range loop working

src/ast_compiler.rs

@@ -1,12 +1,18 @@
 use crate::ast_compiler::Expression::{
-    FieldGet, FunctionCall, ListGet, MapGet, MethodCall, NamedParameter, Stop, Variable,
+    Assignment, FieldGet, FunctionCall, ListGet, MapGet, MethodCall, NamedParameter, Stop, Variable,
 };
 use crate::errors::CompilerError::{
     self, Expected, ParseError, TooManyParameters, UnexpectedIndent, UninitializedVariable,
 };
 use crate::errors::CompilerErrorAtLine;
 use crate::symbol_builder::{Symbol, calculate_type, infer_type};
-use crate::tokens::TokenType::{Bang, Bool, Char, Colon, DateTime, Dot, Eof, Eol, Equal, False, FloatingPoint, Fn, Greater, GreaterEqual, GreaterGreater, Identifier, If, Indent, Integer, LeftBrace, LeftBracket, LeftParen, Less, LessEqual, LessLess, Let, ListType, MapType, Minus, Object, Plus, Print, RightBrace, RightBracket, RightParen, SingleRightArrow, Slash, Star, StringType, True, U32, U64, Unknown, Else};
+use crate::tokens::TokenType::{
+    Bang, Bool, Char, Colon, DateTime, Dot, Else, Eof, Eol, Equal, False, FloatingPoint, Fn, For,
+    Greater, GreaterEqual, GreaterGreater, Identifier, If, In, Indent, Integer, LeftBrace,
+    LeftBracket, LeftParen, Less, LessEqual, LessLess, Let, ListType, MapType, Minus, Object, Plus,
+    Print, Range, RightBrace, RightBracket, RightParen, SingleRightArrow, Slash, Star, StringType,
+    True, U32, U64, Unknown,
+};
 use crate::tokens::{Token, TokenType};
 use crate::value::Value;
 use crate::{Expr, Stmt, SymbolTable};
@@ -66,6 +72,9 @@ impl AstCompiler {
         if !self.had_error {
             let mut statements = vec![];
             while !self.is_at_end() {
+                if self.match_token(&[Eol]) {
+                    continue;
+                }
                 let statement = self.indent(symbol_table)?;
                 if let Some(statement) = statement {
                     statements.push(statement);
@@ -316,11 +325,29 @@ impl AstCompiler {
             self.print_statement(symbol_table)
         } else if self.match_token(&[If]) {
             self.if_statement(symbol_table)
+        } else if self.match_token(&[For]) {
+            self.for_statement(symbol_table)
         } else {
             self.expr_statement(symbol_table)
         }
     }
 
+    fn for_statement(&mut self, symbol_table: &mut SymbolTable) -> Stmt {
+        let loop_var = self.consume(&Identifier, Expected("loop variable name."))?;
+        self.consume(&In, Expected("'in' after loop variable name."))?;
+        let range = self.expression(symbol_table)?;
+        self.consume(&Colon, Expected("colon after range expression"))?;
+        self.consume(&Eol, Expected("end of line after for expression."))?;
+        self.inc_indent();
+        let body = self.compile(symbol_table)?;
+
+        Ok(Statement::ForStatement {
+            loop_var,
+            range,
+            body,
+        })
+    }
+
     fn if_statement(&mut self, symbol_table: &mut SymbolTable) -> Stmt {
         let condition = self.expression(symbol_table)?;
         self.consume(&Colon, Expected("':' after if condition."))?;
@@ -337,7 +364,11 @@ impl AstCompiler {
         } else {
             None
         };
-        Ok(Statement::IfStatement {condition, then_branch, else_branch})
+        Ok(Statement::IfStatement {
+            condition,
+            then_branch,
+            else_branch,
+        })
     }
 
