Add basic user defined function support

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/Parser.java

@@ -21,8 +21,8 @@ import com.dfsek.terra.addons.terrascript.parser.lang.constants.BooleanConstant;
 import com.dfsek.terra.addons.terrascript.parser.lang.constants.ConstantExpression;
 import com.dfsek.terra.addons.terrascript.parser.lang.constants.NumericConstant;
 import com.dfsek.terra.addons.terrascript.parser.lang.constants.StringConstant;
-import com.dfsek.terra.addons.terrascript.parser.lang.functions.Function;
 import com.dfsek.terra.addons.terrascript.parser.lang.functions.FunctionBuilder;
+import com.dfsek.terra.addons.terrascript.parser.lang.functions.UserDefinedFunctionBuilder;
 import com.dfsek.terra.addons.terrascript.parser.lang.keywords.flow.BreakKeyword;
 import com.dfsek.terra.addons.terrascript.parser.lang.keywords.flow.ContinueKeyword;
 import com.dfsek.terra.addons.terrascript.parser.lang.keywords.flow.FailKeyword;
@@ -77,17 +77,17 @@ public class Parser {
      * @throws ParseException If parsing fails.
      */
     public Executable parse(ScopeBuilder scopeBuilder) {
-        return new Executable(parseBlock(new Tokenizer(source), scopeBuilder), scopeBuilder);
+        return new Executable(parseBlock(new Tokenizer(source), scopeBuilder, ReturnType.VOID), scopeBuilder);
     }
     
     private WhileKeyword parseWhileLoop(Tokenizer tokenizer, ScopeBuilder scopeBuilder) {
         SourcePosition start = tokenizer.consume().getPosition();
         ParserUtil.ensureType(tokenizer.consume(), Token.Type.GROUP_BEGIN);
-        scopeBuilder = scopeBuilder.subInLoop();
+        scopeBuilder = scopeBuilder.innerLoopScope();
         Expression<?> condition = parseExpression(tokenizer, true, scopeBuilder);
         ParserUtil.ensureReturnType(condition, Expression.ReturnType.BOOLEAN);
         ParserUtil.ensureType(tokenizer.consume(), Token.Type.GROUP_END);
-        return new WhileKeyword(parseStatementBlock(tokenizer, scopeBuilder), (Expression<Boolean>) condition, start); // While loop
+        return new WhileKeyword(parseStatementBlock(tokenizer, scopeBuilder, ReturnType.VOID), (Expression<Boolean>) condition, start); // While loop
     }
     
     private IfKeyword parseIfStatement(Tokenizer tokenizer, ScopeBuilder scopeBuilder) {
@@ -99,7 +99,7 @@ public class Parser {
         ParserUtil.ensureType(tokenizer.consume(), Token.Type.GROUP_END);
         
         Block elseBlock = null;
-        Block statement = parseStatementBlock(tokenizer, scopeBuilder);
+        Block statement = parseStatementBlock(tokenizer, scopeBuilder, ReturnType.VOID);
         
         List<Pair<Expression<Boolean>, Block>> elseIf = new ArrayList<>();
         
@@ -109,9 +109,9 @@ public class Parser {
                 tokenizer.consume(); // Consume if.
                 Expression<?> elseCondition = parseExpression(tokenizer, true, scopeBuilder);
                 ParserUtil.ensureReturnType(elseCondition, Expression.ReturnType.BOOLEAN);
-                elseIf.add(Pair.of((Expression<Boolean>) elseCondition, parseStatementBlock(tokenizer, scopeBuilder)));
+                elseIf.add(Pair.of((Expression<Boolean>) elseCondition, parseStatementBlock(tokenizer, scopeBuilder, ReturnType.VOID)));
             } else {
-                elseBlock = parseStatementBlock(tokenizer, scopeBuilder);
+                elseBlock = parseStatementBlock(tokenizer, scopeBuilder, ReturnType.VOID);
                 break; // Else must be last.
             }
         }
@@ -119,29 +119,29 @@ public class Parser {
         return new IfKeyword(statement, (Expression<Boolean>) condition, elseIf, elseBlock, start); // If statement
     }
     
-    private Block parseStatementBlock(Tokenizer tokenizer, ScopeBuilder scopeBuilder) {
+    private Block parseStatementBlock(Tokenizer tokenizer, ScopeBuilder scopeBuilder, ReturnType blockReturnType) {
         if(tokenizer.current().isType(Token.Type.BLOCK_BEGIN)) {
             ParserUtil.ensureType(tokenizer.consume(), Token.Type.BLOCK_BEGIN);
-            Block block = parseBlock(tokenizer, scopeBuilder);
+            Block block = parseBlock(tokenizer, scopeBuilder, blockReturnType);
             ParserUtil.ensureType(tokenizer.consume(), Token.Type.BLOCK_END);
             return block;
         } else {
             SourcePosition position = tokenizer.current().getPosition();
-            return new Block(Collections.singletonList(parseStatement(tokenizer, scopeBuilder)), position);
+            return new Block(Collections.singletonList(parseStatement(tokenizer, scopeBuilder)), position, blockReturnType);
         }
     }
     
     private ForKeyword parseForLoop(Tokenizer tokenizer, ScopeBuilder scopeBuilder) {
         SourcePosition start = tokenizer.consume().getPosition();
         ParserUtil.ensureType(tokenizer.consume(), Token.Type.GROUP_BEGIN);
-        scopeBuilder = scopeBuilder.subInLoop(); // new scope
+        scopeBuilder = scopeBuilder.innerLoopScope(); // new scope
         Token f = tokenizer.current();
-        ParserUtil.ensureType(f, Token.Type.NUMBER_VARIABLE, Token.Type.STRING_VARIABLE, Token.Type.BOOLEAN_VARIABLE, Token.Type.IDENTIFIER);
+        ParserUtil.ensureType(f, Token.Type.TYPE_NUMBER, Token.Type.TYPE_STRING, Token.Type.TYPE_BOOLEAN, Token.Type.IDENTIFIER);
         Expression<?> initializer;
         if(f.isVariableDeclaration()) {
-            VariableAssignmentNode<?> forVar = parseVariableDeclaration(tokenizer, scopeBuilder);
+            Expression<?> forVar = parseDeclaration(tokenizer, scopeBuilder);
             Token name = tokenizer.current();
-            if(scopeBuilder.containsKey(name.getContent()) || scopeBuilder.contains(name.getContent()))
+            if(scopeBuilder.containsFunction(name.getContent()) || scopeBuilder.contains(name.getContent()))
                 throw new ParseException(name.getContent() + " is already defined in this scope", name.getPosition());
             initializer = forVar;
         } else initializer = parseExpression(tokenizer, true, scopeBuilder);
@@ -158,7 +158,7 @@ public class Parser {
         
