Более удобная проверка аргументов функций

src/com/annimon/ownlang/lib/Arguments.java

@@ -0,0 +1,32 @@
+package com.annimon.ownlang.lib;
+
+import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
+
+public final class Arguments {
+
+    public static void check(int expected, int got) {
+        if (got != expected) throw new ArgumentsMismatchException(String.format(
+                "%d %s expected, got %d", expected, pluralize(expected), got));
+    }
+
+    public static void checkAtLeast(int expected, int got) {
+        if (got < expected) throw new ArgumentsMismatchException(String.format(
+                "At least %d %s expected, got %d", expected, pluralize(expected), got));
+    }
+
+    public static void checkOrOr(int expectedOne, int expectedTwo, int got) {
+        if (expectedOne != got && expectedTwo != got)
+            throw new ArgumentsMismatchException(String.format(
+                    "%d or %d arguments expected, got %d", expectedOne, expectedTwo, got));
+    }
+
+    public static void checkRange(int from, int to, int got) {
+        if (from > got || got > to)
+            throw new ArgumentsMismatchException(String.format(
+                    "From %d to %d arguments expected, got %d", from, to, got));
+    }
+
+    private static String pluralize(int count) {
+        return (count == 1) ? "argument" : "arguments";
+    }
+}

src/com/annimon/ownlang/lib/modules/canvas.java

@@ -88,7 +88,7 @@ public final class canvas implements Module {
     
     private static Function intConsumer4Convert(IntConsumer4 consumer) {
         return args -> {
-            if (args.length != 4) throw new ArgumentsMismatchException("Four args expected");
+            Arguments.check(4, args.length);
             consumer.accept(args[0].asInt(), args[1].asInt(), args[2].asInt(), args[3].asInt());
             return NumberValue.ZERO;
         };
@@ -181,7 +181,7 @@ public final class canvas implements Module {
         
         @Override
         public Value execute(Value... args) {
-            if (args.length != 3) throw new ArgumentsMismatchException("Three args expected");
+            Arguments.check(3, args.length);
             int x = args[1].asInt();
             int y = args[2].asInt();
             graphics.drawString(args[0].asString(), x, y);

src/com/annimon/ownlang/lib/modules/files.java

@@ -69,7 +69,7 @@ public final class files implements Module {
 
         @Override
         public Value execute(Value... args) {
-            if (args.length < 1) throw new ArgumentsMismatchException("At least one argument expected");
+            Arguments.checkAtLeast(1, args.length);
             
             final File file = new File(args[0].asString());
             try {

src/com/annimon/ownlang/lib/modules/functions/functional_combine.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
 
@@ -8,8 +7,7 @@ public final class functional_combine implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length < 1) throw new ArgumentsMismatchException("At least one arg expected");
+        Arguments.checkAtLeast(1, args.length);
-        
         Function result = null;
         for (Value arg : args) {
             if (arg.type() != Types.FUNCTION) {

src/com/annimon/ownlang/lib/modules/functions/functional_filter.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
 import java.util.ArrayList;
@@ -12,11 +11,11 @@ public final class functional_filter implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length < 2) throw new ArgumentsMismatchException("At least two args expected");
+        Arguments.check(2, args.length);
-        
         if (args[1].type() != Types.FUNCTION) {
-            throw new TypeException("Function expected in second arg");
+            throw new TypeException("Function expected in second argument");
         }
+
         final Value container = args[0];
         final Function consumer = ((FunctionValue) args[1]).getValue();
         if (container.type() == Types.ARRAY) {

src/com/annimon/ownlang/lib/modules/functions/functional_flatmap.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
 import java.util.ArrayList;
@@ -10,8 +9,7 @@ public final class functional_flatmap implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length < 2) throw new ArgumentsMismatchException("At least two arguments expected");
+        Arguments.check(2, args.length);
-        
         if (args[0].type() != Types.ARRAY) {
             throw new TypeException("Array expected in first argument");
         }

src/com/annimon/ownlang/lib/modules/functions/functional_foreach.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
 
@@ -10,7 +9,7 @@ public final class functional_foreach implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 2) throw new ArgumentsMismatchException("Two args expected");
+        Arguments.check(2, args.length);
         
         if (args[1].type() != Types.FUNCTION) {
             throw new TypeException("Function expected in second arg");

src/com/annimon/ownlang/lib/modules/functions/functional_map.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
 
