Further refactoring done. The Parser runs without crashing, however it's output is still to be checked and verified.

scanner.c

@@ -8,13 +8,13 @@ int current; //points to the character currently being considered.
 int length;
 int line = 1;
 
-const char* SAdvance(void);
-int SIsAtEnd(void);
+const char* AdvanceScanner(void);
+int ScannerAtEnd(void);
 void ScanToken(TokenList*);
 TokenList* CreateList(void);
 int AddToTokenList(Token*, TokenList*);
-int SMatch(char);
-char SPeek(void);
+int ScannerMatch(char);
+char ScannerPeek(void);
 char PeekNext(void);
 void ParseString(TokenList *);
 void ParseNumber(TokenList *);
@@ -32,7 +32,7 @@ TokenList* ScanTokens(const char* source) {
 
     TokenList* tokens = CreateList();
 
-    while(!SIsAtEnd()) {
+    while(!ScannerAtEnd()) {
         start = current;
         ScanToken(tokens);
     }
@@ -68,11 +68,7 @@ void DestroyTokenList(TokenList* list) {
     if (!list) return;
 
     for(int i = 0; i < list->size; i++) {
-        //Only free objects that required allocation, i.e. not in the TokenTypeMappings
-        if (list->tokens[i]->type == String || list->tokens[i]->type == Number || list->tokens[i]->type == Identifier)
-            free((void *) list->tokens[i]->lexeme);
-            
-        free(list->tokens[i]);
+        FreeToken(list->tokens[i]);
     }
 
     free(list->tokens);
@@ -102,7 +98,7 @@ int AddToTokenList(Token* token, TokenList* list) {
 }
 
 void ScanToken(TokenList* tokens) {
-    const char* c = SAdvance();
+    const char* c = AdvanceScanner();
     
     switch (*c) {
     case '(':
@@ -136,23 +132,23 @@ void ScanToken(TokenList* tokens) {
         AddToTokenList(CreateToken(NULL, line, Star), tokens);
         break;
     case '!':
-        if (SMatch('=')) AddToTokenList(CreateToken(NULL, line, Bang_Equal), tokens);
+        if (ScannerMatch('=')) AddToTokenList(CreateToken(NULL, line, Bang_Equal), tokens);
         else AddToTokenList(CreateToken(NULL, line, Bang), tokens);
         break;
     case '=':
-        if (SMatch('=')) AddToTokenList(CreateToken(NULL, line, Equal_Equal), tokens);
+        if (ScannerMatch('=')) AddToTokenList(CreateToken(NULL, line, Equal_Equal), tokens);
         else AddToTokenList(CreateToken(NULL, line, Equal), tokens);
         break;
     case '<':
-        if (SMatch('=')) AddToTokenList(CreateToken(NULL, line, Less_Equal), tokens);
+        if (ScannerMatch('=')) AddToTokenList(CreateToken(NULL, line, Less_Equal), tokens);
         else AddToTokenList(CreateToken(NULL, line, Less), tokens);
         break;
     case '>':
-        if (SMatch('=')) AddToTokenList(CreateToken(NULL, line, Greater_Equal), tokens);
+        if (ScannerMatch('=')) AddToTokenList(CreateToken(NULL, line, Greater_Equal), tokens);
         else AddToTokenList(CreateToken(NULL, line, Greater), tokens);
         break;
     case '/':
-        if (SMatch('/')) while(SPeek() != '\n' && !SIsAtEnd()) { SAdvance(); }
+        if (ScannerMatch('/')) while(ScannerPeek() != '\n' && !ScannerAtEnd()) { AdvanceScanner(); }
         else AddToTokenList(CreateToken(NULL, line, Slash), tokens);
 
         break;
@@ -180,16 +176,16 @@ void ScanToken(TokenList* tokens) {
     }
 }
 
-int SIsAtEnd() {
+int ScannerAtEnd() {
     return current >= length;
 }
 
-const char* SAdvance() {
+const char* AdvanceScanner() {
     return &source_code[current++];
 }
 
-int SMatch(char expected) {
-    if (SIsAtEnd()) return 0;
+int ScannerMatch(char expected) {
+    if (ScannerAtEnd()) return 0;
     if (source_code[current] != expected) return 0;
 
     current++;
@@ -197,8 +193,8 @@ int SMatch(char expected) {
     return 1;
 }
 
-char SPeek() {
-    if (SIsAtEnd()) return '\0';
+char ScannerPeek() {
+    if (ScannerAtEnd()) return '\0';
 
     return source_code[current];
 }
@@ -206,12 +202,12 @@ char SPeek() {
 void ParseString(TokenList *list) {
     start = current;    //The start is currently pointing to the first double quote so we need to move it
                         //to the next (first character) of the string literal.
-    while(SPeek() != '"' && !SIsAtEnd()) {
-        if (SPeek() == '\n') line++;
-        SAdvance();
+    while(ScannerPeek() != '"' && !ScannerAtEnd()) {
+        if (ScannerPeek() == '\n') line++;
+        AdvanceScanner();
     }
 
-    if (SIsAtEnd()) {
+    if (ScannerAtEnd()) {
         fprintf(stderr, "Unterminated string.\n");
         return;
     }
@@ -227,16 +223,16 @@ void ParseString(TokenList *list) {
     
     AddToTokenList(CreateToken(lexeme, line, String), list);
 
-    SAdvance(); // The closing ".
+    AdvanceScanner(); // The closing ".
 }
 
 void ParseNumber(TokenList* list) {
-    while(isdigit(SPeek())) SAdvance();
+    while(isdigit(ScannerPeek())) AdvanceScanner();
 
-    if (SPeek() == '.' && isdigit(PeekNext())) {
-        SAdvance();
+    if (ScannerPeek() == '.' && isdigit(PeekNext())) {
+        AdvanceScanner();
 
-        while(isdigit(SPeek())) SAdvance();
+        while(isdigit(ScannerPeek())) AdvanceScanner();
     }
 
     char* lexeme = calloc(current - start + 2, sizeof(char));
@@ -258,12 +254,12 @@ char PeekNext() {
 }
 
 void ParseIdentifier(TokenList * list) {
-    while(IsAlpha(SPeek())) SAdvance();
+    while(IsAlpha(ScannerPeek())) AdvanceScanner();
 
     char* lexeme = calloc(current - start + 2, sizeof(char));
     
     snprintf(lexeme, current - start + 1, "%s", &source_code[start]);
-    printf("%s\n", lexeme);
+    
     KeyValuePair* result = Get(lexeme);
 
     if (result) {