Touched up the Scanner. Refactored the Parser some more, this time it's able to be run on simple expressions. String concatenation can be performed by the Parser however, numbers and Booleans are not being stored correctly in the Object structures.

.gitignore

@@ -1,4 +1,3 @@
 clox
 *.lox
 obj/
-bin/

Makefile

@@ -1,37 +1,17 @@
 CC = gcc
-CFLAGS=-g -Wall -DDEBUG
-SRCDIR=src
-OBJDIR=obj
-SRCS=$(wildcard $(SRCDIR)/*.c)
-# Substitute all .c with .o from SRCS
-OBJS=$(patsubst $(SRCDIR)/%.c, $(OBJDIR)/%.o, $(SRCS))
+SOURCEFILES := $(wildcard *.c)
 
-BINDIR=bin
-BIN=$(BINDIR)/clox
+SOURCE := $(wildcard *.c)
 
-all: $(BIN)
-
-release: CFLAGS=-Wall -O2
-release: clean
-release: $(BIN)
-
-$(BIN): $(OBJS) $(BINDIR)
-	$(CC) $(CFLAGS) $(OBJS) -o $@
-
-$(OBJDIR)/%.o: $(SRCDIR)/%.c $(OBJDIR)
-	$(CC) $(CFLAGS) -c $< -o $@
-
-$(BINDIR):
-	mkdir $@
-
-$(OBJDIR):
-	mkdir $@
+$(SOURCE:.c=.o): $(SOURCE)
+	@mkdir -p obj
+	$(CC) $^ -o obj/clox
 
 .PHONY: clean
 .PHONY: test
 
 clean:
-	rm -rf $(BINDIR)/* $(OBJDIR)/*
+	rm -r obj
 
 test:
-	$(BIN) test.lox
+	./obj/clox test.lox

expr.c

@@ -0,0 +1,18 @@
+#include "expr.h"
+
+char* Parenthesize(char*, int, ...);
+
+void VisitBinary(struct binary expr) {
+
+}
+
+void VisitGrouping(struct grouping);
+void VisitLiteral(Token);
+void VisitUnary(struct unary);
+
+char* Parenthesize(char* operator, int count, ...) {
+    va_list list;
+    va_start(list, count);
+
+    va_arg(list, Expr);
+}

expr.h

@@ -40,9 +40,9 @@ struct Expr {
     } expression;
 };
 
-// void VisitBinary(struct binary);
-// void VisitGrouping(struct grouping);
-// void VisitLiteral(Token);
-// void VisitUnary(struct unary);
+void VisitBinary(struct binary);
+void VisitGrouping(struct grouping);
+void VisitLiteral(Token);
+void VisitUnary(struct unary);
 
 #endif

interpreter.c

@@ -14,7 +14,6 @@ Object* VisitBinaryExpression(Expr*);
 int IsTruthy(Object*);
 int IsEqual(Object*, Object*);
 int ConcatStringObject(Object*, const Object*);
-void CheckNumberOperands(TokenType, int, ...);
 void PrintObject(Object*);
 
 void PrintObject(Object* o) {
@@ -54,6 +53,7 @@ void Interpret(Expr* exp) {
 }
 
 Object* VisitLiteralExpression(Expr* expr) {
+    printf("Literal: %p\n", (double *) expr->expression.Literal->literal);
     return CreateObject(expr->expression.Literal->literal, expr->expression.Literal->type);
 }
 
@@ -66,65 +66,59 @@ Object* VisitGroupingExpression(Expr* expression) {
 Object* VisitBinaryExpression(Expr* expression) {
     Object* left = Evaluate(expression->expression.Binary.left);
     Object* right = Evaluate(expression->expression.Binary.right);
+    PrintObject(left);
+    PrintObject(right);
     double computed_value;
 