         ParserUtil.ensureType(tokenizer.consume(), Token.Type.GROUP_END);
         
-        return new ForKeyword(parseStatementBlock(tokenizer, scopeBuilder), initializer, (Expression<Boolean>) conditional, incrementer,
+        return new ForKeyword(parseStatementBlock(tokenizer, scopeBuilder, ReturnType.VOID), initializer, (Expression<Boolean>) conditional, incrementer,
                               start);
     }
     
@@ -183,7 +183,7 @@ public class Parser {
         } else if(id.isType(Token.Type.GROUP_BEGIN)) { // Parse grouped expression
             expression = parseExpressionGroup(tokenizer, scopeBuilder);
         } else {
-            if(scopeBuilder.containsKey(id.getContent()))
+            if(scopeBuilder.containsFunction(id.getContent()))
                 expression = parseFunctionInvocation(tokenizer, false, scopeBuilder);
             else if(scopeBuilder.contains(id.getContent())) {
                 ParserUtil.ensureType(tokenizer.consume(), Token.Type.IDENTIFIER);
@@ -196,7 +196,7 @@ public class Parser {
                     default -> throw new ParseException("Illegal type for variable reference: " + varType, id.getPosition());
                 };
                 
-            } else throw new ParseException("Unexpected token \" " + id.getContent() + "\"", id.getPosition());
+            } else throw new ParseException("Unexpected token \"" + id.getContent() + "\"", id.getPosition());
         }
         
         if(booleanInverted) { // Invert operation if boolean not detected
@@ -292,48 +292,115 @@ public class Parser {
         }
     }
     
-    private VariableAssignmentNode<?> parseVariableDeclaration(Tokenizer tokenizer, ScopeBuilder scopeBuilder) {
+    private Expression<?> parseDeclaration(Tokenizer tokenizer, ScopeBuilder scopeBuilder) {
         Token type = tokenizer.consume();
-        ParserUtil.ensureType(type, Token.Type.STRING_VARIABLE, Token.Type.BOOLEAN_VARIABLE, Token.Type.NUMBER_VARIABLE);
         
-        Expression.ReturnType returnType = ParserUtil.getVariableReturnType(type);
-        
-        ParserUtil.checkVarType(type, returnType); // Check for type mismatch
         Token identifier = tokenizer.consume();
         ParserUtil.ensureType(identifier, Token.Type.IDENTIFIER);
-        if(scopeBuilder.containsKey(identifier.getContent()) || scopeBuilder.contains(identifier.getContent()))
+        
+        Token declarationType = tokenizer.consume();
+        ParserUtil.ensureType(declarationType, Token.Type.ASSIGNMENT, Token.Type.GROUP_BEGIN);
+        
+        return switch(declarationType.getType()) {
+            case ASSIGNMENT -> parseVariableDeclaration(tokenizer, scopeBuilder, type, identifier);
+            case GROUP_BEGIN -> parseFunctionDeclaration(tokenizer, scopeBuilder, type, identifier);
+            default -> throw new ParseException("Illegal type for declaration: " + type, declarationType.getPosition());
+        };
+    }
+    
+    
+    private Expression<?> parseVariableDeclaration(Tokenizer tokenizer, ScopeBuilder scopeBuilder, Token type, Token identifier) {
+        ParserUtil.ensureType(type, Token.Type.TYPE_STRING, Token.Type.TYPE_BOOLEAN, Token.Type.TYPE_NUMBER);
+        
+        if(scopeBuilder.contains(identifier.getContent()))
             throw new ParseException(identifier.getContent() + " is already defined in this scope", identifier.getPosition());
-        ParserUtil.ensureType(tokenizer.consume(), Token.Type.ASSIGNMENT);
         
         Expression<?> value = parseExpression(tokenizer, true, scopeBuilder);
-        ParserUtil.ensureReturnType(value, returnType);
+        ParserUtil.ensureReturnType(value, ParserUtil.getVariableReturnType(type));
-
+        
-        String id = identifier.getContent();
+        String variableName = identifier.getContent();
-
         return switch(value.returnType()) {
-            case NUMBER -> new NumAssignmentNode((Expression<Number>) value, identifier.getPosition(), scopeBuilder.num(id));
+            case NUMBER -> new NumAssignmentNode((Expression<Number>) value, identifier.getPosition(), scopeBuilder.declareNum(variableName));
-            case STRING -> new StrAssignmentNode((Expression<String>) value, identifier.getPosition(), scopeBuilder.str(id));
+            case STRING -> new StrAssignmentNode((Expression<String>) value, identifier.getPosition(), scopeBuilder.declareStr(variableName));
-            case BOOLEAN -> new BoolAssignmentNode((Expression<Boolean>) value, identifier.getPosition(), scopeBuilder.bool(id));
+            case BOOLEAN -> new BoolAssignmentNode((Expression<Boolean>) value, identifier.getPosition(), scopeBuilder.declareBool(variableName));
             default -> throw new ParseException("Illegal type for variable declaration: " + type, value.getPosition());
         };
     }
     