     fn inc_indent(&mut self) {
@@ -389,7 +420,21 @@ impl AstCompiler {
 
     fn assignment(&mut self, symbol_table: &mut SymbolTable) -> Expr {
         let expr = self.equality(symbol_table)?;
-        self.binary(&[TokenType::Equal], expr, symbol_table)
+        if self.match_token(&[Equal]) {
+            let operator = self.previous().clone();
+            let right = self.comparison(symbol_table)?;
+            if let Variable { name, .. } = expr {
+                Ok(Assignment {
+                    line: operator.line,
+                    variable_name: name.to_string(),
+                    value: Box::new(right),
+                })
+            } else {
+                Err(self.raise(CompilerError::Failure))
+            }
+        } else {
+            Ok(expr)
+        }
     }
 
     fn equality(&mut self, symbol_table: &mut SymbolTable) -> Expr {
@@ -402,7 +447,7 @@ impl AstCompiler {
     }
 
     fn comparison(&mut self, symbol_table: &mut SymbolTable) -> Expr {
-        let expr = self.bitshift(symbol_table)?;
+        let expr = self.range(symbol_table)?;
         self.binary(
             &[Greater, GreaterEqual, Less, LessEqual],
             expr,
@@ -410,6 +455,20 @@ impl AstCompiler {
         )
     }
 
+    fn range(&mut self, symbol_table: &mut SymbolTable) -> Expr {
+        let mut expr = self.bitshift(symbol_table)?;
+        if self.match_token(&[Range]) {
+            let operator = self.previous().clone();
+            let right = self.expression(symbol_table)?;
+            expr = Expression::Range {
+                line: operator.line,
+                lower: Box::new(expr),
+                upper: Box::new(right),
+            };
+        }
+        Ok(expr)
+    }
+
     fn bitshift(&mut self, symbol_table: &mut SymbolTable) -> Expr {
         let expr = self.term(symbol_table)?;
         self.binary(&[GreaterGreater, LessLess], expr, symbol_table)
@@ -805,11 +864,16 @@ pub enum Statement {
         if_expr: Expression,
         then_expr: Expression,
     },
-    IfStatement{
+    IfStatement {
         condition: Expression,
         then_branch: Vec<Statement>,
-        else_branch: Option<Vec<Statement>>
+        else_branch: Option<Vec<Statement>>,
-    }
+    },
+    ForStatement {
+        loop_var: Token,
+        range: Expression,
+        body: Vec<Statement>,
+    },
 }
 
 impl Statement {
@@ -822,6 +886,7 @@ impl Statement {
             Statement::ObjectStmt { name, .. } => name.line,
             Statement::GuardStatement { if_expr, .. } => if_expr.line(),
             Statement::IfStatement { condition, .. } => condition.line(),
+            Statement::ForStatement { loop_var, .. } => loop_var.line,
         }
     }
 }
@@ -867,6 +932,11 @@ pub enum Expression {
         literaltype: TokenType,
         value: Value,
     },
+    Range {
+        line: usize,
+        lower: Box<Expression>,
+        upper: Box<Expression>,
+    },
     List {
         line: usize,
         literaltype: TokenType,
@@ -882,6 +952,11 @@ pub enum Expression {
         name: String,
         var_type: TokenType,
     },
+    Assignment {
+        line: usize,
+        variable_name: String,
+        value: Box<Expression>,
+    },
     FunctionCall {
         line: usize,
         name: String,
@@ -922,9 +997,11 @@ impl Expression {
             Self::Unary { line, .. } => *line,
             Self::Grouping { line, .. } => *line,
             Self::Literal { line, .. } => *line,
+            Self::Range { line, .. } => *line,
             Self::List { line, .. } => *line,
             Self::Map { line, .. } => *line,
             Variable { line, .. } => *line,
+            Assignment { line, .. } => *line,
             FunctionCall { line, .. } => *line,
             MethodCall { line, .. } => *line,
             Stop { line } => *line,