     switch(expression->expression.Binary.op->type) {
         case Greater:
-        CheckNumberOperands(expression->expression.Binary.op->type, 2, left, right);
         computed_value = left->value.number > right->value.number;
         FreeObject(left);
         FreeObject(right);
         return CreateObject(&computed_value, TRUE);
         //return left > right;
         case Greater_Equal:
-        CheckNumberOperands(expression->expression.Binary.op->type, 2, left, right);
         computed_value = left->value.number >= right->value.number;
         FreeObject(left);
         FreeObject(right);
         return CreateObject(&computed_value, TRUE);
         //return left >= right;
         case Less:
-        CheckNumberOperands(expression->expression.Binary.op->type, 2, left, right);
         computed_value = left->value.number < right->value.number;
         FreeObject(left);
         FreeObject(right);
         return CreateObject(&computed_value, TRUE);
         //return left < right;
         case Less_Equal:
-        CheckNumberOperands(expression->expression.Binary.op->type, 2, left, right);
         computed_value = left->value.number <= right->value.number;
         FreeObject(left);
         FreeObject(right);
         return CreateObject(&computed_value, TRUE);
         //return left <= right;
         case Bang_Equal:
-        CheckNumberOperands(expression->expression.Binary.op->type, 2, left, right);
         computed_value = !IsEqual(left, right);
         FreeObject(left);
         FreeObject(right);
         return CreateObject(&computed_value, TRUE);
         //return !IsEqual(left, right);
         case Equal_Equal:
-        CheckNumberOperands(expression->expression.Binary.op->type, 2, left, right);
         computed_value = IsEqual(left, right);
         FreeObject(left);
         FreeObject(right);
         return CreateObject(&computed_value, TRUE);
         //return IsEqual(left, right);
         case Minus:
-            CheckNumberOperands(expression->expression.Binary.op->type, 2, left, right);
             left->value.number -= right->value.number;
             FreeObject(right);
             return left;
         //return left - right;
         case Slash:
-            CheckNumberOperands(expression->expression.Binary.op->type, 2, left, right);
             left->value.number /= right->value.number;
             FreeObject(right);
             return left;
         //return *((double*)left) / *((double*)right);
         case Star:
-            CheckNumberOperands(expression->expression.Binary.op->type, 2, left, right);
+            printf("%f * %f = %f\n", left->value.number, right->value.number, left->value.number * right->value.number);
             left->value.number *= right->value.number;
             FreeObject(right);
             return left;
@@ -165,7 +159,6 @@ Object* VisitUnaryExpression(Expr* expression) {
 
     switch (expression->expression.Unary.op->type) {
         case Minus:
-        CheckNumberOperands(expression->expression.Unary.op->type, 1, right);//This needs to "throw" if the function fails.
         computed_value = -right->value.number;
         FreeObject(right);
         c = CreateObject(&computed_value, Number);
@@ -229,16 +222,11 @@ Object* CreateObject(const void* value, TokenType type) {
         break;
         default:
         if (value) {
-            unsigned int length = strlen(value);
+            int length = strlen(value);
             object->instance = INS_STRING;
             object->value.string = calloc(length + 1, sizeof(char));
-
-            if (!object->value.string) {
-                fprintf(stderr, "Faild to calloc %u bytes for a new string Object. %s.\n", length + 1, strerror(errno));
-                return NULL;
-            }
             
-            memcpy(object->value.string, value, length);
+            strncpy(object->value.string, value, length);
         } else object->instance = INS_NULL; //TODO: this is most likely an error, but we'll ignore that for now.
     }
 
@@ -294,19 +282,4 @@ int IsEqual(Object* a, Object* b) {
     }
     
     return 0;
-}
-
-void CheckNumberOperands(TokenType operator, int operandCount, ...) {
-    va_list list;
-    va_start(list, operandCount);
-
-    for(int i = 0; i < operandCount; i++) {
-        Object* operand = va_arg(list, Object*);
-        if (operand->instance != INS_DOUBLE) {
-            va_end(list);
-            return; //TODO: "throw" runtime error "Operand must be a number."
-        }
-    }
-
-    va_end(list);
 }

lox.c

@@ -39,9 +39,8 @@ void RunFile(const char* path) {
     char* contents = GetFileContents(path);
     TokenList* tokens = ScanTokens(contents);
     free(contents);
-    printf("TOKENS:\n");
     Print(tokens);
-    printf("EXPRESSION TREE:\n");
+    printf("TREE:\n");
     Expr* tree = GenerateExpressionTree(tokens);
     PrintExpressionTree(tree);
     printf("\n");

parser.c

@@ -1,6 +1,5 @@
 #include "parser.h"
 #include "expr.h"
-#include "statement.h"
 #include "token.h"
 #include <stdio.h>
 