-    private Block parseBlock(Tokenizer tokenizer, ScopeBuilder scopeBuilder) {
+    private Expression<?> parseFunctionDeclaration(Tokenizer tokenizer, ScopeBuilder scopeBuilder, Token type, Token identifier) {
+        ParserUtil.ensureType(type, Token.Type.TYPE_STRING, Token.Type.TYPE_BOOLEAN, Token.Type.TYPE_NUMBER, Token.Type.TYPE_VOID);
+        
+        if(scopeBuilder.contains(identifier.getContent()))
+            throw new ParseException(identifier.getContent() + " is already defined in this scope", identifier.getPosition());
+        
+        ReturnType returnType = ParserUtil.getVariableReturnType(type);
+        
+        ScopeBuilder functionBodyScope = scopeBuilder.functionScope();
+        
+        // Declare argument names into function body scope
+        List<Pair<Integer, ReturnType>> argumentInfo = getFunctionArgumentsDeclaration(tokenizer).stream().map(arg -> Pair.of(switch(arg.getRight()) {
+            case NUMBER -> functionBodyScope.declareNum(arg.getLeft());
+            case BOOLEAN -> functionBodyScope.declareBool(arg.getLeft());
+            case STRING -> functionBodyScope.declareStr(arg.getLeft());
+            default -> throw new IllegalArgumentException("Unsupported argument type: " + arg.getRight());
+        }, arg.getRight())).toList();
+        
+        Block body = parseStatementBlock(tokenizer, functionBodyScope, returnType);
+        
+        FunctionBuilder<?> functionBuilder = new UserDefinedFunctionBuilder<>(returnType, argumentInfo, body, functionBodyScope);
+        
+        scopeBuilder.registerFunction(identifier.getContent(), functionBuilder);
+        return Expression.NOOP;
+    }
+    
+    private List<Pair<String, ReturnType>> getFunctionArgumentsDeclaration(Tokenizer tokenizer) {
+        List<Pair<String, ReturnType>> arguments = new ArrayList<>();
+        while (tokenizer.current().getType() != Token.Type.GROUP_END) {
+            // Parse argument type
+            Token typeToken = tokenizer.consume();
+            ParserUtil.ensureType(typeToken, Token.Type.TYPE_BOOLEAN, Token.Type.TYPE_STRING, Token.Type.TYPE_NUMBER);
+            ReturnType argType = ParserUtil.getVariableReturnType(typeToken);
+            
+            // Parse argument name
+            Token identifierToken = tokenizer.consume();
+            ParserUtil.ensureType(identifierToken, Token.Type.IDENTIFIER);
+            String argName = identifierToken.getContent();
+            
+            arguments.add(Pair.of(argName, argType));
+            
+            // Consume separator if present, trailing separators are allowed
+            if (tokenizer.current().isType(Token.Type.SEPARATOR)) tokenizer.consume();
+        }
+        ParserUtil.ensureType(tokenizer.consume(), Token.Type.GROUP_END);
+        return arguments;
+    }
+    
+    private Block parseBlock(Tokenizer tokenizer, ScopeBuilder scopeBuilder, ReturnType blockReturnType) {
         List<Expression<?>> expressions = new ArrayList<>();
-        scopeBuilder = scopeBuilder.sub();
+        scopeBuilder = scopeBuilder.innerScope();
         SourcePosition startPosition = tokenizer.current().getPosition();
         
+        boolean hasReturn = false;
+        
         // Parse each statement
         while(tokenizer.hasNext()) {
             Token token = tokenizer.current();
             if(token.isType(Token.Type.BLOCK_END)) break; // Stop parsing at block end.
             Expression<?> expression = parseStatement(tokenizer, scopeBuilder);
-            if(expression != Function.NULL) {
+            if(expression != Expression.NOOP) {
                 expressions.add(expression);
             }
+            if(expression instanceof ReturnKeyword returnKeyword) {
+                hasReturn = true;
+                if (returnKeyword.dataReturnType() != blockReturnType)
+                    throw new ParseException("Invalid return type, expected " + blockReturnType + ", found " + returnKeyword.dataReturnType(), expression.getPosition());
+            }
         }
         
-        return new Block(expressions, startPosition);
+        if (blockReturnType != ReturnType.VOID && !hasReturn)
+            throw new ParseException("Block does not contain a return statement, must return type " + blockReturnType, startPosition);
+        
+        return new Block(expressions, startPosition, blockReturnType);
     }
     
     private Expression<?> parseStatement(Tokenizer tokenizer, ScopeBuilder scopeBuilder) {
@@ -341,10 +408,10 @@ public class Parser {
         
         // Include BREAK and CONTINUE as valid token types if scope is within a loop
         if(scopeBuilder.isInLoop()) ParserUtil.ensureType(token, Token.Type.IDENTIFIER, Token.Type.IF_STATEMENT, Token.Type.WHILE_LOOP, Token.Type.FOR_LOOP,
-                                                          Token.Type.NUMBER_VARIABLE, Token.Type.STRING_VARIABLE, Token.Type.BOOLEAN_VARIABLE,
+                                                          Token.Type.TYPE_NUMBER, Token.Type.TYPE_STRING, Token.Type.TYPE_BOOLEAN, Token.Type.TYPE_VOID,
                                                           Token.Type.RETURN, Token.Type.BREAK, Token.Type.CONTINUE, Token.Type.FAIL);
         else ParserUtil.ensureType(token, Token.Type.IDENTIFIER, Token.Type.IF_STATEMENT, Token.Type.WHILE_LOOP, Token.Type.FOR_LOOP,
-                                   Token.Type.NUMBER_VARIABLE, Token.Type.STRING_VARIABLE, Token.Type.BOOLEAN_VARIABLE, Token.Type.RETURN,
+                                   Token.Type.TYPE_NUMBER, Token.Type.TYPE_STRING, Token.Type.TYPE_BOOLEAN, Token.Type.TYPE_VOID, Token.Type.RETURN,
                                    Token.Type.FAIL);
         