@@ -10,7 +9,7 @@ public final class functional_map implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length < 2) throw new ArgumentsMismatchException("At least two args expected");
+        Arguments.checkOrOr(2, 3, args.length);
         
         final Value container = args[0];
         if (container.type() == Types.ARRAY) {

src/com/annimon/ownlang/lib/modules/functions/functional_reduce.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
 
@@ -10,10 +9,10 @@ public final class functional_reduce implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 3) throw new ArgumentsMismatchException("Three args expected");
+        Arguments.check(3, args.length);
         
         if (args[2].type() != Types.FUNCTION) {
-            throw new TypeException("Function expected in third arg");
+            throw new TypeException("Function expected in third argument");
         }
         final Value container = args[0];
         final Value identity = args[1];

src/com/annimon/ownlang/lib/modules/functions/functional_sortby.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
 import java.util.Arrays;
@@ -9,8 +8,7 @@ public final class functional_sortby implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 2) throw new ArgumentsMismatchException("Two arguments expected");
+        Arguments.check(2, args.length);
-        
         if (args[0].type() != Types.ARRAY) {
             throw new TypeException("Array expected in first argument");
         }

src/com/annimon/ownlang/lib/modules/functions/http_http.java

@@ -66,7 +66,7 @@ public final class http_http implements Function {
                 return process(url, method, args[2], (MapValue) args[3], (FunctionValue) args[4]);
                 
             default:
-                throw new ArgumentsMismatchException("Wrong number of arguments");
+                throw new ArgumentsMismatchException("From 1 to 5 arguments expected, got " + args.length);
         }
     }
     

src/com/annimon/ownlang/lib/modules/functions/http_urlencode.java

@@ -1,6 +1,6 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
+import com.annimon.ownlang.lib.Arguments;
 import com.annimon.ownlang.lib.Function;
 import com.annimon.ownlang.lib.StringValue;
 import com.annimon.ownlang.lib.Value;
@@ -11,7 +11,7 @@ public final class http_urlencode implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length == 0) throw new ArgumentsMismatchException("At least one arg expected");
+        Arguments.checkOrOr(1, 2, args.length);
         
         String charset = "UTF-8";
         if (args.length >= 2) {

src/com/annimon/ownlang/lib/modules/functions/json_decode.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 import java.util.Iterator;
 import org.json.*;
@@ -9,7 +8,7 @@ public final class json_decode implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+        Arguments.check(1, args.length);
         try {
             final String jsonRaw = args[0].asString();
             final Object root = new JSONTokener(jsonRaw).nextValue();

src/com/annimon/ownlang/lib/modules/functions/json_encode.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 import java.util.Map;
 import org.json.*;
@@ -9,7 +8,7 @@ public final class json_encode implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+        Arguments.check(1, args.length);
         try {
             final Object root = process(args[0]);
             final String jsonRaw = JSONObject.valueToString(root);

src/com/annimon/ownlang/lib/modules/functions/robot_exec.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class robot_exec implements Function {
@@ -15,7 +14,7 @@ public final class robot_exec implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length == 0) throw new ArgumentsMismatchException("At least one argument expected");
+        Arguments.checkAtLeast(1, args.length);
         
         try {
             final Process process;

src/com/annimon/ownlang/lib/modules/functions/robot_toclipboard.java

@@ -1,6 +1,6 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
+import com.annimon.ownlang.lib.Arguments;
 import com.annimon.ownlang.lib.Function;
 import com.annimon.ownlang.lib.NumberValue;
 import com.annimon.ownlang.lib.Value;
@@ -11,8 +11,7 @@ public final class robot_toclipboard implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+        Arguments.check(1, args.length);
-        
         Toolkit.getDefaultToolkit().getSystemClipboard()
                 .setContents(new StringSelection(args[0].asString()), null);
         return NumberValue.ZERO;

src/com/annimon/ownlang/lib/modules/functions/std_arrayCombine.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
 