src/bytecode_compiler.rs

@@ -7,10 +7,10 @@ use crate::errors::{CompilerError, CompilerErrorAtLine};
 use crate::symbol_builder::{Symbol, calculate_type, infer_type};
 use crate::tokens::TokenType;
 use crate::tokens::TokenType::Unknown;
-use crate::value::{Value};
+use crate::value::Value;
 use crate::vm::{
     OP_ADD, OP_AND, OP_ASSIGN, OP_BITAND, OP_BITOR, OP_BITXOR, OP_CALL, OP_CALL_BUILTIN,
-    OP_CONSTANT, OP_DEF_LIST, OP_DEF_MAP, OP_DIVIDE, OP_EQUAL, OP_GET, OP_GREATER,
+    OP_CONSTANT, OP_DEF_LIST, OP_DEF_MAP, OP_DIVIDE, OP_EQUAL, OP_GET, OP_GOTO_IF, OP_GREATER,
     OP_GREATER_EQUAL, OP_IF, OP_IF_ELSE, OP_LESS, OP_LESS_EQUAL, OP_LIST_GET, OP_MULTIPLY,
     OP_NEGATE, OP_NOT, OP_OR, OP_POP, OP_PRINT, OP_RETURN, OP_SHL, OP_SHR, OP_SUBTRACT,
 };
@@ -76,6 +76,7 @@ impl Compiler {
         }
     }
 
+    /// compile the entire AST into a chunk, adding a RETURN OP
     pub(crate) fn compile(
         &mut self,
         ast: &Vec<Statement>,
@@ -83,20 +84,28 @@ impl Compiler {
         registry: &mut Registry,
         namespace: &str,
     ) -> Result<Chunk, CompilerErrorAtLine> {
-        for statement in ast {
+        self.compile_statements(ast, symbols, registry, namespace)?;
-            self.compile_statement(statement, symbols, registry, namespace)?;
-        }
-
         self.emit_byte(OP_RETURN);
         let chunk = self.chunk.clone();
         self.chunk.code.clear(); // in case the compiler is reused, clear it for the next compilation. This is for the REPL
         Ok(chunk)
     }
 
-    fn raise(&self, error: CompilerError) -> CompilerErrorAtLine {
+    /// compile the entire AST into a chunk
-        CompilerErrorAtLine::raise(error, self.current_line)
+    fn compile_statements(
+        &mut self,
+        ast: &Vec<Statement>,
+        symbols: &SymbolTable,
+        registry: &mut Registry,
+        namespace: &str,
+    ) -> Result<(), CompilerErrorAtLine> {
+        for statement in ast {
+            self.compile_statement(statement, symbols, registry, namespace)?;
+        }
+        Ok(())
     }
 
+    /// compile a single statement
     fn compile_statement(
         &mut self,
         statement: &Statement,
@@ -174,6 +183,38 @@ impl Compiler {
                     )?;
                 }
             }
+            Statement::ForStatement {
+                loop_var,
+                range,
+                body,
+            } => {
+                // 1. step var index
+                let step_const_index = self.emit_constant(Value::I64(1));
+                // 2. range expression
+                self.compile_expression(namespace, range, symbols, registry)?;
+                //save the constants for lower and upper bounds of the range
+                let start_index = self.chunk.constants.len() - 1;
+                let end_index = self.chunk.constants.len() - 2;
+
+                let name = loop_var.lexeme.as_str();
+                let loop_var_name_index = self.chunk.add_var(&loop_var.token_type, name);
+                self.vars.insert(name.to_string(), loop_var_name_index);
+
+                // 3. start index
+                self.emit_bytes(OP_CONSTANT, start_index as u16);
+                self.emit_bytes(OP_ASSIGN, loop_var_name_index as u16);
+
+                let return_addr = self.chunk.code.len();
+                self.compile_statements(body, symbols, registry, namespace)?;
+                self.emit_bytes(OP_GET, loop_var_name_index as u16);
+                self.emit_bytes(OP_CONSTANT, step_const_index);
+                self.emit_byte(OP_ADD);
+                self.emit_bytes(OP_ASSIGN, loop_var_name_index as u16);
+                self.emit_bytes(OP_CONSTANT, end_index as u16);
+                self.emit_bytes(OP_GET, loop_var_name_index as u16);
+                self.emit_byte(OP_GREATER_EQUAL);
+                self.emit_bytes(OP_GOTO_IF, return_addr as u16);
+            }
         }
         Ok(())
     }
@@ -262,6 +303,15 @@ impl Compiler {
                     return Err(self.raise(UndeclaredVariable(name.to_string())));
                 }
             }
+            Expression::Assignment { variable_name, value, .. } => {
+                self.compile_expression(namespace, value, symbols, registry)?;
+                let name_index = self.vars.get(variable_name);
+                if let Some(name_index) = name_index {
+                    self.emit_bytes(OP_ASSIGN, *name_index as u16);
+                } else {
+                    return Err(self.raise(UndeclaredVariable(variable_name.to_string())));
+                }
+            }
             Expression::Literal { value, .. } => {
                 self.emit_constant(value.clone());
             }
@@ -343,6 +393,11 @@ impl Compiler {
             }
             Expression::MapGet { .. } => {}
             Expression::FieldGet { .. } => {}
+            Expression::Range { lower, upper, .. } => {
+                // opposite order, because we have to assign last one first to the loop variable
+                self.compile_expression(namespace, upper, symbols, registry)?;
+                self.compile_expression(namespace, lower, symbols, registry)?;
+            }
         }
         Ok(())
     }
@@ -393,4 +448,8 @@ impl Compiler {
         self.emit_bytes(OP_CONSTANT, index);
         index
     }
+
+    fn raise(&self, error: CompilerError) -> CompilerErrorAtLine {
+        CompilerErrorAtLine::raise(error, self.current_line)
+    }
 }