         Expression<?> expression = switch(token.getType()) {
@@ -355,17 +422,27 @@ public class Parser {
                 if(scopeBuilder.contains(token.getContent())) yield parseAssignment(tokenizer, scopeBuilder); // Assume variable assignment
                 else yield parseFunctionInvocation(tokenizer, true, scopeBuilder);
             }
-            case NUMBER_VARIABLE, STRING_VARIABLE, BOOLEAN_VARIABLE -> parseVariableDeclaration(tokenizer, scopeBuilder);
+            case TYPE_NUMBER, TYPE_STRING, TYPE_BOOLEAN, TYPE_VOID -> parseDeclaration(tokenizer, scopeBuilder);
-            case RETURN -> new ReturnKeyword(tokenizer.consume().getPosition());
+            case RETURN -> parseReturn(tokenizer, scopeBuilder);
             case BREAK -> new BreakKeyword(tokenizer.consume().getPosition());
             case CONTINUE -> new ContinueKeyword(tokenizer.consume().getPosition());
             case FAIL -> new FailKeyword(tokenizer.consume().getPosition());
             default -> throw new UnsupportedOperationException("Unexpected token " + token.getType() + ": " + token.getPosition());
         };
-        if(!token.isControlStructure()) ParserUtil.ensureType(tokenizer.consume(), Token.Type.STATEMENT_END);
+        if(!token.isControlStructure() && expression != Expression.NOOP) ParserUtil.ensureType(tokenizer.consume(), Token.Type.STATEMENT_END);
         return expression;
     }
     
+    private ReturnKeyword parseReturn(Tokenizer tokenizer, ScopeBuilder scopeBuilder) {
+        Token returnToken = tokenizer.consume();
+        ParserUtil.ensureType(returnToken, Token.Type.RETURN);
+        Expression<?> data = null;
+        if (!tokenizer.current().isType(Token.Type.STATEMENT_END)) {
+            data = parseExpression(tokenizer, true, scopeBuilder);
+        }
+        return new ReturnKeyword(data, returnToken.getPosition());
+    }
+    
     private VariableAssignmentNode<?> parseAssignment(Tokenizer tokenizer, ScopeBuilder scopeBuilder) {
         Token identifier = tokenizer.consume();
         
@@ -389,12 +466,12 @@ public class Parser {
         };
     }
     
-    private Function<?> parseFunctionInvocation(Tokenizer tokenizer, boolean fullStatement, ScopeBuilder scopeBuilder) {
+    private Expression<?> parseFunctionInvocation(Tokenizer tokenizer, boolean fullStatement, ScopeBuilder scopeBuilder) {
         Token identifier = tokenizer.consume();
         ParserUtil.ensureType(identifier, Token.Type.IDENTIFIER); // First token must be identifier
         
-        if(!scopeBuilder.containsKey(identifier.getContent()))
+        if(!scopeBuilder.containsFunction(identifier.getContent()))
-            throw new ParseException("No such function \"" + identifier.getContent() + "\"", identifier.getPosition());
+            throw new ParseException("Function \"" + identifier.getContent() + "\" is not defined in this scope", identifier.getPosition());
         
         ParserUtil.ensureType(tokenizer.consume(), Token.Type.GROUP_BEGIN); // Second is body begin
         
@@ -405,11 +482,11 @@ public class Parser {
         if(fullStatement) ParserUtil.ensureType(tokenizer.current(), Token.Type.STATEMENT_END);
         
         if(ignoredFunctions.contains(identifier.getContent())) {
-            return Function.NULL;
+            return Expression.NOOP;
         }
         
-        if(scopeBuilder.containsKey(identifier.getContent())) {
+        if(scopeBuilder.containsFunction(identifier.getContent())) {
-            FunctionBuilder<?> builder = scopeBuilder.get(identifier.getContent());
+            FunctionBuilder<?> builder = scopeBuilder.getFunction(identifier.getContent());
             
             if(builder.argNumber() != -1 && args.size() != builder.argNumber())
                 throw new ParseException("Expected " + builder.argNumber() + " arguments, found " + args.size(), identifier.getPosition());

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/ParserUtil.java

@@ -78,9 +78,9 @@ public class ParserUtil {
     }
     
     public static void checkVarType(Token token, Expression.ReturnType returnType) {
-        if(returnType.equals(Expression.ReturnType.STRING) && token.getType().equals(Token.Type.STRING_VARIABLE)) return;
+        if(returnType.equals(Expression.ReturnType.STRING) && token.getType().equals(Token.Type.TYPE_STRING)) return;
-        if(returnType.equals(Expression.ReturnType.NUMBER) && token.getType().equals(Token.Type.NUMBER_VARIABLE)) return;
+        if(returnType.equals(Expression.ReturnType.NUMBER) && token.getType().equals(Token.Type.TYPE_NUMBER)) return;
-        if(returnType.equals(Expression.ReturnType.BOOLEAN) && token.getType().equals(Token.Type.BOOLEAN_VARIABLE)) return;
+        if(returnType.equals(Expression.ReturnType.BOOLEAN) && token.getType().equals(Token.Type.TYPE_BOOLEAN)) return;
         throw new ParseException("Type mismatch, cannot convert from " + returnType + " to " + token.getType(), token.getPosition());
     }
     
@@ -98,9 +98,10 @@ public class ParserUtil {
     
     public static Expression.ReturnType getVariableReturnType(Token varToken) {
         return switch(varToken.getType()) {
-            case NUMBER_VARIABLE -> Expression.ReturnType.NUMBER;
+            case TYPE_NUMBER -> Expression.ReturnType.NUMBER;
-            case STRING_VARIABLE -> Expression.ReturnType.STRING;
+            case TYPE_STRING -> Expression.ReturnType.STRING;
-            case BOOLEAN_VARIABLE -> Expression.ReturnType.BOOLEAN;
+            case TYPE_BOOLEAN -> Expression.ReturnType.BOOLEAN;
+            case TYPE_VOID -> Expression.ReturnType.VOID;
             default -> throw new ParseException("Unexpected token " + varToken.getType() + "; expected variable declaration",
                                                 varToken.getPosition());
         };

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/Block.java

@@ -9,33 +9,36 @@ package com.dfsek.terra.addons.terrascript.parser.lang;
 
 import java.util.List;
 
-import com.dfsek.terra.addons.terrascript.parser.lang.Block.ReturnInfo;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationInfo;
+import com.dfsek.terra.addons.terrascript.parser.lang.functions.Function;
 import com.dfsek.terra.addons.terrascript.tokenizer.SourcePosition;
 
