import com.jantuomi.tunkki.exception.types.FunctionArgumentTunkkiError;
 import com.jantuomi.tunkki.exception.types.TunkkiError;
 
-import java.util.List;
+import java.util.*;
 
 /**
- * Created by jan on 20.6.2016.
+ * Created by jan on 5.8.2016.
  */
-public class Function {
-
-    private List<String> argumentNames;
-    private BlockBodyNode body;
+abstract public class Function {
+    protected List<String> argumentNames;
+    protected BlockBodyNode body;
 
     public Function(List<String> argumentNames, BlockBodyNode body) {
         this.argumentNames = argumentNames;
@@ -23,26 +23,79 @@ public class Function {
     public Datatype evaluate(List<Datatype> params) throws TunkkiError {
         State.getInstance().createScope();
 
-        if (params.size() != argumentNames.size()) {
-            return null;
+        if (!checkArgumentListValidity(params)) {
+            throw new FunctionArgumentTunkkiError(-1, Datatype.toString(params));
         }
 
-        for (int i = 0; i < argumentNames.size(); i++) {
-            State.getInstance().addSymbolToScope(argumentNames.get(i));
-            State.getInstance().setSymbolValueToScope(argumentNames.get(i), params.get(i));
+        return null;
+    }
+
+    protected boolean checkArgumentListValidity(List<Datatype> params) throws FunctionArgumentTunkkiError {
+        int argumentCount = getArgumentCount();
+        boolean isSizeCorrect;
+        if (!hasVariableArgumentList()) {
+            isSizeCorrect = (argumentCount == params.size());
+        } else {
+            isSizeCorrect = true;
         }
 
-        Datatype returnValue = body.evaluate();
+        if (!isSizeCorrect) {
+            return false;
+        }
 
-        State.getInstance().popScope();
+        if (hasDynamicallyTypedArguments()) {
+            // do nothing if types can be whatever
+        } else {
+            List<Set<Datatype.Type>> argumentTypes = getArgumentTypes();
+            Set<Datatype.Type> acceptableTypes;
+            for (int i = 0; i < params.size(); i++) {
+                /* The first type set of the list should be tested against for all arguments
+                if the function's argument list is variable in size
+                 */
+                if (hasVariableArgumentList()) {
+                    acceptableTypes = argumentTypes.get(0);
+                } else {
+                    acceptableTypes = argumentTypes.get(i);
+                }
+                if (!acceptableTypes.contains(params.get(i).getType())) {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
 
-        return returnValue;
+    public int getArgumentCount() {
+        return argumentNames.size();
     }
 
+    abstract public boolean hasVariableArgumentList();
+
+    abstract public boolean hasDynamicallyTypedArguments();
+
+    /**
+     * Return a list of possible argument type sets for each positional argument
+     * If the function has variable arguments, the first (and only) list element set
+     * is tested against for all parameters
+     * @return A list of sets of acceptable datatypes for each argument, in order
+     */
+    abstract public List<Set<Datatype.Type>> getArgumentTypes();
+
     public CallableDatatype makeCallable() {
         CallableDatatype c = new CallableDatatype();
         c.setData(this);
         return c;
     }
 
