update

Exercise 3/Lexer.c

@@ -9,27 +9,39 @@ int start(char* src) {
     return _STOP_;                          // stopping the state machine in any other case
 }
 
-int getNextCharacter(char* pos) {
-    if (isLetter(*pos)) {
-        return _READ_IDENTIFIER_;           // continues to read the identifier
-    }
+int getNextCharacter(char** ptr_current) {
+    char* pos = *ptr_current;
+    while(isWhiteSpace(*pos)) pos++;
+    if (isLetter(*pos)) return _READ_IDENTIFIER_;
+    if (isNum(*pos)) return _READ_NUM_LIT_;
+    if (isOperator(*pos)) return _READ_OPERATOR_;
     return _STOP_;                          // stopping the state machine in any other case
 }
 
-int readIdentifier(char* src) {
-    return _STOP_;                      // placeholder
+int readIdentifier(char** ptr_current) {
+    char* pos = *ptr_current;
+    printf("%c - Identifier\n", *pos);
+    pos++;
+    *ptr_current = pos;
+    return _GET_NEXT_CHARACTER_;
 }
 
-int readNumLit(char* src) {
-    return _STOP_;                      // placeholder
+int readNumLit(char** ptr_current) {
+    char* pos = *ptr_current;
+    printf("%c - Number\n", *pos);
+    return _GET_NEXT_CHARACTER_;
 }
 
-int readOperator(char* src) {
-    return _STOP_;                      // placeholder
+int readOperator(char** ptr_current) {
+    char* pos = *ptr_current;
+    printf("%c - Operator\n", *pos);
+    return _GET_NEXT_CHARACTER_;
 }
 
-int readPunctuation(char* src) {
-    return _STOP_;                      // placeholder
+int readPunctuation(char** ptr_current) {
+    char* pos = *ptr_current;
+    printf("%c - Punctuation\n", *pos);
+    return _GET_NEXT_CHARACTER_;
 }
 
 int isLetter(char in) {
@@ -45,3 +57,32 @@ int isLetter(char in) {
     }
     return 0;               // returning 0 if it's no letter
 }
+
+int isWhiteSpace(char in) {
+    if (in == ' ' || in == '\n') return 1;
+    return 0;
+}
+
+int isNum(char in) {
+    if (in >= '0' && in <= 0) return 1;
+    return 0;
+}
+
+int isOperator(char in) {
+    switch(in) {
+        case '=':
+            break;
+        case '*':
+            break;
+        case '+':
+            break;
+        default:
+            return 0;
+    }
+    return 1;
+}
+
+int isPunctuation(char in) {
+    if (in == ';') return 1;
+    return 0;
+}