#ifndef PGF_LEXER_H_
#define PGF_LEXER_H_

#include <gu/in.h>
#include <pgf/expr.h>

/// A single lexical token			      
typedef GuString PgfToken;
typedef GuSeq PgfTokens;  // -> PgfToken

typedef struct {
	prob_t prob;
	PgfCId cat;
	PgfToken tok;
} PgfTokenProb;

typedef struct {
	PgfToken (*read_token)();
	PgfToken tok;
} PgfLexer;

PgfLexer*
pgf_new_simple_lexer(GuIn *in, GuPool *pool);

PgfToken
pgf_lexer_read_token(PgfLexer *lexer, GuExn* err);

PgfToken
pgf_lexer_current_token(PgfLexer *lexer);

#endif // PGF_LEXER_H_