@@ -8,7 +7,7 @@ public final class std_arrayCombine implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 2) throw new ArgumentsMismatchException("Two arguments expected");
+        Arguments.check(2, args.length);
         if (args[0].type() != Types.ARRAY) {
             throw new TypeException("Array expected in first argument");
         }

src/com/annimon/ownlang/lib/modules/functions/std_arrayKeyExists.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
 
@@ -8,7 +7,7 @@ public final class std_arrayKeyExists implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 2) throw new ArgumentsMismatchException("Two arguments expected");
+        Arguments.check(2, args.length);
         if (args[1].type() != Types.MAP) {
             throw new TypeException("Map expected in second argument");
         }

src/com/annimon/ownlang/lib/modules/functions/std_arrayKeys.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
 import java.util.ArrayList;
@@ -11,7 +10,7 @@ public final class std_arrayKeys implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+        Arguments.check(1, args.length);
         if (args[0].type() != Types.MAP) {
             throw new TypeException("Map expected in first argument");
         }

src/com/annimon/ownlang/lib/modules/functions/std_arrayValues.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
 import java.util.ArrayList;
@@ -11,7 +10,7 @@ public final class std_arrayValues implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+        Arguments.check(1, args.length);
         if (args[0].type() != Types.MAP) {
             throw new TypeException("Map expected in first argument");
         }

src/com/annimon/ownlang/lib/modules/functions/std_charat.java

@@ -1,14 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_charat implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 2) throw new ArgumentsMismatchException("Two arguments expected");
+        Arguments.check(2, args.length);
-        
         final String input = args[0].asString();
         final int index = args[1].asInt();
         

src/com/annimon/ownlang/lib/modules/functions/std_indexof.java

@@ -1,13 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_indexof implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length < 2 || args.length > 3) throw new ArgumentsMismatchException("Two or three arguments expected");
+        Arguments.checkOrOr(2, 3, args.length);
         
         final String input = args[0].asString();
         final String what = args[1].asString();

src/com/annimon/ownlang/lib/modules/functions/std_join.java

@@ -8,7 +8,7 @@ public final class std_join implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length < 1) throw new ArgumentsMismatchException("At least one argument expected");
+        Arguments.checkRange(1, 4, args.length);
         if (args[0].type() != Types.ARRAY) {
             throw new TypeException("Array expected in first argument");
         }

src/com/annimon/ownlang/lib/modules/functions/std_lastindexof.java

@@ -1,13 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_lastindexof implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length < 2 || args.length > 3) throw new ArgumentsMismatchException("Two or three arguments expected");
+        Arguments.checkOrOr(2, 3, args.length);
         
         final String input = args[0].asString();
         final String what = args[1].asString();

src/com/annimon/ownlang/lib/modules/functions/std_length.java

@@ -1,16 +1,15 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_length implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length == 0) throw new ArgumentsMismatchException("At least one arg expected");
+        Arguments.check(1, args.length);
 
         final Value val = args[0];
-        int length;
+        final int length;
         switch (val.type()) {
             case Types.ARRAY:
                 length = ((ArrayValue) val).size();

src/com/annimon/ownlang/lib/modules/functions/std_rand.java

@@ -1,5 +1,6 @@
 package com.annimon.ownlang.lib.modules.functions;
 
+import com.annimon.ownlang.lib.Arguments;
 import com.annimon.ownlang.lib.Function;
 import com.annimon.ownlang.lib.NumberValue;
 import com.annimon.ownlang.lib.Value;
@@ -12,6 +13,7 @@ public final class std_rand implements Function {
 
     @Override
     public Value execute(Value... args) {
+        Arguments.checkRange(0, 2, args.length);
         if (args.length == 0) return new NumberValue(RND.nextDouble());
 
         int from = 0;

src/com/annimon/ownlang/lib/modules/functions/std_replace.java

@@ -1,13 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_replace implements Function {
     
     @Override
     public Value execute(Value... args) {
-        if (args.length != 3) throw new ArgumentsMismatchException("Three arguments expected");
+        Arguments.check(3, args.length);
         
         final String input = args[0].asString();
         final String target = args[1].asString();

src/com/annimon/ownlang/lib/modules/functions/std_replaceall.java

@@ -1,13 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_replaceall implements Function {
     