 
-public class Block implements Expression<ReturnInfo<?>> {
+public class Block implements Expression<EvaluationInfo<?>> {
     private final List<Expression<?>> items;
     private final SourcePosition position;
+    private final ReturnType returnType;
     
-    public Block(List<Expression<?>> items, SourcePosition position) {
+    public Block(List<Expression<?>> items, SourcePosition position, ReturnType returnType) {
         this.items = items;
         this.position = position;
+        this.returnType = returnType;
     }
     
     @Override
     public ReturnType returnType() {
-        return ReturnType.VOID;
+        return returnType;
     }
     
     @Override
-    public ReturnInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
+    public EvaluationInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
         for(Expression<?> item : items) {
             Object result = item.evaluate(implementationArguments, scope);
-            if(result instanceof ReturnInfo<?> level) {
+            if(result instanceof EvaluationInfo<?> evalInfo) {
-                if(!level.getLevel().equals(ReturnLevel.NONE)) return level;
+                if(!evalInfo.level().equals(EvaluationLevel.NONE)) return evalInfo;
             }
         }
-        return new ReturnInfo<>(ReturnLevel.NONE, null);
+        return new EvaluationInfo<>(EvaluationLevel.NONE, Expression.NOOP);
     }
     
     @Override
@@ -43,7 +46,7 @@ public class Block implements Expression<ReturnInfo<?>> {
         return position;
     }
     
-    public enum ReturnLevel {
+    public enum EvaluationLevel {
         NONE(false),
         BREAK(false),
         CONTINUE(false),
@@ -52,7 +55,7 @@ public class Block implements Expression<ReturnInfo<?>> {
         
         private final boolean returnFast;
         
-        ReturnLevel(boolean returnFast) {
+        EvaluationLevel(boolean returnFast) {
             this.returnFast = returnFast;
         }
         
@@ -62,21 +65,6 @@ public class Block implements Expression<ReturnInfo<?>> {
     }
     
     
-    public static class ReturnInfo<T> {
+    public record EvaluationInfo<T extends Expression<?>>(EvaluationLevel level, T data) {
-        private final ReturnLevel level;
-        private final T data;
-        
-        public ReturnInfo(ReturnLevel level, T data) {
-            this.level = level;
-            this.data = data;
-        }
-        
-        public ReturnLevel getLevel() {
-            return level;
-        }
-        
-        public T getData() {
-            return data;
-        }
     }
 }

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/Executable.java

@@ -14,6 +14,6 @@ public class Executable {
     }
 
     public boolean execute(ImplementationArguments arguments) {
-        return script.evaluate(arguments, scope.get()).getLevel() != Block.ReturnLevel.FAIL;
+        return script.evaluate(arguments, scope.get()).level() != Block.EvaluationLevel.FAIL;
     }
 }

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/Expression.java

@@ -25,6 +25,23 @@ public interface Expression<T> {
     
     SourcePosition getPosition();
     
+    Expression<Void> NOOP = new Expression<>() {
+        @Override
+        public ReturnType returnType() {
+            return ReturnType.VOID;
+        }
+        
+        @Override
+        public Void evaluate(ImplementationArguments implementationArguments, Scope scope) {
+            return null;
+        }
+        
+        @Override
+        public SourcePosition getPosition() {
+            return null;
+        }
+    };
+    
     enum ReturnType {
         NUMBER(true),
         STRING(true),

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/Scope.java

@@ -1,7 +1,6 @@
 package com.dfsek.terra.addons.terrascript.parser.lang;
 
 
-import com.dfsek.terra.addons.terrascript.parser.Parser;
 import com.dfsek.terra.addons.terrascript.parser.lang.functions.Function;
 import com.dfsek.terra.addons.terrascript.parser.lang.functions.FunctionBuilder;
 
@@ -73,26 +72,33 @@ public class Scope {
             this.inLoop = inLoop;
         }
         
+        private ScopeBuilder(Map<String, FunctionBuilder<? extends Function<?>>> functions) {
+            this.functions = new HashMap<>(functions);
+            this.indices = new HashMap<>();
+        }
+        
         public Scope build() {
             return new Scope(numSize, boolSize, strSize);
         }
         
-        public ScopeBuilder sub() {
+        public ScopeBuilder innerScope() {
             return new ScopeBuilder(this, inLoop);
         }
         
-        public ScopeBuilder subInLoop() { return new ScopeBuilder(this, true); }
+        public ScopeBuilder innerLoopScope() { return new ScopeBuilder(this, true); }
+        
+        public ScopeBuilder functionScope() { return new ScopeBuilder(functions); }
         
         public ScopeBuilder registerFunction(String name, FunctionBuilder<? extends Function<?>> functionBuilder) {
             functions.put(name, functionBuilder);
             return this;
         }
         
-        public boolean containsKey(String functionName) {
+        public boolean containsFunction(String functionName) {
             return functions.containsKey(functionName);
         }
         
-        public FunctionBuilder<?> get(String functionName) {
+        public FunctionBuilder<?> getFunction(String functionName) {
             return functions.get(functionName);
         }
         
@@ -106,8 +112,8 @@ public class Scope {
         public boolean isInLoop() {
             return inLoop;
         }
-
+        
-        public int num(String id) {
+        public int declareNum(String id) {
             int num = numSize;
             indices.put(check(id), Pair.of(num, ReturnType.NUMBER));
             numSize++;
@@ -115,7 +121,7 @@ public class Scope {
             return num;
         }
         
-        public int str(String id) {
+        public int declareStr(String id) {
             int str = strSize;
             indices.put(check(id), Pair.of(str, ReturnType.STRING));
             strSize++;
@@ -123,7 +129,7 @@ public class Scope {
             return str;
         }
         
-        public int bool(String id) {
+        public int declareBool(String id) {
             int bool = boolSize;
             indices.put(check(id), Pair.of(bool, ReturnType.BOOLEAN));
             boolSize++;

