1 files changed, 55 insertions, 0 deletions
diff --git a/masm/lex.h b/masm/lex.h
new file mode 100644
index 0000000..f1c482a
--- /dev/null
+++ b/masm/lex.h
@@ -0,0 +1,55 @@
+/* Copyright (c) 2024 Freya Murphy */
+
+#ifndef __LEX_H__
+#define __LEX_H__
+
+#include <mlimits.h>
+#include <stdio.h>
+#include <stdint.h>
+
+struct lexer {
+	FILE *file;
+	int peek;
+	int x;
+	int y;
+};
+
+enum token_type {
+	TOK_IDENT,
+	TOK_REG,
+	TOK_LABEL,
+	TOK_STRING,
+	TOK_COMMA,
+	TOK_EQUAL,
+	TOK_LPAREN,
+	TOK_RPAREN,
+	TOK_NUMBER,
+	TOK_EOF,
+	TOK_NL,
+	TOK_DIRECTIVE,
+};
+
+struct token {
+	enum token_type type;
+	union {
+		int64_t number;
+		char text[MAX_LEX_LENGTH];
+	};
+	int x;
+	int y;
+};
+
+/* initalize a lexer */
+int lexer_init(const char *file, struct lexer *lexer);
+
+/* free the lxer */
+int lexer_free(struct lexer *lexer);
+
+/* lexes the next token, returns M_ERROR on error,
+ * and TOK_EOF on EOF */
+int lexer_next(struct lexer *lexer, struct token *token);
+
+/* token type to string */
+char *token_str(enum token_type);
+
+#endif /* __LEX_H__ */