Minor cleanup.

expr.c

@@ -2,5 +2,5 @@
 
 void VisitBinary(struct binary);
 void VisitGrouping(struct grouping);
-void VisitLiteral(struct literal);
+void VisitLiteral(Token);
 void VisitUnary(struct unary);

expr.h

@@ -24,11 +24,6 @@ struct grouping {
     struct Expr* expression;
 };
 
-struct literal {
-    Token* type;
-    void* object;
-};
-
 struct unary {
     Token* op;
     struct Expr* right;
@@ -39,14 +34,14 @@ struct Expr {
     union ex {
         struct binary Binary;
         struct grouping Grouping;
-        struct literal Literal;
+        Token* Literal;
         struct unary Unary;
     } expression;
 };
 
 void VisitBinary(struct binary);
 void VisitGrouping(struct grouping);
-void VisitLiteral(struct literal);
+void VisitLiteral(Token);
 void VisitUnary(struct unary);
 
 #endif

lox.c

@@ -42,6 +42,7 @@ void RunFile(const char* path) {
     printf("TREE:\n");
     Expr* tree = GenerateExpressionTree(tokens);
     PrintExpressionTree(tree);
+    printf("\n");
     FreeExpressionTree(tree);
     DestroyTokenList(tokens);
 }

parser.c

@@ -1,5 +1,6 @@
 #include "parser.h"
 #include "expr.h"
+#include "token.h"
 #include <stdio.h>
 
 Expr* Expression(void);
@@ -15,6 +16,7 @@ int ParserAtEnd(void);
 Token* ParserPeek(void);
 Token* Previous(void);
 Token* AdvanceParser(void);
+void SynchronizeParser(void);
 
 const TokenList* ListOfTokens;
 int Current = 0;
@@ -117,25 +119,18 @@ Expr* Primary() {
     expr->type = LITERAL;
 
     if (Match(3, FALSE, TRUE, NIL)) {
-        expr->expression.Literal.type = ParserPeek();//CreateToken("false", FALSE);
+        expr->expression.Literal = ParserPeek();
         return expr;
     }
-    // if (SMatch(1, TRUE)) {
-    //     expr->expression.Literal.type = //CreateToken("true", TRUE);
-    //     return expr;
-    // }
-    // if (SMatch(1, NIL)) {
-    //     expr->expression.Literal.type = //CreateToken("nil", NIL);
-    //     return expr;
-    // }
 
     if (Match(2, Number, String)) {
-        expr->expression.Literal.type = Previous();
+        expr->expression.Literal = Previous();
         return expr;
     }
 
+    free(expr);
+
     if (Match(1, LParen)) {
-        free(expr);
         expr = Expression();
         
         Expr* temp = calloc(1, sizeof(Expr));
@@ -147,8 +142,7 @@ Expr* Primary() {
         return temp;
     }
 
-    free(expr);
-    printf("Failed to match Primary\n");
+    printf("Bad expression\n");
 
     return NULL;
 }
@@ -190,6 +184,30 @@ Token* AdvanceParser() {
     return Previous();
 }
 
+void SynchronizeParser(void) {
+    AdvanceParser();
+    //Discard tokens until we find a statement boundary, or at least something that looks like one.
+    while(!ParserAtEnd()) {
+        if (Previous()->type == Semicolon) return;
+
+        switch(ParserPeek()->type) {
+            case CLASS:
+            case FOR:
+            case FUN:
+            case IF:
+            case PRINT:
+            case RETURN:
+            case VAR:
+            case WHILE:
+                return;
+            default:
+            break;
+        }
+
+        AdvanceParser();
+    }
+}
+
 void PrintExpressionTree(const Expr* tree) {
     if (!tree) return;
     
@@ -209,7 +227,7 @@ void PrintExpressionTree(const Expr* tree) {
     else if (tree->type == GROUPING) {
         PrintExpressionTree(tree->expression.Grouping.expression);
     }
-    else if (tree->type == LITERAL) printf("%s", tree->expression.Literal.type->lexeme);
+    else if (tree->type == LITERAL) printf("%s", tree->expression.Literal->lexeme);
 }
 
 void FreeExpressionTree(Expr* tree) {

token.h

@@ -43,7 +43,6 @@ typedef struct {
     TokenType type;
     const char* lexeme;
     int line;
-    int length;
 } Token;
 
 extern KeyValuePair TokenTypeMappings[TOKENTYPE_MAPPINGS_COUNT];