@@ -11,9 +10,6 @@ Expr* Term(void);
 Expr* Factor(void);
 Expr* Unary(void);
 Expr* Primary(void);
-Stmt* Statement(void);
-Stmt* PrintStatement(void);
-Stmt* ExpressionStatement(void);
 int Match(int, ...);
 int Check(TokenType);
 int ParserAtEnd(void);
@@ -36,34 +32,6 @@ Expr* Expression() {
     return Equality();
 }
 
-Stmt* Statement(void) {
-    if (Match(1, PRINT)) return PrintStatement();
-
-    return ExpressionStatement();
-}
-
-Stmt* PrintStatement(void) {
-    Expr* value = Expression();
-
-    if (!Match(1, Semicolon)) fprintf(stderr, "Expected ';' after value\n");
-
-    AdvanceParser();
-
-    return CreateStatement(value, STMT_Print);
-}
-
-Stmt* ExpressionStatement(void) {
-    Expr* expr = Expression();
-
-    if (!Match(1, Semicolon)) fprintf(stderr, "Expected ';' after expression\n");
-
-    AdvanceParser();
-
-    return CreateStatement(expr, STMT_Expression);
-}
-
-Stmt* ExpressionStatement(void);
-
 Expr* Equality() {
     Expr* expr = Comparison();
 
@@ -178,7 +146,7 @@ Expr* Primary() {
         return temp;
     }
 
-    fprintf(stderr, "Bad expression, this should be unreachable.\n");
+    printf("Bad expression\n");
 
     return NULL;
 }
@@ -189,14 +157,11 @@ int Match(int count, ...) {
 
     for(int i = 0; i < count; i++) {
         if(Check(va_arg(list, TokenType))) {
-            va_end(list);
             AdvanceParser();
             return 1;
         }
     }
 
-    va_end(list);
-
     return 0;
 }
 

parser.h

@@ -4,7 +4,6 @@
 #include "expr.h"
 #include "scanner.h"
 #include "token.h"
-#include "statement.h"
 #include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>

scanner.c

@@ -1,6 +1,5 @@
 #include "scanner.h"
 #include "token.h"
-#include <string.h>
 
 const char* source_code;
 //Start and Current hold the offsets that index into the string source_code.
@@ -246,17 +245,9 @@ void ParseNumber(TokenList* list) {
     }
 
     snprintf(lexeme, current - start, "%s", &source_code[start]);
-    double* value = calloc(1, sizeof(double));
-
-    if (!value) {
-        fprintf(stderr, "Failed to calloc for number value. %s\n", strerror(errno));
-        free(lexeme);
-        return;
-    }
-
-    *value = atof(lexeme);
+    double value = atof(lexeme); //Will this reference become stale on return?
     
-    AddToTokenList(CreateToken(lexeme, value, line, Number), list);
+    AddToTokenList(CreateToken(lexeme, &value, line, Number), list);
 }
 
 char PeekNext() {

src/statement.c

@@ -1,21 +0,0 @@
-#include "statement.h"
-
-Stmt* CreateStatement(Expr* expression, StatementType type) {
-    Stmt* stmt = calloc(1, sizeof(Stmt));
-
-    if (!stmt) {
-        fprintf(stderr, "Failed to calloc space for Statement. %s.\n", strerror(errno));
-        return NULL;
-    }
-
-    stmt->expression = expression;
-    stmt->type = type;
-
-    return stmt;
-}
-
-void FreeStatement(Stmt* stmt) {
-    if (!stmt) return;
-    
-    free(stmt);
-}

src/statement.h

@@ -1,22 +0,0 @@
-#ifndef STATEMENT_H
-#define STATEMENT_H
-
-#include "expr.h"
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-
-typedef enum {
-    STMT_Expression,
-    STMT_Print
-} StatementType;
-
-typedef struct stmt {
-    StatementType type;
-    Expr* expression;
-} Stmt;
-
-Stmt* CreateStatement(Expr*, StatementType);
-void FreeStatement(Stmt*);
-
-#endif

token.c

@@ -33,7 +33,7 @@ Token* CreateToken(const char* lexeme, void* literal, int line, TokenType type)
         const char* mapping_result = GetLexemeMapping(type);
         
         if (!mapping_result) {
-            fprintf(stderr, "Failed to get the mapping for TokenType value %d.\n", type);
+            fprintf(stderr, "Failed to get the mapping for %s\n", lexeme);
             free(token);
             return NULL;
         }