Add break-keyword

examples/test.lua

@@ -42,4 +42,7 @@ global value, table = f(10, 11, 12)
 print("hello")
 for i=1,#table do
     print(table[i])
+    if i > 2 then
+        break
+    end
 end

src/ast.rs

@@ -263,6 +263,7 @@ pub enum Statement {
         Node<Expression>,
         Block,
     ),
+    Break,
 }
 
 impl Parse for Statement {
@@ -354,6 +355,9 @@ impl Parse for Statement {
             ))
         } else if let Ok(expr) = stream.parse() {
             Ok(Self::Expression(expr))
+        } else if let Some(Token::Keyword(Keyword::Break)) = stream.peek() {
+            stream.next();
+            Ok(Self::Break)
         } else {
             Err(stream.expecting_err("statement"))
         }

src/compile.rs

@@ -179,6 +179,7 @@ impl Statement {
                 constants.extend(block.find_constants(scope, Vec::new()));
                 constants
             }
+            Statement::Break => HashSet::new(),
         }
     }
 
@@ -417,13 +418,20 @@ impl Statement {
                 let instr_len = instr.len() as i32;
 
                 instructions.push(PreInstr::Instr(Instruction::Jmp(instr_len + 2)));
-                instructions.extend(instr);
+                for (i, pre_instr) in instr.into_iter().enumerate() {
+                    match pre_instr {
+                        PreInstr::Break => instructions
+                            .push(PreInstr::Instr(Instruction::Jmp(instr_len - i as i32 + 1))),
+                        _ => instructions.push(pre_instr),
+                    }
+                }
 
                 instructions.push(PreInstr::Instr(Instruction::Add(
                     *init_reg, *init_reg, *step_reg,
                 )));
                 instructions.push(PreInstr::Instr(Instruction::Jmp(-(instr_len + 4))));
             }
+            Statement::Break => instructions.push(PreInstr::Break),
         }
 
         for reg in 0..scope.register_counter.0 {

src/token_stream/lexer.rs

@@ -22,6 +22,7 @@ pub enum Keyword {
     Not,
     For,
     Do,
+    Break,
 }
 
 impl Keyword {
@@ -40,6 +41,7 @@ impl Keyword {
             "not" => Keyword::Not,
             "for" => Keyword::For,
             "do" => Keyword::Do,
+            "break" => Keyword::Break,
             _ => None?,
         })
     }
@@ -61,6 +63,7 @@ impl ToString for Keyword {
             Keyword::Not => "not",
             Keyword::For => "for",
             Keyword::Do => "do",
+            Keyword::Break => "break",
         }
         .to_string()
     }