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/functions/Function.java

@@ -10,26 +10,8 @@ package com.dfsek.terra.addons.terrascript.parser.lang.functions;
 import com.dfsek.terra.addons.terrascript.parser.lang.ImplementationArguments;
 import com.dfsek.terra.addons.terrascript.parser.lang.Expression;
 import com.dfsek.terra.addons.terrascript.parser.lang.Scope;
-import com.dfsek.terra.addons.terrascript.tokenizer.SourcePosition;
-
 
 public interface Function<T> extends Expression<T> {
-    Function<?> NULL = new Function<>() {
-        @Override
-        public ReturnType returnType() {
-            return null;
-        }
-
-        @Override
-        public Object evaluate(ImplementationArguments implementationArguments, Scope scope) {
-            return null;
-        }
-
-        @Override
-        public SourcePosition getPosition() {
-            return null;
-        }
-    };
     
     @Override
     default double applyDouble(ImplementationArguments implementationArguments, Scope scope) {

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/functions/FunctionSignature.java

@@ -0,0 +1,8 @@
+package com.dfsek.terra.addons.terrascript.parser.lang.functions;
+
+import com.dfsek.terra.addons.terrascript.parser.lang.Expression.ReturnType;
+import com.dfsek.terra.api.util.generic.pair.Pair;
+
+
+public record FunctionSignature(ReturnType returnType, Pair<String, ReturnType>[] arguments) {
+}

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/functions/UserDefinedFunctionBuilder.java

@@ -0,0 +1,73 @@
+package com.dfsek.terra.addons.terrascript.parser.lang.functions;
+
+import com.dfsek.terra.addons.terrascript.parser.lang.Block;
+import com.dfsek.terra.addons.terrascript.parser.lang.Expression;
+import com.dfsek.terra.addons.terrascript.parser.lang.Expression.ReturnType;
+import com.dfsek.terra.addons.terrascript.parser.lang.ImplementationArguments;
+import com.dfsek.terra.addons.terrascript.parser.lang.Scope;
+import com.dfsek.terra.addons.terrascript.parser.lang.Scope.ScopeBuilder;
+import com.dfsek.terra.addons.terrascript.tokenizer.SourcePosition;
+import com.dfsek.terra.api.util.generic.pair.Pair;
+
+import java.util.List;
+
+
+public class UserDefinedFunctionBuilder<T extends Function<?>> implements FunctionBuilder<T> {
+    
+    private final ReturnType returnType;
+    private final List<Pair<Integer, ReturnType>> argumentInfo;
+    private final ScopeBuilder bodyScopeBuilder;
+    private final Block body;
+    
+    public UserDefinedFunctionBuilder(ReturnType returnType, List<Pair<Integer, ReturnType>> argumentInfo, Block body, ScopeBuilder functionBodyScope) {
+        this.returnType = returnType;
+        this.bodyScopeBuilder = functionBodyScope;
+        this.body = body;
+        this.argumentInfo = argumentInfo;
+    }
+    
+    @Override
+    public T build(List<Expression<?>> argumentList, SourcePosition position) {
+        //noinspection unchecked
+        return (T) new Function() {
+           
+            private final ThreadLocal<Scope> threadLocalScope = ThreadLocal.withInitial(bodyScopeBuilder::build);
+            
+            @Override
+            public ReturnType returnType() {
+                return returnType;
+            }
+            
+            @Override
+            public Object evaluate(ImplementationArguments implementationArguments, Scope scope) {
+                Scope bodyScope = threadLocalScope.get();
+                // Pass arguments into scope of function body
+                for (int i = 0; i < argumentList.size(); i++) {
+                    Pair<Integer, ReturnType> argInfo = argumentInfo.get(i);
+                    Expression<?> argExpression = argumentList.get(i);
+                    switch(argInfo.getRight()) {
+                        case NUMBER -> bodyScope.setNum(argInfo.getLeft(), argExpression.applyDouble(implementationArguments, scope));
+                        case BOOLEAN -> bodyScope.setBool(argInfo.getLeft(), argExpression.applyBoolean(implementationArguments, scope));
+                        case STRING -> bodyScope.setStr(argInfo.getLeft(), (String) argExpression.evaluate(implementationArguments, scope));
+                    }
+                }
+                return body.evaluate(implementationArguments, bodyScope).data().evaluate(implementationArguments, scope);
+            }
+            
+            @Override
+            public SourcePosition getPosition() {
+                return position;
+            }
+        };
+    }
+    
+    @Override
+    public int argNumber() {
+        return argumentInfo.size();
+    }
+    
+    @Override
+    public ReturnType getArgument(int position) {
+        return argumentInfo.get(position).getRight();
+    }
+}

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/keywords/flow/BreakKeyword.java

@@ -7,14 +7,15 @@
 
 package com.dfsek.terra.addons.terrascript.parser.lang.keywords.flow;
 
-import com.dfsek.terra.addons.terrascript.parser.lang.Block;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationInfo;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationLevel;
 import com.dfsek.terra.addons.terrascript.parser.lang.ImplementationArguments;
 import com.dfsek.terra.addons.terrascript.parser.lang.Keyword;
 import com.dfsek.terra.addons.terrascript.parser.lang.Scope;
 import com.dfsek.terra.addons.terrascript.tokenizer.SourcePosition;
 
 
-public class BreakKeyword implements Keyword<Block.ReturnInfo<?>> {
+public class BreakKeyword implements Keyword<EvaluationInfo<?>> {
     private final SourcePosition position;
     
     public BreakKeyword(SourcePosition position) {
@@ -22,8 +23,8 @@ public class BreakKeyword implements Keyword<Block.ReturnInfo<?>> {
     }
     
     @Override
-    public Block.ReturnInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
+    public EvaluationInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
-        return new Block.ReturnInfo<>(Block.ReturnLevel.BREAK, null);
+        return new EvaluationInfo<>(EvaluationLevel.BREAK, null);
     }
     
     @Override

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/keywords/flow/ContinueKeyword.java

@@ -7,14 +7,15 @@
 
 package com.dfsek.terra.addons.terrascript.parser.lang.keywords.flow;
 
