Bug fixes:

Catching Indentation Errors.
	A typo on regex of Identifiers
	Potential fixes on allowing function body with only definations. (not applied)
TODO:
	Allowing a program to have interleaving definations and statements?

src/main/cup/chocopy/pa1/ChocoPy.cup

@@ -1,4 +1,5 @@
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 
 import java_cup.runtime.*;
@@ -113,12 +114,26 @@ action code {:
         }
         return list;
     }
-
+    <T> List<T> combine(List<T> list, List<T> item) {
+        if (item != null) {
+            Iterator<T> it = item.iterator();
+            while(it.hasNext())
+                list.add(it.next());
+        }
+        return list;
+    }
     /** Return a mutable empty list. */
     <T> List<T> empty() {
         return new ArrayList<T>();
     }
-
+    class FuncBody {
+        public List<Declaration> fbd;
+        public List<Stmt> sl;
+        public FuncBody(List<Declaration> fbd, List<Stmt> sl){
+            this.fbd = fbd;
+            this.sl = sl;
+        }
+    }
     /** Return the leftmost non-whitespace location in NODES, or null if NODES
      *  is empty.  Assumes that the nodes of NODES are ordered in increasing
      *  order of location, from left to right. */
@@ -228,7 +243,7 @@ terminal String IS;
 
 /* Returned by the lexer for erroneous tokens.  Since it does not appear in
  * the grammar, it indicates a syntax error. */
-terminal UNRECOGNIZED;   
+terminal String UNRECOGNIZED;   
 
 /* Nonterminal symbols (defined in production rules below).
  * As for terminal symbols, 
@@ -236,7 +251,7 @@ terminal UNRECOGNIZED;
  * defines the listed nonterminal identifier symbols to have semantic values
  * of type <type>. */
 non terminal Program           program;
-non terminal List<Declaration> program_head, class_body, class_body_defs, fun_body_decs;
+non terminal List<Declaration> defs, program_head, opt_program_head, class_body, class_body_defs, fun_body_decs;
 non terminal List<Stmt>        stmt_list, opt_stmt_list, block, else_body;
 non terminal Stmt              stmt, simple_stmt;
 non terminal Expr              expr, pexpr, cexpr;
@@ -255,7 +270,7 @@ non terminal List<Expr>        opt_target, expr_list;
 non terminal Expr              target;
 non terminal MemberExpr        member_expr;
 non terminal IndexExpr         index_expr;
-
+non terminal FuncBody          fun_body;
 
 
 
@@ -330,7 +345,11 @@ typed_vars ::= typed_var:tv                                 {: RESULT= single(tv
               ; 
                   
              
-/* fun_body */            
+/* fun_body */   
+fun_body ::=  fun_body_decs:fbd stmt_list:sl                {: RESULT = new FuncBody(fbd, sl);:}
+            | fun_body_decs:fbd                             {: RESULT = new FuncBody(fbd, new ArrayList<Stmt>());:}
+            ;
+
 fun_body_decs ::= fun_body_decs:fbd  global_decl:gd         {: RESULT= combine(fbd, gd); :}
                 | fun_body_decs:fbd  nonlocal_decl:nd       {: RESULT= combine(fbd, nd); :} 
                 | fun_body_decs:fbd  var_def:vd             {: RESULT= combine(fbd, vd); :}

src/main/jflex/chocopy/pa1/ChocoPy.jflex

@@ -1,6 +1,7 @@
 package chocopy.pa1;
 import java_cup.runtime.*;
 import java.util.ArrayList;
+import java.util.Iterator;
 %%
 
 /*** Do not change the flags below unless you know what you are doing. ***/
@@ -37,6 +38,7 @@ import java.util.ArrayList;
     private int str_l = 0, str_c = 0; //Start location of a string.
     /*A stack that keeps track of the spaces in each Indentation Level*/
     private ArrayList<Integer> stack = new ArrayList<Integer>(20); 
+    private boolean indentErrorUnchecked = true;
     /** Return a terminal symbol of syntactic category TYPE and no
      *  semantic value at the current source location. */
     private Symbol symbol(int type) {
@@ -63,6 +65,15 @@ import java.util.ArrayList;
         if(stack.isEmpty()) return 0;
         return stack.get(stack.size() - 1);
     }
+    private boolean find(int indent){
+      if(indent == 0) return true;
+      Iterator<Integer> it = stack.iterator();
+      while(it.hasNext()){
+         if(it.next() == indent)
+            return true;
+      }
+      return false;
+    }
 %}
 
 /* Macros (regexes used in rules below) */
@@ -72,7 +83,7 @@ LineBreak  = \r|\n|\r\n
 
 IntegerLiteral = 0|[1-9][0-9]* // Accroding to the manual, 00+ is illeagal
 StringLiteral = ([^\"\\]|(\\\")|(\\t)|(\\r)|(\\n)|(\\\\))+ // \n, \r, \t, \\, \" and Anything except \ and " 
-Identifiers = (_|[a-z]|[A-Z])(_|[a-z]|[A-Z][0-9])* 
+Identifiers = (_|[a-z]|[A-Z])(_|[a-z]|[A-Z]|[0-9])* 
 Comments = #[^\r\n]*
 %%
 //YYINITIAL state is where we're dealing with indentations.
@@ -135,7 +146,18 @@ if True:
           AFTER state.
           */ 
           pop();
-          return symbol(ChocoPyTokens.DEDENT, currIndent);
+          if(top() < currIndent)
+          {
+            currIndent = top();
+            return symbolFactory.newSymbol("<bad indentation>", ChocoPyTokens.UNRECOGNIZED,
+              new ComplexSymbolFactory.Location(yyline + 1, yycolumn - 1),
+              new ComplexSymbolFactory.Location(yyline + 1,yycolumn + yylength()),
+              currIndent);
+          }
+          return symbolFactory.newSymbol(ChocoPyTokens.terminalNames[ChocoPyTokens.DEDENT], ChocoPyTokens.DEDENT,
+            new ComplexSymbolFactory.Location(yyline + 1, yycolumn - 1),
+            new ComplexSymbolFactory.Location(yyline + 1,yycolumn + yylength()),
+            currIndent);
       }
       /*Otherwise, we will start dealing with the rest 
         of the line after indentation in AFTER state. */
@@ -159,7 +181,7 @@ if True:
 <AFTER> {
 
   /* Delimiters. */
-  {LineBreak}                 {  yybegin(YYINITIAL); currIndent = 0;return symbol(ChocoPyTokens.NEWLINE);}
+  {LineBreak}                 {  yybegin(YYINITIAL); currIndent = 0;indentErrorUnchecked = true; return symbol(ChocoPyTokens.NEWLINE);}
   ":"                         { return symbol(ChocoPyTokens.COLON); }
   ","                         { return symbol(ChocoPyTokens.COMMA); }