src/chunk.rs

@@ -5,7 +5,7 @@ use crate::vm::{
     OP_ADD, OP_BITAND, OP_BITOR, OP_BITXOR, OP_CALL, OP_CONSTANT, OP_DEF_BOOL, OP_DEF_F32,
     OP_DEF_F64, OP_DEF_I32, OP_DEF_I64, OP_DEF_LIST, OP_DEF_MAP, OP_DEF_STRING, OP_DEFINE,
     OP_DIVIDE, OP_EQUAL, OP_GET, OP_GREATER, OP_GREATER_EQUAL, OP_LESS, OP_LESS_EQUAL, OP_MULTIPLY,
-    OP_NEGATE, OP_NOT, OP_POP, OP_PRINT, OP_RETURN, OP_SHL, OP_SHR, OP_SUBTRACT,
+    OP_NEGATE, OP_NOT, OP_POP, OP_PRINT, OP_RETURN, OP_SHL, OP_SHR, OP_SUBTRACT,OP_ASSIGN,OP_GOTO_IF
 };
 use std::collections::HashMap;
 
@@ -117,9 +117,11 @@ impl Chunk {
             OP_DEF_F64 => self.constant_inst("DEFF64", offset),
             OP_DEF_BOOL => self.constant_inst("DEFBOOL", offset),
             OP_CALL => self.call_inst("CALL", offset),
-            OP_GET => self.constant_inst("GET", offset),
+            OP_GET => self.assign_inst("GET", offset),
             OP_DEF_LIST => self.new_inst("DEFLIST", offset),
             OP_DEF_MAP => self.new_inst("DEFMAP", offset),
+            OP_ASSIGN => self.assign_inst("ASSIGN", offset),
+            OP_GOTO_IF => self.constant_inst("GOTO_IF", offset),
             _ => {
                 println!("Unknown instruction {}", instruction);
                 offset + 1
@@ -132,6 +134,13 @@ impl Chunk {
         offset + 1
     }
 
+    fn assign_inst(&self, op: &str, offset: usize) -> usize {
+        let constant = self.code[offset + 1];
+        print!("{} {}:", op, constant);
+        println!("{}",self.vars.get(constant as usize).unwrap().1);
+        offset + 2
+    }
+
     fn call_inst(&self, op: &str, offset: usize) -> usize {
         let constant = self.code[offset + 1];
         let num_args = self.code[offset + 2];

src/compiler_tests.rs

@@ -156,7 +156,7 @@ object Person:
 
 let p = Person(name: 0x42)
 p"#);
-        assert!(r.is_err());
+        // assert!(r.is_err());
         assert_eq!(
             r#"Compilation failed: error at line 5, Expected string, found integer"#,
             format!("{}", r.unwrap_err().to_string())
@@ -386,6 +386,24 @@ else:
         );
     }
 
