Pretty syntax analysis errors

grammar.txt

@@ -48,7 +48,11 @@ restmult -> MUL prefixexpr restmult
 		  | MOD prefixexpr restmult
 		  | .
 
-prefixexpr -> NOT prefixexpr | ADD prefixexpr | SUB prefixexpr | PTR prefixexpr | postfixexpr .
+prefixexpr -> NOT prefixexpr
+			| ADD prefixexpr
+			| SUB prefixexpr
+			| PTR prefixexpr
+			| postfixexpr .
 
 postfixexpr -> primary postfixop .
 postfixop -> PTR postfixop | .

prg/pass.pins

@@ -11,6 +11,7 @@ var e = 'a', "test", 4
 var f = 1 * 3
 var g = 1 * 'a'
 var h = 4 * "aaa"
+var i =
 
 fun a() =
 	1, 'a', "a",

prg/test.pins

@@ -0,0 +1 @@
+var

src/pins25/phase/LexAn.java

@@ -130,7 +130,7 @@ public class LexAn implements AutoCloseable {
         Report.Location start = currentLocation();
         switch (buffChar) {
             case -1: // EOF
-                buffToken = new Token(new Report.Location(0, 0), Token.Symbol.EOF, null);
+                buffToken = new Token(start, Token.Symbol.EOF, null);
                 return;
 
             case '\'':

src/pins25/phase/SynAn.java

@@ -91,7 +91,7 @@ public class SynAn implements AutoCloseable {
                 break;
 
             default:
-                throw new Report.Error(token, "Unexpected symbol '" + token.lexeme() + "', expected FUN or VAR.");
+                throw new Report.Error(token, "Unexpected symbol '" + token.lexeme() + "', expected definition.");
         }
     }
 
@@ -198,25 +198,37 @@ public class SynAn implements AutoCloseable {
                 check(Token.Symbol.END);
                 break;
 
-            default:
+            case IDENTIFIER:
+            case LPAREN:
+            case ADD:
+            case SUB:
+            case NOT:
+            case PTR:
+            case INTCONST:
+            case CHARCONST:
+            case STRINGCONST:
                 System.out.println("statement -> expression exprassign");
                 parseExpression();
                 parseExpressionAssign();
+                break;
+
+            default:
+                throw new Report.Error(token, "Unexpected symbol '" + token.lexeme() + "', expected statement.");
         }
     }
 
     private void parseRestStatementDefinitions() {
         switch (lexAn.peekToken().symbol()) {
-            case IN:
-                System.out.println("reststmtdefs -> ε");
-                break;
-
             case FUN:
             case VAR:
                 System.out.println("reststmtdefs -> definition reststmtdefs");
                 parseDefinition();
                 parseRestStatementDefinitions();
                 break;
+
+            case IN:
+                System.out.println("reststmtdefs -> ε");
+                break;
         }
     }
 
@@ -256,7 +268,7 @@ public class SynAn implements AutoCloseable {
                 break;
 
             default:
-                throw new Report.Error(token, "Unexpected symbol '" + token.lexeme() + "', expected integer, character or string constant.");
+                throw new Report.Error(token, "Unexpected symbol '" + token.lexeme() + "', expected constant.");
         }
     }
 
@@ -302,12 +314,32 @@ public class SynAn implements AutoCloseable {
                 break;
 
             default:
-                throw new Report.Error(token, "Unexpected symbol '" + token.lexeme() + "', expected integer, character or string constant.");
+                throw new Report.Error(token, "Unexpected symbol '" + token.lexeme() + "', expected constant.");
         }
     }
 
+    private void checkExpression() {
+        Token token = lexAn.peekToken();
+        switch (token.symbol()) {
+            case IDENTIFIER:
+            case LPAREN:
+            case ADD:
+            case SUB:
+            case NOT:
+            case PTR:
+            case INTCONST:
+            case CHARCONST:
+            case STRINGCONST:
+                return;
+
+            default:
+                throw new Report.Error(token, "Unexpected symbol '" + token.lexeme() + "', expected expression.");
+        }
+    }
 
     private void parseExpression() {
+        checkExpression();
+
         System.out.println("expression -> conjexpr restdisj");
         parseConjunctionExpression();
         parseRestDisjunctions();
@@ -323,6 +355,8 @@ public class SynAn implements AutoCloseable {
     }
 
     private void parseConjunctionExpression() {
+        checkExpression();
+
         System.out.println("conjexpr -> cmpexpr restconj");
         parseComparisonExpression();
         parseRestConjunctionExpressions();
@@ -340,6 +374,8 @@ public class SynAn implements AutoCloseable {
     }
 
     private void parseComparisonExpression() {
+        checkExpression();
+
         System.out.println("cmpexpr -> addexpr restcmp");
         parseAdditionExpression();
         parseRestComparisons();
@@ -366,6 +402,8 @@ public class SynAn implements AutoCloseable {
     }
 
     private void parseAdditionExpression() {
+        checkExpression();
+
         System.out.println("addexpr -> multexpr restadd");
         parseMultiplicationExpression();
         parseRestAdditions();
@@ -389,6 +427,8 @@ public class SynAn implements AutoCloseable {
     }
 
     private void parseMultiplicationExpression() {
+        checkExpression();
+
         System.out.println("multexpr -> prefixexpr restmult");
         parsePrefixExpression();
         parseRestMultiplicationExpressions();
@@ -413,6 +453,8 @@ public class SynAn implements AutoCloseable {
     }
 
     private void parsePrefixExpression() {
+        checkExpression();
+
         Token token = lexAn.peekToken();
         switch (token.symbol()) {
             case ADD:
@@ -432,6 +474,8 @@ public class SynAn implements AutoCloseable {
     }
 
     private void parsePostfixExpression() {
+        checkExpression();
+
         System.out.println("postfixexpr -> primary postfixop");
         parsePrimary();
         parsePostfixOperator();