+    protected Set<Datatype.Type> createAcceptableTypeSet(Datatype.Type... types) {
+        return new HashSet<>(Arrays.asList(types));
+    }
+
+    final protected Set<Datatype.Type> allTypesSet() {
+        return new HashSet<>(Arrays.asList(
+                Datatype.Type.Boolean, Datatype.Type.Double, Datatype.Type.Integer,
+                Datatype.Type.List, Datatype.Type.Nada, Datatype.Type.Object, Datatype.Type.String
+        ));
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/UserDefinedFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/UserDefinedFunction.java
new file mode 100644
index 0000000..2e994a8
--- /dev/null
+++ b/src/main/com/jantuomi/tunkki/core/runtime/UserDefinedFunction.java
@@ -0,0 +1,51 @@
+package com.jantuomi.tunkki.core.runtime;
+
+import com.jantuomi.tunkki.core.parser.ast.BlockBodyNode;
+import com.jantuomi.tunkki.core.parser.datatype.CallableDatatype;
+import com.jantuomi.tunkki.core.parser.datatype.Datatype;
+import com.jantuomi.tunkki.exception.types.FunctionArgumentTunkkiError;
+import com.jantuomi.tunkki.exception.types.TunkkiError;
+
+import java.util.*;
+
+/**
+ * Created by jan on 20.6.2016.
+ */
+public class UserDefinedFunction extends Function {
+
+
+    public UserDefinedFunction(List<String> argumentNames, BlockBodyNode body) {
+        super(argumentNames, body);
+    }
+
+    @Override
+    public Datatype evaluate(List<Datatype> params) throws TunkkiError {
+
+        super.evaluate(params);
+
+        for (int i = 0; i < argumentNames.size(); i++) {
+            State.getInstance().addSymbolToScope(argumentNames.get(i));
+            State.getInstance().setSymbolValueToScope(argumentNames.get(i), params.get(i));
+        }
+
+        Datatype returnValue = body.evaluate();
+        State.getInstance().popScope();
+
+        return returnValue;
+    }
+
+    @Override
+    public boolean hasVariableArgumentList() {
+        return false;
+    }
+
+    @Override
+    public boolean hasDynamicallyTypedArguments() {
+        return true;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Collections.emptyList();
+    }
+}
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/BuiltinManager.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/BuiltinManager.java
index ae66a14..eb7374d 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/BuiltinManager.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/BuiltinManager.java
@@ -1,7 +1,6 @@
 package com.jantuomi.tunkki.core.runtime.builtins;
 
 import com.jantuomi.tunkki.core.parser.datatype.CallableDatatype;
-import com.jantuomi.tunkki.core.runtime.Function;
 import com.jantuomi.tunkki.core.runtime.builtins.globals.*;
 import com.jantuomi.tunkki.core.runtime.builtins.globals.cast.AsBooleanBuiltinFunction;
 import com.jantuomi.tunkki.core.runtime.builtins.globals.cast.AsIntBuiltinFunction;
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/BuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/BuiltinFunction.java
index b175525..61d581b 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/BuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/BuiltinFunction.java
@@ -2,9 +2,11 @@ package com.jantuomi.tunkki.core.runtime.builtins.globals;
 
 import com.jantuomi.tunkki.core.parser.datatype.Datatype;
 import com.jantuomi.tunkki.core.runtime.Function;
+import com.jantuomi.tunkki.core.runtime.UserDefinedFunction;
 import com.jantuomi.tunkki.exception.types.TunkkiError;
 
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by jan on 28.6.2016.
@@ -15,5 +17,10 @@ abstract public class BuiltinFunction extends Function {
     }
 
     @Override
-    abstract public Datatype evaluate(List<Datatype> params) throws TunkkiError;
+    abstract public List<Set<Datatype.Type>> getArgumentTypes();
+
+    @Override
+    public boolean hasDynamicallyTypedArguments() {
+        return false;
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ConcatBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ConcatBuiltinFunction.java
index 170efed..bd0a627 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ConcatBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ConcatBuiltinFunction.java
@@ -4,8 +4,10 @@ import com.jantuomi.tunkki.core.parser.datatype.Datatype;
 import com.jantuomi.tunkki.core.parser.datatype.StringDatatype;
 import com.jantuomi.tunkki.exception.types.TunkkiError;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by jan on 21.6.2016.
@@ -19,6 +21,8 @@ public class ConcatBuiltinFunction extends BuiltinFunction {
 
     @Override
     public Datatype evaluate(List<Datatype> params) throws TunkkiError {
+        super.evaluate(params);
+
         StringBuilder sb = new StringBuilder();
         for (Datatype d : params) {
             sb.append(d.getData());
@@ -28,4 +32,16 @@ public class ConcatBuiltinFunction extends BuiltinFunction {
                 sb.toString()
         );
     }
+
+    @Override
+    public boolean hasVariableArgumentList() {
+        return true;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Arrays.asList(
+                createAcceptableTypeSet(Datatype.Type.String)
+        );
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ContainsBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ContainsBuiltinFunction.java
index ccb461a..5e1a9b0 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ContainsBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ContainsBuiltinFunction.java
@@ -9,6 +9,7 @@ import com.jantuomi.tunkki.exception.types.TunkkiError;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by jan on 27.7.2016.
@@ -20,9 +21,7 @@ public class ContainsBuiltinFunction extends BuiltinFunction {
 