-import com.dfsek.terra.addons.terrascript.parser.lang.Block;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationInfo;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationLevel;
 import com.dfsek.terra.addons.terrascript.parser.lang.ImplementationArguments;
 import com.dfsek.terra.addons.terrascript.parser.lang.Keyword;
 import com.dfsek.terra.addons.terrascript.parser.lang.Scope;
 import com.dfsek.terra.addons.terrascript.tokenizer.SourcePosition;
 
 
-public class ContinueKeyword implements Keyword<Block.ReturnInfo<?>> {
+public class ContinueKeyword implements Keyword<EvaluationInfo<?>> {
     private final SourcePosition position;
     
     public ContinueKeyword(SourcePosition position) {
@@ -22,8 +23,8 @@ public class ContinueKeyword implements Keyword<Block.ReturnInfo<?>> {
     }
     
     @Override
-    public Block.ReturnInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
+    public EvaluationInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
-        return new Block.ReturnInfo<>(Block.ReturnLevel.CONTINUE, null);
+        return new EvaluationInfo<>(EvaluationLevel.CONTINUE, null);
     }
     
     @Override

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/keywords/flow/FailKeyword.java

@@ -7,14 +7,15 @@
 
 package com.dfsek.terra.addons.terrascript.parser.lang.keywords.flow;
 
-import com.dfsek.terra.addons.terrascript.parser.lang.Block;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationInfo;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationLevel;
 import com.dfsek.terra.addons.terrascript.parser.lang.ImplementationArguments;
 import com.dfsek.terra.addons.terrascript.parser.lang.Keyword;
 import com.dfsek.terra.addons.terrascript.parser.lang.Scope;
 import com.dfsek.terra.addons.terrascript.tokenizer.SourcePosition;
 
 
-public class FailKeyword implements Keyword<Block.ReturnInfo<?>> {
+public class FailKeyword implements Keyword<EvaluationInfo<?>> {
     private final SourcePosition position;
     
     public FailKeyword(SourcePosition position) {
@@ -22,8 +23,8 @@ public class FailKeyword implements Keyword<Block.ReturnInfo<?>> {
     }
     
     @Override
-    public Block.ReturnInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
+    public EvaluationInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
-        return new Block.ReturnInfo<>(Block.ReturnLevel.FAIL, null);
+        return new EvaluationInfo<>(EvaluationLevel.FAIL, null);
     }
     
     @Override

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/keywords/flow/ReturnKeyword.java

@@ -7,23 +7,30 @@
 
 package com.dfsek.terra.addons.terrascript.parser.lang.keywords.flow;
 
-import com.dfsek.terra.addons.terrascript.parser.lang.Block;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationInfo;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationLevel;
+import com.dfsek.terra.addons.terrascript.parser.lang.Expression;
 import com.dfsek.terra.addons.terrascript.parser.lang.ImplementationArguments;
 import com.dfsek.terra.addons.terrascript.parser.lang.Keyword;
 import com.dfsek.terra.addons.terrascript.parser.lang.Scope;
 import com.dfsek.terra.addons.terrascript.tokenizer.SourcePosition;
 
+import javax.annotation.Nullable;
 
-public class ReturnKeyword implements Keyword<Block.ReturnInfo<?>> {
+
+public class ReturnKeyword implements Keyword<EvaluationInfo<?>> {
     private final SourcePosition position;
     
-    public ReturnKeyword(SourcePosition position) {
+    private final Expression<?> data;
+    
+    public ReturnKeyword(@Nullable Expression<?> data, SourcePosition position) {
+        this.data = data;
         this.position = position;
     }
     
     @Override
-    public Block.ReturnInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
+    public EvaluationInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
-        return new Block.ReturnInfo<>(Block.ReturnLevel.RETURN, null);
+        return new EvaluationInfo<>(EvaluationLevel.RETURN, data);
     }
     
     @Override
@@ -35,4 +42,12 @@ public class ReturnKeyword implements Keyword<Block.ReturnInfo<?>> {
     public ReturnType returnType() {
         return ReturnType.VOID;
     }
+    
+    public ReturnType dataReturnType() {
+        if(data != null) {
+            return data.returnType();
+        } else {
+            return ReturnType.VOID;
+        }
+    }
 }

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/keywords/looplike/ForKeyword.java

@@ -8,6 +8,7 @@
 package com.dfsek.terra.addons.terrascript.parser.lang.keywords.looplike;
 
 import com.dfsek.terra.addons.terrascript.parser.lang.Block;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationLevel;
 import com.dfsek.terra.addons.terrascript.parser.lang.ImplementationArguments;
 import com.dfsek.terra.addons.terrascript.parser.lang.Keyword;
 import com.dfsek.terra.addons.terrascript.parser.lang.Expression;
@@ -15,7 +16,7 @@ import com.dfsek.terra.addons.terrascript.parser.lang.Scope;
 import com.dfsek.terra.addons.terrascript.tokenizer.SourcePosition;
 
 
-public class ForKeyword implements Keyword<Block.ReturnInfo<?>> {
+public class ForKeyword implements Keyword<Block.EvaluationInfo<?>> {
     private final Block conditional;
     private final Expression<?> initializer;
     private final Expression<Boolean> statement;
@@ -31,15 +32,15 @@ public class ForKeyword implements Keyword<Block.ReturnInfo<?>> {
     }
     
     @Override
-    public Block.ReturnInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
+    public Block.EvaluationInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
         for(initializer.evaluate(implementationArguments, scope);
             statement.evaluate(implementationArguments, scope);
             incrementer.evaluate(implementationArguments, scope)) {
-            Block.ReturnInfo<?> level = conditional.evaluate(implementationArguments, scope);
+            Block.EvaluationInfo<?> level = conditional.evaluate(implementationArguments, scope);
-            if(level.getLevel().equals(Block.ReturnLevel.BREAK)) break;
+            if(level.level().equals(EvaluationLevel.BREAK)) break;
-            if(level.getLevel().isReturnFast()) return level;
+            if(level.level().isReturnFast()) return level;
         }
-        return new Block.ReturnInfo<>(Block.ReturnLevel.NONE, null);
+        return new Block.EvaluationInfo<>(EvaluationLevel.NONE, null);
     }
     
