From a0d5d62a34844ca665945d58f6776cc7a1124a05 Mon Sep 17 00:00:00 2001
From: Garritt McCune <glmccune@gmail.com>
Date: Mon, 3 Oct 2022 15:20:31 +0000
Subject: [PATCH] Fixed a bug in the Scanner when parsing a hex number, still
 not super robust but it'll work.

---
 src/scanner.c | 42 +++++++++++++++++++++++++++++++++++++++---
 1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/src/scanner.c b/src/scanner.c
index d85b34c..b28202f 100644
--- a/src/scanner.c
+++ b/src/scanner.c
@@ -1,6 +1,8 @@
 #include "../includes/scanner.h"
+#include <ctype.h>
 #include <stdlib.h>
 #include <string.h>
+#include <limits.h>
 
 const char* SourceCode;
 int Line = 1;
@@ -8,6 +10,7 @@ int Position = 0;
 int SourceLength = 0;
 int ScannerAtEnd(void);
 int IsPunctuation(char);
+int IsWhiteSpace(char);
 char PeekScanner(void);
 char PeekAheadScanner(void);
 void AdvanceScanner(void);
@@ -34,6 +37,8 @@ List* GenerateTokenList(const char* source) {
             case ' ':
             case '\r':
             case '\t':
+            case '\v':
+            case '\f':
                 AdvanceScanner();
                 break; //Ignore whitespace
             case '\n':
@@ -98,9 +103,21 @@ Token* ParseNumber(void) {
     while(!ScannerAtEnd() && isdigit(PeekScanner()))
         AdvanceScanner();
 
-    if (PeekScanner() == 'x' && isdigit(PeekAheadScanner())) {
-        AdvanceScanner(); //Consume the 'x'
-        while(!ScannerAtEnd() && isdigit(PeekScanner())) AdvanceScanner();
+    if (tolower(PeekScanner()) == 'x') {
+        char ahead = tolower(PeekAheadScanner());
+
+        if ((ahead >= 'a' && ahead <= 'f') || isdigit(ahead)) {
+            AdvanceScanner(); //Consume the 'x'
+
+            while(!ScannerAtEnd() && PeekScanner() != '\n' && !IsWhiteSpace(PeekScanner())) {
+                if (isdigit(PeekScanner())) { 
+                    AdvanceScanner();
+                    continue;
+                }
+
+                if (tolower(PeekScanner()) >= 'a' && tolower(PeekScanner()) <= 'f') AdvanceScanner();
+            }
+        }
     }
 
     int length = Position - start;
@@ -119,6 +136,12 @@ Token* ParseNumber(void) {
     Token* token = CreateToken(Line, NumberClass);
 
     token->Value.Number = strtol(lexeme, NULL, 0);
+
+    if (errno != 0) {
+        fprintf(stderr, "[Error] Line %d: Invalid number detected. %s.\n", Line, strerror(errno));
+        exit(1);
+    }
+
     token->Lemexe = lexeme;
 
     return token;
@@ -285,6 +308,19 @@ int IsPunctuation(char c) {
     }
 }
 
+int IsWhiteSpace(char c) {
+    switch(c) {
+        case ' ':
+        case '\t':
+        case '\v':
+        case '\f':
+        case '\r':
+            return 1;
+        default:
+            return 0;
+    }
+}
+
 Token* ParsePunctuation(char c) {
     TokenPunctuation punctuation;