     @Override
     public Datatype evaluate(List<Datatype> params) throws TunkkiError {
-        if (params.size() != 2) {
-            throw new FunctionArgumentTunkkiError(-1, Datatype.toString(params));
-        }
+        super.evaluate(params);
 
         if (params.get(0).getType() == Datatype.Type.List) {
             return evaluateOnList(params);
@@ -33,6 +32,19 @@ public class ContainsBuiltinFunction extends BuiltinFunction {
         throw new FunctionArgumentTunkkiError(-1, Datatype.toString(params));
     }
 
+    @Override
+    public boolean hasVariableArgumentList() {
+        return false;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Arrays.asList(
+                createAcceptableTypeSet(Datatype.Type.List, Datatype.Type.String),
+                createAcceptableTypeSet()
+        );
+    }
+
     private Datatype evaluateOnList(List<Datatype> params) throws TunkkiError {
         ListDatatype list = (ListDatatype) params.get(0);
         Datatype comp = params.get(1);
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/EqualsBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/EqualsBuiltinFunction.java
index c31759a..20e40fc 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/EqualsBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/EqualsBuiltinFunction.java
@@ -7,7 +7,9 @@ import com.jantuomi.tunkki.exception.types.TunkkiError;
 import com.jantuomi.tunkki.exception.types.TypeTunkkiError;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by jan on 31.7.2016.
@@ -19,9 +21,7 @@ public class EqualsBuiltinFunction extends BuiltinFunction {
 
     @Override
     public Datatype evaluate(List<Datatype> params) throws TunkkiError {
-        if (params.size() != 2) {
-            throw new FunctionArgumentTunkkiError(-1, Datatype.toString(params));
-        }
+        super.evaluate(params);
 
         Datatype lhs = params.get(0);
         Datatype rhs = params.get(1);
@@ -33,4 +33,19 @@ public class EqualsBuiltinFunction extends BuiltinFunction {
             throw new TypeTunkkiError(-1, lhs.getType().toString(), rhs.getType().toString());
         }
     }
+
+    @Override
+    public boolean hasVariableArgumentList() {
+        return false;
+    }
+
+    @Override
+    public boolean hasDynamicallyTypedArguments() {
+        return true;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Collections.emptyList();
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/GetBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/GetBuiltinFunction.java
index f936854..33a9170 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/GetBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/GetBuiltinFunction.java
@@ -9,6 +9,7 @@ import com.jantuomi.tunkki.exception.types.TunkkiError;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by jan on 28.7.2016.
@@ -42,4 +43,17 @@ public class GetBuiltinFunction extends BuiltinFunction {
             throw new OutOfBoundsTunkkiError(-1, index.toString());
         }
     }
+
+    @Override
+    public boolean hasVariableArgumentList() {
+        return false;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Arrays.asList(
+                createAcceptableTypeSet(Datatype.Type.List),
+                createAcceptableTypeSet(Datatype.Type.Integer)
+        );
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/IfBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/IfBuiltinFunction.java
index f794aa2..1156958 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/IfBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/IfBuiltinFunction.java
@@ -4,12 +4,14 @@ import com.jantuomi.tunkki.core.parser.datatype.BooleanDatatype;
 import com.jantuomi.tunkki.core.parser.datatype.CallableDatatype;
 import com.jantuomi.tunkki.core.parser.datatype.Datatype;
 import com.jantuomi.tunkki.core.parser.datatype.VoidDatatype;
+import com.jantuomi.tunkki.core.runtime.Function;
 import com.jantuomi.tunkki.exception.types.FunctionArgumentTunkkiError;
 import com.jantuomi.tunkki.exception.types.TunkkiError;
 
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by jan on 4.8.2016.
@@ -21,6 +23,8 @@ public class IfBuiltinFunction extends BuiltinFunction {
 
