Updated the scanner to parse registers, assembly keywords and identifiers.

src/scanner.c

@@ -1,9 +1,11 @@
 #include "../includes/scanner.h"
+#include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 const char* SourceCode;
+int Line = 0;
 int Position = 0;
 int SourceLength = 0;
 int ScannerAtEnd(void);
@@ -12,6 +14,8 @@ char AdvanceScanner(void);
 Token* ParseString(void);
 Token* ParseDirective(void);
 Token* ParseIdentifier(void);
+Token* ParseNumber(void);
+void IgnoreLine(void);
 
 List* GenerateTokenList(const char* source) {
     List* tokens = CreateList();
@@ -23,15 +27,20 @@ List* GenerateTokenList(const char* source) {
     SourceLength = strlen(source);
 
     for(int i = 0; i < SourceLength; i++) {
-        char c = AdvanceScanner();
+        char c = PeekScanner();
+        
         switch(c) {
             case ' ':
             case '\r':
             case '\t':
+                AdvanceScanner();
                 break; //Ignore whitespace
+            case '\n':
+                AdvanceScanner();
+                Line++;
+                break;
             case ';':
-                while(!ScannerAtEnd() && PeekScanner() != '\n') AdvanceScanner();
-
+                IgnoreLine();
                 break;
             case '.': //directive like ".org" or ".db"
                 token = ParseDirective();
@@ -42,15 +51,15 @@ List* GenerateTokenList(const char* source) {
                 if (token) AddListItem(token, sizeof(Token), tokens);
                 break;
             case ',':
+                AdvanceScanner();
                 AddListItem(CreateToken(COMMA, ","), sizeof(Token), tokens);
                 break;
             default:
-                // if (c >= '0' && c <= '9') {
-                //     //Number
-
-                //     break;
-                // }
+                if (c >= '0' && c <= '9') {
+                    ParseNumber();
 
+                    break;
+                }
                 token = ParseIdentifier();
 
                 if (token) AddListItem(token, sizeof(Token), tokens);
@@ -64,31 +73,66 @@ List* GenerateTokenList(const char* source) {
     return tokens;
 }
 
-Token* ParseDirective(void) {
-    char directive[10] = { 0 };
-    int length = 0;
+Token* ParseNumber(void) {
+    int start = Position;
 
-    for(; length < sizeof directive - 1; length++) {
-        if (PeekScanner() == ' ') break;
+    while(!ScannerAtEnd() && PeekScanner() >= '0' && PeekScanner() <= '9')
+        AdvanceScanner();
 
-        directive[length] = AdvanceScanner();
-    }
+    char* lexeme = calloc(Position - start + 1, sizeof(char));
 
-    if (strcmp(directive, ".db") == 0) {
-        return CreateToken(DB, ".db");
-    } else if (strcmp(directive, ".org") == 0) {
-        //fprintf(stderr, "[Warning] Org is not a supported directive.\n");
+    if (!lexeme) {
+        fprintf(stderr, "Failed to calloc space for number.\n");
         return NULL;
     }
 
-    fprintf(stderr, "[Error] Unknown assembler directive '%s'\n", directive);
-    //Ignore the line 
-    while(PeekScanner() != '\n') AdvanceScanner();
+    memcpy(lexeme, &SourceCode[start], Position - start);
 
+    return CreateToken(NUMBER, lexeme);
+}
+
+Token* ParseDirective(void) {
+    int start = Position;
+
+    while(!ScannerAtEnd() && PeekScanner() != ' ' && PeekScanner() != '\n') AdvanceScanner();
+        
+    if (start == Position) return NULL;
+
+    char* directive = calloc(Position - start + 1, sizeof(char));
+
+    if (!directive) {
+        fprintf(stderr, "Failed to calloc for the assmebler directive.\n");
+        return NULL;
+    }
+
+    memcpy(directive, &SourceCode[start], Position - start);
+
+    if (strcmp(directive, ".db") == 0) {
+        return CreateToken(DB, directive);
+    } 
+    // else if (strcmp(directive, ".org") == 0) {
+    //     fprintf(stderr, "[Warning] Org is not a supported directive.\n");
+    //     IgnoreLine();
+    //     return NULL;
+    // }
+
+    fprintf(stderr, "[Error] Unknown assembler directive '%s'\n", directive);
+
+    free(directive);
+    
+    //Ignore the line 
+    IgnoreLine();
+    
     return NULL;
 }
 
+void IgnoreLine(void) {
+    while(!ScannerAtEnd() && PeekScanner() != '\n') AdvanceScanner();
+}
+
 Token* ParseString(void) {
+    AdvanceScanner(); //Consume the first double quote.
+
     int start = Position;
 
     while(!ScannerAtEnd() && PeekScanner() != '"') {
@@ -96,9 +140,9 @@ Token* ParseString(void) {
     }
 
     char* lexeme = calloc(Position - start, sizeof(char));
-    memccpy(lexeme, &SourceCode[start], sizeof(char), Position - start);
+    memcpy(lexeme, &SourceCode[start], Position - start);
 
-    AdvanceScanner();
+    AdvanceScanner(); //Consume the trailing double quote.
 
     Token* token = CreateToken(STRING, lexeme);
 
@@ -108,20 +152,24 @@ Token* ParseString(void) {
 Token* ParseIdentifier(void) {
     int start = Position;
 
-    while(!ScannerAtEnd() && PeekScanner() != ' ' && PeekScanner() != '\n') {
+    while(!ScannerAtEnd() && PeekScanner() != ',' && PeekScanner() != ' ' && PeekScanner() != '\n') {
         AdvanceScanner();
     }
 
     if (Position - start == 0) return NULL;
     
     char* lexeme = calloc(Position - start, sizeof(char));
-    memccpy(lexeme, &SourceCode[start], sizeof(char), Position - start);
+    TokenType type;
+    memcpy(lexeme, &SourceCode[start], Position - start);
+
+    if (IsOpcode(lexeme, &type)) return CreateToken(type, lexeme);
+    if (IsRegister(lexeme, &type)) return CreateToken(type, lexeme);
 
     return CreateToken(IDENTIFIER, lexeme);
 }
 
 char PeekScanner(void) {
-    if (Position > SourceLength) return '\0';
+    if (Position >= SourceLength) return '\0';
 
     return SourceCode[Position];
 }