Added StringVAppend to append via a format and va_args list.

includes/pstring.h

@@ -3,11 +3,14 @@
 
 #include <string.h>
 #include <stdlib.h>
+#include <stdarg.h>
+#include <stdio.h>
 
 typedef struct pstring PString;
 
 PString* CreateString(void);
 void StringAppend(const char* text, PString* string);
+void StringVAppend(PString* string, const char* format, ...);
 void StringFree(PString* string);
 void StringTruncate(PString* string);
 char* StringToCString(PString* string);

src/parser.c

@@ -2,7 +2,7 @@
 #include "../includes/pstring.h"
 #include <stdarg.h>
 
-#define ParserExpects(...) ParserExpectList(sizeof((TokenType[]){__VA_ARGS__})/sizeof(TokenType), __VA_ARGS__)
+#define ParserExpects(...) ParserExpectList(sizeof((TokenType[]){__VA_ARGS__}) / sizeof(TokenType), __VA_ARGS__)
 
 static Array* Tokens;
 
@@ -23,8 +23,7 @@ Token* ParserExpect(TokenType type);
 Token* ParserExpectList(int count, ...);
 Token* ParserWant(TokenType type);
 void ParserExpectLineEnd(void);
-//Some more on atrributes:
+//Some more on attributes: https://gcc.gnu.org/onlinedocs/gcc-3.1/gcc/Function-Attributes.html#Function%20Attributes
-//https://gcc.gnu.org/onlinedocs/gcc-3.1/gcc/Function-Attributes.html#Function%20Attributes
 void ParserSync(char* format, ...) __attribute__ ((noreturn));
 void ParserSyncExpect(TokenType expected, TokenType found) __attribute__ ((noreturn));
 void ParserSyncMessage(char* message) __attribute__ ((noreturn));
@@ -214,15 +213,17 @@ Token* ParserExpectList(int count, ...) {
 
         //Are we at the end?
         if (i + 1 >= count) {
-            StringAppend("or ", MessageString);
+            StringVAppend(MessageString, "or %s", buffer);
-            StringAppend(buffer, MessageString);
         } 
         else {
-            StringAppend(buffer, MessageString);
+            StringVAppend(MessageString, "%s, ", buffer);
-            StringAppend(", ", MessageString);
         }
     }
 
+    TokenTypeStringify(token->Type, buffer);
+
+    StringVAppend(MessageString, " but got %s.", buffer);
+
     ParserSyncMessage(StringToCString(MessageString));
 }
 

src/pstring.c

@@ -1,6 +1,6 @@
 #include "../includes/pstring.h"
 
-#define DEFUALT_SSTRING_SIZE 64
+#define DEFUALT_PSTRING_SIZE 64
 
 struct pstring {
     char* Buffer;
@@ -11,8 +11,8 @@ struct pstring {
 PString* CreateString(void) {
     PString* string = calloc(1, sizeof(PString));
 
-    string->Buffer = calloc(DEFUALT_SSTRING_SIZE, sizeof(char));
+    string->Buffer = calloc(DEFUALT_PSTRING_SIZE, sizeof(char));
-    string->Capacity = DEFUALT_SSTRING_SIZE;
+    string->Capacity = DEFUALT_PSTRING_SIZE;
 
     return string;
 }
@@ -40,6 +40,27 @@ void StringAppend(const char* text, PString* string) {
     string->Buffer[string->Length] = '\0';
 }
 
+void StringVAppend(PString* string, const char* format, ...) {
+    if (!string) return;
+
+    va_list args;
+    va_start(args, format);
+
+    int bytes = vsnprintf(NULL, 0, format, args) + 1;
+
+    va_end(args);
+
+    StringResize(bytes, string);
+
+    va_start(args, format);
+
+    (void) vsnprintf(&string->Buffer[string->Length], bytes, format, args);
+
+    va_end(args);
+
+    string->Length += bytes - 1; //Make sure Length points at the 'NUL' byte placed at the end.
+}
+
 void StringFree(PString* string) {
     if (!string) return;