Added Do statements and code blocks

1 files changed, 37 insertions, 15 deletions

diff --git a/src/Compiler/Parser.java b/src/Compiler/Parser.java
index 7eb22df..5288c67 100644
--- a/src/Compiler/Parser.java
+++ b/src/Compiler/Parser.java
@@ -3,6 +3,8 @@ package Compiler;
 import java.util.ArrayList;
 import java.util.List;
 
+import Compiler.Statement.BlockStatement;
+
 public class Parser {
     private final List<Token> tokens;
     private int currentToken = 0;
@@ -70,10 +72,24 @@ public class Parser {
         }else if (matchAndAdvance(TokenType.IF)){
             Statement statement = ifStatement();
             return statement;
+        }else if (matchAndAdvance(TokenType.DO)){
+            Statement statement = doStatement();
+            return statement;
         }
         return expressionStatement();
     }
 
+    private BlockStatement blockStatement(){
+        List<Statement> statements = new ArrayList<>();
+        while(!matchAndAdvance(TokenType.END)&&!checkToken(TokenType.ELSE)){
+            if(checkEOF()){
+                throw error("end missing from block");
+            }
+            statements.add(declaration());
+        }
+        return new Statement.BlockStatement(statements);
+    }
+
     private Statement printStatement(){
         matchOrError(TokenType.STAR, "Syntax, print *, item1, item2...");
         List<Expression> exprList = new ArrayList<>();
@@ -92,26 +108,32 @@ public class Parser {
     private Statement ifStatement(){
         Expression condition = expression();
         if(matchOrError(TokenType.THEN, "then expected after if statement")){
-            List<Statement> statements = new ArrayList<>();
-            List<Statement> elseStatements = new ArrayList<>();
-            while(!matchAndAdvance(TokenType.ENDIF)&&!checkToken(TokenType.ELSE)){
-                if(checkEOF()){
-                    throw error("endif missing");
-                }
-                statements.add(declaration());
-            }
+            Statement.BlockStatement ifBlock = blockStatement();
+            Statement.BlockStatement elseBlock=null;
+            
             if(matchAndAdvance(TokenType.ELSE)){
-                while(!matchAndAdvance(TokenType.ENDIF)){
-                    if(checkEOF()){
-                        throw error("endif missing");
-                    }
-                    elseStatements.add(declaration());
-                }
+                elseBlock=blockStatement();
             }
-            Statement ifstatement = new Statement.IfStatement(condition, statements,elseStatements);
+            matchOrError(TokenType.IF, "If statements end with if");
+            Statement ifstatement = new Statement.IfStatement(condition, ifBlock,elseBlock);
             return ifstatement;
         }
         return null;
+    }
+
+    private Statement doStatement(){
+        Expression variable =expression();
+        matchOrError(TokenType.EQUALS, "'=' missing");
+        Expression start = expression();
+        matchOrError(TokenType.COMMA, " use ',' between values");
+        Expression stop = expression();
+        Expression step = null;
+        if(matchAndAdvance(TokenType.COMMA)){
+           step = expression();
+        }
+        Statement.BlockStatement codeBlock = blockStatement();
+        matchOrError(TokenType.DO, "Do statements end with do");
+        return new Statement.DoStatement(variable, start, stop, step,codeBlock);
 
     }