     @Override
     public Value execute(Value... args) {
-        if (args.length != 3) throw new ArgumentsMismatchException("Three arguments expected");
+        Arguments.check(3, args.length);
         
         final String input = args[0].asString();
         final String regex = args[1].asString();

src/com/annimon/ownlang/lib/modules/functions/std_replacefirst.java

@@ -1,13 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_replacefirst implements Function {
     
     @Override
     public Value execute(Value... args) {
-        if (args.length != 3) throw new ArgumentsMismatchException("Three arguments expected");
+        Arguments.check(3, args.length);
         
         final String input = args[0].asString();
         final String regex = args[1].asString();

src/com/annimon/ownlang/lib/modules/functions/std_sleep.java

@@ -1,6 +1,6 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
+import com.annimon.ownlang.lib.Arguments;
 import com.annimon.ownlang.lib.Function;
 import com.annimon.ownlang.lib.NumberValue;
 import com.annimon.ownlang.lib.Value;
@@ -9,7 +9,7 @@ public final class std_sleep implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+        Arguments.check(1, args.length);
         
         try {
             Thread.sleep((long) args[0].asNumber());

src/com/annimon/ownlang/lib/modules/functions/std_sort.java

@@ -9,7 +9,7 @@ public final class std_sort implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length < 1) throw new ArgumentsMismatchException("At least one argument expected");
+        Arguments.checkAtLeast(1, args.length);
         if (args[0].type() != Types.ARRAY) {
             throw new TypeException("Array expected in first argument");
         }

src/com/annimon/ownlang/lib/modules/functions/std_split.java

@@ -1,13 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_split implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length < 2 || args.length > 3) throw new ArgumentsMismatchException("Two or three arguments expected");
+        Arguments.checkOrOr(2, 3, args.length);
 
         final String input = args[0].asString();
         final String regex = args[1].asString();

src/com/annimon/ownlang/lib/modules/functions/std_sprintf.java

@@ -1,13 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_sprintf implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length < 1) throw new ArgumentsMismatchException("At least one argument expected");
+        Arguments.checkAtLeast(1, args.length);
         
         final String format = args[0].asString();
         final Object[] values = new Object[args.length - 1];

src/com/annimon/ownlang/lib/modules/functions/std_substring.java

@@ -1,13 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_substring implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length < 2 || args.length > 3) throw new ArgumentsMismatchException("Two or three arguments expected");
+        Arguments.checkOrOr(2, 3, args.length);
         
         final String input = args[0].asString();
         final int startIndex = args[1].asInt();

src/com/annimon/ownlang/lib/modules/functions/std_thread.java

@@ -1,16 +1,13 @@
 package com.annimon.ownlang.lib.modules.functions;
 
 import com.annimon.ownlang.Console;
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_thread implements Function {
 
     @Override
     public Value execute(Value... args) {
-        // Создаём новый поток и передаём параметры, если есть.
+        Arguments.checkAtLeast(1, args.length);
-        // Функция может передаваться как напрямую, так и по имени
-        if (args.length == 0) throw new ArgumentsMismatchException("At least one arg expected");
         
         Function body;
         if (args[0].type() == Types.FUNCTION) {

src/com/annimon/ownlang/lib/modules/functions/std_tochar.java

@@ -1,14 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_tochar implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+        Arguments.check(1, args.length);
-        
         return new StringValue(String.valueOf((char) args[0].asInt()));
     }
 }

src/com/annimon/ownlang/lib/modules/functions/std_tolowercase.java

@@ -1,14 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_tolowercase implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+        Arguments.check(1, args.length);
-        
         return new StringValue(args[0].asString().toLowerCase());
     }
 }

src/com/annimon/ownlang/lib/modules/functions/std_touppercase.java

@@ -1,14 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_touppercase implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+        Arguments.check(1, args.length);
-        
         return new StringValue(args[0].asString().toUpperCase());
     }
 }

src/com/annimon/ownlang/lib/modules/functions/std_trim.java

@@ -1,14 +1,12 @@
 package com.annimon.ownlang.lib.modules.functions;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 
 public final class std_trim implements Function {
 