+    #[test]
+    fn inline_comment(){
+        assert_eq!(run(r#"// this is a comment"#), Ok(Value::Void));
+    }
+
+    #[test]
+    fn range_loop() {
+        assert_eq!(
+            run(r#"
+let sum=0
+for a in 1..4:
+    sum = sum + a
+sum
+"#),
+            Ok(Value::I64(10))
+        );
+    }
+
     // #[test]
     // fn package() {
     //     assert_eq!(run(r#"a.b.c()"#), Ok(Value::U32(48)));

src/keywords.rs

@@ -13,6 +13,7 @@ pub(crate) fn get_keyword(lexeme: &str) -> Option<TokenType> {
         "fn" => Some(TokenType::Fn),
         "for" => Some(TokenType::For),
         "if" => Some(TokenType::If),
+        "in" => Some(TokenType::In),
         "i32" => Some(TokenType::I32),
         "i64" => Some(TokenType::I64),
         "let" => Some(TokenType::Let),

src/lib.rs

@@ -7,6 +7,7 @@ use crate::symbol_builder::Symbol;
 use std::collections::HashMap;
 use std::fs;
 use walkdir::WalkDir;
+use crate::value::Value::Void;
 
 pub mod ast_compiler;
 mod builtins;
@@ -92,6 +93,7 @@ pub(crate) fn run(src: &str) -> Result<value::Value, CrudLangError> {
         symbol_builder::build("", &ast, &mut symbol_table);
         let mut registry = HashMap::new();
         bytecode_compiler::compile(None, &ast, &symbol_table, &mut registry)?;
+
         let registry = arc_swap::ArcSwap::from(std::sync::Arc::new(registry));
         vm::interpret(registry.load(), "main").map_err(CrudLangError::from)
 }

src/repl.rs

@@ -2,7 +2,7 @@ use crate::chunk::Chunk;
 use crate::errors::CrudLangError;
 use crate::scanner::scan;
 use crate::vm::Vm;
-use crate::{ast_compiler, bytecode_compiler, map_underlying, recompile, symbol_builder};
+use crate::{ast_compiler, bytecode_compiler, map_underlying, symbol_builder};
 use arc_swap::ArcSwap;
 use std::collections::HashMap;
 use std::io;

src/scanner.rs

@@ -142,7 +142,7 @@ impl Scanner {
                     if c == '0' && self.peek() == 'x' {
                         self.hex_number()?;
                     } else if c.is_ascii_digit() {
-                        self.number();
+                        self.number_or_range();
                     } else if is_alpha(c) {
                         self.identifier();
                     } else {
@@ -181,7 +181,7 @@ impl Scanner {
         Ok(())
     }
 
-    fn number(&mut self) {
+    fn number_or_range(&mut self) {
         while self.peek().is_ascii_digit() {
             self.advance();
         }
@@ -190,13 +190,30 @@ impl Scanner {
             has_dot = true;
             self.advance();
         }
-
+        if self.peek() == '.' && self.peek_next() == '.' {
+            self.range_expression()
+        } else {
             while is_digit_or_scientific(self.peek()) {
                 self.advance();
             }
             let value: String = self.chars[self.start..self.current].iter().collect();
             self.add_token_with_value(if has_dot { FloatingPoint } else { Integer }, value);
         }
+    }
+
+    fn range_expression(&mut self) {
+        let lower: String = self.chars[self.start..self.current].iter().collect();
+        self.match_next('.');
+        self.match_next('.');
+        self.add_token_with_value(Integer, lower);
+        self.add_token(TokenType::Range);
+        self.start = self.current;
+        while self.peek().is_ascii_digit() {
+            self.advance();
+        }
+        let upper: String = self.chars[self.start..self.current].iter().collect();
+        self.add_token_with_value(Integer, upper);
+    }
 
     fn char(&mut self) -> Result<(), CompilerErrorAtLine> {
         while self.peek() != '\'' && !self.is_at_end() {
@@ -265,11 +282,15 @@ impl Scanner {
     }
 
     fn peek_next(&self) -> char {
+        if self.current + 1 >= self.chars.len() {
+            '\0'
+        } else {
             self.chars[self.current + 1]
         }
+    }
 
     fn match_next(&mut self, expected: char) -> bool {
-        if self.is_at_end() || self.chars[self.current] != expected{
+        if self.is_at_end() || self.chars[self.current] != expected {
             false
         } else {
             self.current += 1;
@@ -304,7 +325,6 @@ struct Scanner {
     new_line: bool,
 }
 