     @Override
     public Datatype evaluate(List<Datatype> params) throws TunkkiError {
+        super.evaluate(params);
+
         if (params.size() != 2) {
             throw new FunctionArgumentTunkkiError(-1, Datatype.toString(params));
         }
@@ -38,4 +42,17 @@ public class IfBuiltinFunction extends BuiltinFunction {
         }
         return new VoidDatatype();
     }
+
+    @Override
+    public boolean hasVariableArgumentList() {
+        return false;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Arrays.asList(
+                createAcceptableTypeSet(Datatype.Type.Boolean),
+                createAcceptableTypeSet(Datatype.Type.Callable)
+        );
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/IncludeBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/IncludeBuiltinFunction.java
index fb2f9fc..b3e1a9a 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/IncludeBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/IncludeBuiltinFunction.java
@@ -12,6 +12,7 @@ import com.jantuomi.tunkki.exception.types.*;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -26,13 +27,7 @@ public class IncludeBuiltinFunction extends BuiltinFunction {
 
     @Override
     public Datatype evaluate(List<Datatype> params) throws TunkkiError {
-        if (params.size() != 1) {
-            throw new FunctionArgumentTunkkiError(-1, Datatype.toString(params));
-        }
-
-        if (params.get(0).getType() != Datatype.Type.String) {
-            throw new TypeTunkkiError(-1, params.get(0).getType().toString(), "include");
-        }
+        super.evaluate(params);
 
         StringDatatype param = (StringDatatype) params.get(0);
         String filename = param.getData();
@@ -67,4 +62,16 @@ public class IncludeBuiltinFunction extends BuiltinFunction {
 
         return new VoidDatatype();
     }
+
+    @Override
+    public boolean hasVariableArgumentList() {
+        return false;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Arrays.asList(
+                createAcceptableTypeSet(Datatype.Type.String)
+        );
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/InputBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/InputBuiltinFunction.java
index 3625541..c7b53f0 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/InputBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/InputBuiltinFunction.java
@@ -7,9 +7,7 @@ import com.jantuomi.tunkki.exception.types.TunkkiError;
 import com.jantuomi.tunkki.utils.IO;
 
 import java.io.IOException;
-import java.util.Arrays;
-import java.util.List;
-import java.util.Scanner;
+import java.util.*;
 
 /**
  * Created by jan on 21.6.2016.
@@ -23,10 +21,11 @@ public class InputBuiltinFunction extends BuiltinFunction {
 
     @Override
     public Datatype evaluate(List<Datatype> params) throws TunkkiError {
-        if (params.size() > 0) {
-            Datatype param = params.get(0);
-            System.out.print(param.getData().toString());
-        }
+        super.evaluate(params);
+
+        Datatype param = params.get(0);
+        System.out.print(param.getData().toString());
+
         String in;
         try {
             in = IO.getInstance().readLine("");
@@ -36,4 +35,16 @@ public class InputBuiltinFunction extends BuiltinFunction {
             return new NadaDatatype();
         }
     }
+
+    @Override
+    public boolean hasVariableArgumentList() {
+        return false;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Collections.singletonList(
+                createAcceptableTypeSet(Datatype.Type.String)
+        );
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ListBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ListBuiltinFunction.java
index 4d82c1a..58629fc 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ListBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/ListBuiltinFunction.java
@@ -5,7 +5,9 @@ import com.jantuomi.tunkki.core.parser.datatype.ListDatatype;
 import com.jantuomi.tunkki.exception.types.TunkkiError;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by jan on 27.7.2016.
@@ -20,4 +22,14 @@ public class ListBuiltinFunction extends BuiltinFunction {
         ListDatatype data = new ListDatatype(params);
         return data;
     }
+
+    @Override
+    public boolean hasVariableArgumentList() {
+        return true;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Collections.emptyList();
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/OutputBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/OutputBuiltinFunction.java
index e4857c0..ce2aba4 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/OutputBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/OutputBuiltinFunction.java
@@ -7,6 +7,7 @@ import com.jantuomi.tunkki.utils.IO;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by jan on 21.6.2016.
@@ -24,4 +25,16 @@ public class OutputBuiltinFunction extends BuiltinFunction {
         IO.getInstance().printLine(param.getData().toString());
         return new VoidDatatype();
     }
+
+    @Override
+    public boolean hasVariableArgumentList() {
+        return false;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Arrays.asList(
+                createAcceptableTypeSet(Datatype.Type.String)
+        );
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/cast/AsBooleanBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/cast/AsBooleanBuiltinFunction.java
index 4432554..e46b88c 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/cast/AsBooleanBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/cast/AsBooleanBuiltinFunction.java
@@ -7,6 +7,7 @@ import com.jantuomi.tunkki.exception.types.TunkkiError;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by jan on 21.6.2016.
@@ -20,11 +21,9 @@ public class AsBooleanBuiltinFunction extends BuiltinFunction {
 