     @Override
     public Value execute(Value... args) {
-        if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+        Arguments.check(1, args.length);
-        
         return new StringValue(args[0].asString().trim());
     }
 }

src/com/annimon/ownlang/lib/modules/math.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 import java.util.function.DoubleBinaryOperator;
 import java.util.function.DoubleFunction;
@@ -58,14 +57,14 @@ public final class math implements Module {
     
     private static Function functionConvert(DoubleUnaryOperator op) {
         return args -> {
-            if (args.length != 1) throw new ArgumentsMismatchException("One arg expected");
+            Arguments.check(1, args.length);
             return doubleToNumber.apply(op.applyAsDouble(args[0].asNumber()));
         };
     }
     
     private static Function biFunctionConvert(DoubleBinaryOperator op) {
         return args -> {
-            if (args.length != 2) throw new ArgumentsMismatchException("Two args expected");
+            Arguments.check(2, args.length);
             return doubleToNumber.apply(op.applyAsDouble(args[0].asNumber(), args[1].asNumber()));
         };
     }

src/com/annimon/ownlang/lib/modules/ounit.java

@@ -28,6 +28,7 @@ public final class ounit implements Module {
     private static class assertEquals implements Function {
         @Override
         public Value execute(Value... args) {
+            Arguments.check(2, args.length);
             if (args[0].equals(args[1])) return NumberValue.ONE;
             throw new OUnitAssertionException("Values are not equals: "
                     + "1: " + args[0] + ", 2: " + args[1]);
@@ -37,6 +38,7 @@ public final class ounit implements Module {
     private static class assertNotEquals implements Function {
         @Override
         public Value execute(Value... args) {
+            Arguments.check(2, args.length);
             if (!args[0].equals(args[1])) return NumberValue.ONE;
             throw new OUnitAssertionException("Values are equals: " + args[0]);
         }
@@ -45,6 +47,7 @@ public final class ounit implements Module {
     private static class assertSameType implements Function {
         @Override
         public Value execute(Value... args) {
+            Arguments.check(2, args.length);
             if (args[0].type() == args[1].type()) return NumberValue.ONE;
             throw new OUnitAssertionException("Types mismatch. "
                     + "1: " + Types.typeToString(args[0].type())
@@ -55,6 +58,7 @@ public final class ounit implements Module {
     private static class assertTrue implements Function {
         @Override
         public Value execute(Value... args) {
+            Arguments.check(1, args.length);
             if (args[0].asInt() != 0) return NumberValue.ONE;
             throw new OUnitAssertionException("Expected true, but found false.");
         }
@@ -63,6 +67,7 @@ public final class ounit implements Module {
     private static class assertFalse implements Function {
         @Override
         public Value execute(Value... args) {
+            Arguments.check(1, args.length);
             if (args[0].asInt() == 0) return NumberValue.ONE;
             throw new OUnitAssertionException("Expected false, but found true.");
         }

src/com/annimon/ownlang/lib/modules/robot.java

@@ -1,6 +1,5 @@
 package com.annimon.ownlang.lib.modules;
 
-import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 import com.annimon.ownlang.lib.*;
 import com.annimon.ownlang.lib.modules.functions.robot_exec;
 import com.annimon.ownlang.lib.modules.functions.robot_fromclipboard;
@@ -43,14 +42,14 @@ public final class robot implements Module {
         Functions.set("mouseRelease", convertFunction(awtRobot::mouseRelease));
         Functions.set("mouseWheel", convertFunction(awtRobot::mouseWheel));
         Functions.set("mouseMove", (args) -> {
-            if (args.length != 2) throw new ArgumentsMismatchException("Two arguments expected");
+            Arguments.check(2, args.length);
             try {
                 awtRobot.mouseMove(args[0].asInt(), args[1].asInt());
             } catch (IllegalArgumentException iae) { }
             return NumberValue.ZERO;
         });
         Functions.set("typeText", (args) -> {
-            if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+            Arguments.check(1, args.length);
             try {
                 typeText(args[0].asString());
             } catch (IllegalArgumentException iae) { }
@@ -87,7 +86,7 @@ public final class robot implements Module {
     
     private static Function convertFunction(RobotIntConsumer consumer) {
         return args -> {
-            if (args.length != 1) throw new ArgumentsMismatchException("One argument expected");
+            Arguments.check(1, args.length);
             try {
                 consumer.accept(args[0].asInt());
             } catch (IllegalArgumentException iae) { }