     @Override

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/keywords/looplike/IfKeyword.java

@@ -7,6 +7,8 @@
 
 package com.dfsek.terra.addons.terrascript.parser.lang.keywords.looplike;
 
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationLevel;
+
 import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
@@ -20,7 +22,7 @@ import com.dfsek.terra.addons.terrascript.tokenizer.SourcePosition;
 import com.dfsek.terra.api.util.generic.pair.Pair;
 
 
-public class IfKeyword implements Keyword<Block.ReturnInfo<?>> {
+public class IfKeyword implements Keyword<Block.EvaluationInfo<?>> {
     private final Block conditional;
     private final Expression<Boolean> statement;
     private final SourcePosition position;
@@ -37,7 +39,7 @@ public class IfKeyword implements Keyword<Block.ReturnInfo<?>> {
     }
     
     @Override
-    public Block.ReturnInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
+    public Block.EvaluationInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
         if(statement.evaluate(implementationArguments, scope)) return conditional.evaluate(implementationArguments, scope);
         else {
             for(Pair<Expression<Boolean>, Block> pair : elseIf) {
@@ -47,7 +49,7 @@ public class IfKeyword implements Keyword<Block.ReturnInfo<?>> {
             }
             if(elseBlock != null) return elseBlock.evaluate(implementationArguments, scope);
         }
-        return new Block.ReturnInfo<>(Block.ReturnLevel.NONE, null);
+        return new Block.EvaluationInfo<>(EvaluationLevel.NONE, null);
     }
     
     @Override

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/parser/lang/keywords/looplike/WhileKeyword.java

@@ -8,6 +8,8 @@
 package com.dfsek.terra.addons.terrascript.parser.lang.keywords.looplike;
 
 import com.dfsek.terra.addons.terrascript.parser.lang.Block;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationInfo;
+import com.dfsek.terra.addons.terrascript.parser.lang.Block.EvaluationLevel;
 import com.dfsek.terra.addons.terrascript.parser.lang.ImplementationArguments;
 import com.dfsek.terra.addons.terrascript.parser.lang.Keyword;
 import com.dfsek.terra.addons.terrascript.parser.lang.Expression;
@@ -15,7 +17,7 @@ import com.dfsek.terra.addons.terrascript.parser.lang.Scope;
 import com.dfsek.terra.addons.terrascript.tokenizer.SourcePosition;
 
 
-public class WhileKeyword implements Keyword<Block.ReturnInfo<?>> {
+public class WhileKeyword implements Keyword<EvaluationInfo<?>> {
     private final Block conditional;
     private final Expression<Boolean> statement;
     private final SourcePosition position;
@@ -27,13 +29,13 @@ public class WhileKeyword implements Keyword<Block.ReturnInfo<?>> {
     }
     
     @Override
-    public Block.ReturnInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
+    public EvaluationInfo<?> evaluate(ImplementationArguments implementationArguments, Scope scope) {
         while(statement.evaluate(implementationArguments, scope)) {
-            Block.ReturnInfo<?> level = conditional.evaluate(implementationArguments, scope);
+            EvaluationInfo<?> level = conditional.evaluate(implementationArguments, scope);
-            if(level.getLevel().equals(Block.ReturnLevel.BREAK)) break;
+            if(level.level().equals(EvaluationLevel.BREAK)) break;
-            if(level.getLevel().isReturnFast()) return level;
+            if(level.level().isReturnFast()) return level;
         }
-        return new Block.ReturnInfo<>(Block.ReturnLevel.NONE, null);
+        return new EvaluationInfo<>(EvaluationLevel.NONE, null);
     }
     
     @Override

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/tokenizer/Token.java

@@ -76,9 +76,9 @@ public class Token {
     }
     
     public boolean isVariableDeclaration() {
-        return type.equals(Type.STRING_VARIABLE)
+        return type.equals(Type.TYPE_STRING)
-               || type.equals(Type.BOOLEAN_VARIABLE)
+               || type.equals(Type.TYPE_BOOLEAN)
-               || type.equals(Type.NUMBER_VARIABLE);
+               || type.equals(Type.TYPE_NUMBER);
     }
     
     public boolean isControlStructure() {
@@ -192,15 +192,19 @@ public class Token {
         /**
          * Numeric variable declaration
          */
-        NUMBER_VARIABLE,
+        TYPE_NUMBER,
         /**
          * String variable declaration
          */
-        STRING_VARIABLE,
+        TYPE_STRING,
         /**
          * Boolean variable declaration
          */
-        BOOLEAN_VARIABLE,
+        TYPE_BOOLEAN,
+        /**
+         * Void type declaration
+         */
+        TYPE_VOID,
         /**
          * If statement declaration
          */

common/addons/structure-terrascript-loader/src/main/java/com/dfsek/terra/addons/terrascript/tokenizer/Tokenizer.java

@@ -182,11 +182,13 @@ public class Tokenizer {
             return new Token(tokenString, Token.Type.BOOLEAN, reader.getPosition());
         
         if(tokenString.equals("num"))
-            return new Token(tokenString, Token.Type.NUMBER_VARIABLE, reader.getPosition());
+            return new Token(tokenString, Token.Type.TYPE_NUMBER, reader.getPosition());
         if(tokenString.equals("str"))
-            return new Token(tokenString, Token.Type.STRING_VARIABLE, reader.getPosition());
+            return new Token(tokenString, Token.Type.TYPE_STRING, reader.getPosition());
         if(tokenString.equals("bool"))
-            return new Token(tokenString, Token.Type.BOOLEAN_VARIABLE, reader.getPosition());
+            return new Token(tokenString, Token.Type.TYPE_BOOLEAN, reader.getPosition());
+        if(tokenString.equals("void"))
+            return new Token(tokenString, Token.Type.TYPE_VOID, reader.getPosition());
         
         if(tokenString.equals("if"))
             return new Token(tokenString, Token.Type.IF_STATEMENT, reader.getPosition());