     @Override
     public BooleanDatatype evaluate(List<Datatype> params) throws TunkkiError {
-        if (params.size() != 1) {
-            return null;
-        }
+        super.evaluate(params);
+
         Datatype param = params.get(0);
-        boolean b;
         switch (param.getType()) {
             case Integer:
                 return new BooleanDatatype(((IntegerDatatype) param).getData() != 0);
@@ -35,4 +34,16 @@ public class AsBooleanBuiltinFunction extends BuiltinFunction {
         }
 
     }
+
+    @Override
+    public boolean hasVariableArgumentList() {
+        return false;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Arrays.asList(
+                createAcceptableTypeSet(Datatype.Type.Integer, Datatype.Type.Boolean)
+        );
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/cast/AsIntBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/cast/AsIntBuiltinFunction.java
index 773d480..6bd45ca 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/cast/AsIntBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/globals/cast/AsIntBuiltinFunction.java
@@ -7,6 +7,7 @@ import com.jantuomi.tunkki.exception.types.TunkkiError;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by jan on 21.6.2016.
@@ -20,9 +21,8 @@ public class AsIntBuiltinFunction extends BuiltinFunction {
 
     @Override
     public IntegerDatatype evaluate(List<Datatype> params) throws TunkkiError {
-        if (params.size() != 1) {
-            return null;
-        }
+        super.evaluate(params);
+
         Datatype param = params.get(0);
         int i;
         switch (param.getType()) {
@@ -45,4 +45,16 @@ public class AsIntBuiltinFunction extends BuiltinFunction {
         }
 
     }
+
+    @Override
+    public boolean hasVariableArgumentList() {
+        return false;
+    }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Arrays.asList(
+                createAcceptableTypeSet(Datatype.Type.String, Datatype.Type.Integer, Datatype.Type.Boolean, Datatype.Type.Double)
+        );
+    }
 }
diff --git a/src/main/com/jantuomi/tunkki/core/runtime/builtins/math/PowerBuiltinFunction.java b/src/main/com/jantuomi/tunkki/core/runtime/builtins/math/PowerBuiltinFunction.java
index e56a9b9..f426456 100644
--- a/src/main/com/jantuomi/tunkki/core/runtime/builtins/math/PowerBuiltinFunction.java
+++ b/src/main/com/jantuomi/tunkki/core/runtime/builtins/math/PowerBuiltinFunction.java
@@ -9,6 +9,7 @@ import com.jantuomi.tunkki.exception.types.TunkkiError;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Created by jan on 2.8.2016.
@@ -39,6 +40,11 @@ public class PowerBuiltinFunction extends BuiltinFunction {
         }
     }
 
+    @Override
+    public boolean hasVariableArgumentList() {
+        return false;
+    }
+
     private double getDoubleValue(List<Datatype> params, Datatype dt) throws TunkkiError {
         double number;
         if (dt.getType() == Datatype.Type.Integer) {
@@ -51,4 +57,12 @@ public class PowerBuiltinFunction extends BuiltinFunction {
         }
         return number;
     }
+
+    @Override
+    public List<Set<Datatype.Type>> getArgumentTypes() {
+        return Arrays.asList(
+                createAcceptableTypeSet(Datatype.Type.Integer, Datatype.Type.Double),
+                createAcceptableTypeSet(Datatype.Type.Integer, Datatype.Type.Double)
+        );
+    }
 }