Accept tabs as being equivalent to eight spaces, but no mixing on a single line

README.md

@@ -141,13 +141,7 @@ Blocks, including function `def` blocks and control flow structures like `if` an
 
 You may indent blocks to whatever level you desire, so long as ordering remains consistent, though the recommendation indentation size is 4 spaces.
 
-Tabs are not valid as indentation and will be ignored. It is recommended that you use an editor which provides a clear visual distinction between tabs and spaces, such as [Bim](https://github.com/klange/bim).
-
-```py
-if False:
-	print("Oh no, that was a tab.")
-# → Oh no, that was a tab.
-```
+It is recommended that you use an editor which provides a clear visual distinction between tabs and spaces, such as [Bim](https://github.com/klange/bim).
 
 Blocks can also accept a single inline statement:
 

scanner.c

@@ -86,18 +86,19 @@ static void skipWhitespace() {
 }
 
 static KrkToken makeIndentation() {
+	char reject = (peek() == ' ') ? '\t' : ' ';
 	while (!isAtEnd() && (peek() == ' ' || peek() == '\t')) advance();
 	if (isAtEnd()) return makeToken(TOKEN_EOF);
-	if (peek() == '\n') {
-		/* Pretend we didn't see this line */
-		return makeToken(TOKEN_INDENTATION);
+	for (const char * start = scanner.start; start < scanner.cur; start++) {
+		if (*start == reject) return errorToken("Invalid mix of indentation.");
 	}
+	KrkToken out = makeToken(TOKEN_INDENTATION);
+	if (reject == ' ') out.length *= 8;
 	if (peek() == '#') {
-		KrkToken out = makeToken(TOKEN_INDENTATION);
+		/* Skip the entirety of the comment but not the line feed */
 		while (!isAtEnd() && peek() != '\n') advance();
-		return out;
 	}
-	return makeToken(TOKEN_INDENTATION);
+	return out;
 }
 
 static KrkToken string(char quoteMark) {

test/testLinesFromReadme.krk.expect

@@ -1,2 +1,2 @@
-960 lines
+954 lines
 ['', 'Kuroko is a bytecode-interpreted, dynamic, strongly-typed language with syntax similar to Python.', '', 'The bytecode VM / compiler is substantially based on Robert Nystrom\'s [_Crafting Interpreters_](https://craftinginterpreters.com/).']

test/testTabWidth.krk

@@ -0,0 +1,5 @@
+def foo():
+        print("Four spaces")
+	print("Four tabs")
+
+foo()

test/testTabWidth.krk.expect

@@ -0,0 +1,2 @@
+Four spaces
+Four tabs