-
 fn is_digit_or_scientific(c: char) -> bool {
     c.is_ascii_digit() || c == 'e' || c == 'E'
 }

src/symbol_builder.rs

@@ -1,5 +1,5 @@
 use crate::ast_compiler::{Expression, Parameter, Statement};
-use crate::builtins::{Signature, lookup};
+use crate::builtins::lookup;
 use crate::errors::CompilerError;
 use crate::errors::CompilerError::IncompatibleTypes;
 use crate::tokens::TokenType::{
@@ -186,6 +186,7 @@ pub fn infer_type(expr: &Expression, symbols: &HashMap<String, Symbol>) -> Token
             }
         }
         Expression::Variable { var_type, .. } => var_type.clone(),
+        Expression::Assignment { value, .. } => infer_type(value, symbols),
         Expression::FunctionCall { name, .. } => {
             let symbol = symbols.get(name);
             match symbol {
@@ -203,7 +204,7 @@ pub fn infer_type(expr: &Expression, symbols: &HashMap<String, Symbol>) -> Token
                 if let Ok(signature) = lookup(&value.to_string(), method_name) {
                     signature.return_type.clone()
                 } else {
-                    unreachable!()//?
+                    unreachable!() //?
                 }
             } else {
                 infer_type(receiver, symbols)
@@ -215,5 +216,6 @@ pub fn infer_type(expr: &Expression, symbols: &HashMap<String, Symbol>) -> Token
         Expression::ListGet { .. } => TokenType::Unknown,
         Expression::MapGet { .. } => TokenType::Unknown,
         Expression::FieldGet { .. } => TokenType::Unknown,
+        Expression::Range { lower, .. } => infer_type(lower, symbols),
     }
 }

src/tokens.rs

@@ -51,6 +51,7 @@ pub enum TokenType {
     I64,
     Identifier,
     If,
+    In,
     Indent,
     Integer,
     SignedInteger,
@@ -73,6 +74,7 @@ pub enum TokenType {
     Plus,
     Print,
     Question,
+    Range,
     Return,
     RightParen,
     RightBrace,
@@ -132,6 +134,7 @@ impl fmt::Display for TokenType {
             TokenType::Hex => write!(f, "0x"),
             TokenType::If => write!(f, "if"),
             TokenType::Identifier => write!(f, "identifier"),
+            TokenType::In => write!(f, "in"),
             TokenType::Indent => write!(f, "indent"),
             TokenType::Integer => write!(f, "integer"),
             TokenType::LeftBrace => write!(f, "{{"),
@@ -150,6 +153,7 @@ impl fmt::Display for TokenType {
             TokenType::Plus => write!(f, "+"),
             TokenType::Print => write!(f, "print"),
             TokenType::Question => write!(f, "?"),
+            TokenType::Range => write!(f, ".."),
             TokenType::Return => write!(f, "return"),
             TokenType::RightParen => write!(f, ")"),
             TokenType::RightBrace => write!(f, "}}"),

src/vm.rs

@@ -1,3 +1,4 @@
+use crate::Registry;
 use crate::chunk::Chunk;
 use crate::errors::RuntimeError::Something;
 use crate::errors::{RuntimeError, ValueError};
@@ -7,7 +8,6 @@ use arc_swap::Guard;
 use std::collections::HashMap;
 use std::sync::Arc;
 use tracing::debug;
-use crate::Registry;
 
 pub struct Vm {
     ip: usize,
@@ -17,14 +17,15 @@ pub struct Vm {
     pub(crate) registry: Arc<HashMap<String, Chunk>>,
 }
 
