Added lexer, implemented tests build system

tests/cases/test_lexer.c

@@ -0,0 +1,47 @@
+#include "toy_lexer.h"
+#include "toy_console_colors.h"
+
+#include <stdio.h>
+#include <string.h>
+
+int main() {
+	{
+		//source code sample to operate on
+		char* source = "print null;";
+
+		//test the lexer
+		Toy_Lexer lexer;
+		Toy_bindLexer(&lexer, source);
+
+		//get each token
+		Toy_Token print = Toy_private_scanLexer(&lexer);
+		Toy_Token null = Toy_private_scanLexer(&lexer);
+		Toy_Token semi = Toy_private_scanLexer(&lexer);
+		Toy_Token eof = Toy_private_scanLexer(&lexer);
+
+		//test each token is correct
+		if (strncmp(print.lexeme, "print", print.length)) {
+			fprintf(stderr, TOY_CC_ERROR "ERROR: print lexeme is wrong: %s" TOY_CC_RESET, print.lexeme);
+			return -1;
+		}
+
+
+		if (strncmp(null.lexeme, "null", null.length)) {
+			fprintf(stderr, TOY_CC_ERROR "ERROR: null lexeme is wrong: %s" TOY_CC_RESET, null.lexeme);
+			return -1;
+		}
+
+		if (strncmp(semi.lexeme, ";", semi.length)) {
+			fprintf(stderr, TOY_CC_ERROR "ERROR: semicolon lexeme is wrong: %s" TOY_CC_RESET, semi.lexeme);
+			return -1;
+		}
+
+		if (eof.type != TOY_TOKEN_EOF) {
+			fprintf(stderr, TOY_CC_ERROR "ERROR: Failed to find EOF token" TOY_CC_RESET);
+			return -1;
+		}
+	}
+
+	printf(TOY_CC_NOTICE "All good\n" TOY_CC_RESET);
+	return 0;
+}