mips/masm/lex.h

/* 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;
};

struct lexer_state {
	long offset;
	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);

/* save the state of a lexer */
void lexer_save(struct lexer *lexer, struct lexer_state *state);

/* load a different state into a lexer */
void lexer_load(struct lexer *lexer, const struct lexer_state *state);

#endif /* __LEX_H__ */