-
 pub fn interpret(
     registry: Guard<Arc<HashMap<String, Chunk>>>,
     function: &str,
 ) -> Result<Value, RuntimeError> {
     let chunk = registry.get(function).unwrap().clone();
+    // chunk.disassemble();
     let mut vm = Vm::new(&registry);
     vm.run(&get_context(function), &chunk)
+    // Ok(Value::Void)
 }
 
 pub async fn interpret_async(
@@ -57,7 +58,7 @@ fn value_map(strings: HashMap<String, String>) -> HashMap<Value, Value> {
 }
 
 pub fn interpret_function(chunk: &Chunk, args: Vec<Value>) -> Result<Value, RuntimeError> {
-    let mut vm = Vm::new(& Arc::new(HashMap::new()));
+    let mut vm = Vm::new(&Arc::new(HashMap::new()));
     vm.run_function(chunk, args)
 }
 
@@ -157,7 +158,7 @@ impl Vm {
                     let (var_type, name) = chunk.vars.get(index).unwrap();
                     let value = self.pop();
                     let value = Self::number(var_type, value)?;
-                    self.local_vars.insert(name.to_string(), value);
+                    self.local_vars.insert(name.to_string(), value); //insert or update
                 }
                 OP_DEF_MAP => {
                     let len = self.read(chunk);
@@ -172,7 +173,7 @@ impl Vm {
                 OP_GET => {
                     let var_index = self.read(chunk);
                     let (_, name_index) = chunk.vars.get(var_index).unwrap();
-                    let value = self.local_vars.remove(name_index).unwrap();
+                    let value = self.local_vars.get(name_index).unwrap().clone();
                     self.push(value);
                 }
                 OP_LIST_GET => {
@@ -196,10 +197,11 @@ impl Vm {
                     }
                     args.reverse();
                     let receiver = self.pop();
-                    let return_value = crate::builtins::call(&receiver_type_name, &function_name, receiver, args)?;
+                    let return_value =
+                        crate::builtins::call(&receiver_type_name, &function_name, receiver, args)?;
                     self.push(return_value);
                 }
-                OP_POP =>{
+                OP_POP => {
                     self.pop(); // discards the value
                 }
                 OP_CALL => {
@@ -232,10 +234,7 @@ impl Vm {
                             }
 
                             let mut fields = vec![];
-                            params
+                            params.iter().zip(args).for_each(|(param, arg)| {
-                                .iter()
-                                .zip(args)
-                                .for_each(|(param, arg)| {
                                 fields.push((param.name.lexeme.clone(), arg))
                             });
                             let new_instance = Value::ObjectType(Box::new(Object {
@@ -254,7 +253,7 @@ impl Vm {
                 OP_IF => {
                     let condition = self.pop();
                     if condition == Value::Bool(true) {
-                        if let Some(then) = self.registry.get(&format!("{}.?",chunk.name)){
+                        if let Some(then) = self.registry.get(&format!("{}.?", chunk.name)) {
                             let result = interpret_function(then, vec![])?;
                             self.push(result);
                         }
@@ -263,19 +262,26 @@ impl Vm {
                 OP_IF_ELSE => {
                     let condition = self.pop();
                     self.push(if condition == Value::Bool(true) {
-                        if let Some(then) = self.registry.get(&format!("{}.?",chunk.name)){
+                        if let Some(then) = self.registry.get(&format!("{}.?", chunk.name)) {
                             interpret_function(then, vec![])?
                         } else {
                             return Err(Something);
                         }
                     } else {
-                        if let Some(then) = self.registry.get(&format!("{}.:",chunk.name)){
+                        if let Some(then) = self.registry.get(&format!("{}.:", chunk.name)) {
                             interpret_function(then, vec![])?
                         } else {
                             return Err(Something);
                         }
                     });
                 }
+                OP_GOTO_IF => {
+                    let b = self.pop();
+                    let goto_addr = self.read(chunk);
+                    if b == Value::Bool(true) {
+                        self.ip = goto_addr;
+                    }
+                }
                 _ => {}
             }
         }
@@ -389,3 +395,4 @@ pub const OP_LIST_GET: u16 = 42;
 pub const OP_CALL_BUILTIN: u16 = 43;
 pub const OP_IF: u16 = 44;
 pub const OP_IF_ELSE: u16 = 45;
+pub const OP_GOTO_IF: u16 = 46;