89 lines
4.1 KiB
OCaml
89 lines
4.1 KiB
OCaml
(***********************************************************************)
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(* *)
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(* Objective Caml *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1996 Institut National de Recherche en Informatique et *)
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(* Automatique. Distributed only by permission. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(* Module [Lexing]: the run-time library for lexers generated by [camllex] *)
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(*** Lexer buffers *)
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type lexbuf =
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{ refill_buff : lexbuf -> unit;
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mutable lex_buffer : string;
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mutable lex_buffer_len : int;
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mutable lex_abs_pos : int;
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mutable lex_start_pos : int;
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mutable lex_curr_pos : int;
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mutable lex_last_pos : int;
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mutable lex_saved_state : int;
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mutable lex_last_action : int }
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(* The type of lexer buffers. A lexer buffer is the argument passed
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to the scanning functions defined by the generated scanners.
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The lexer buffer holds the current state of the scanner, plus
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a function to refill the buffer from the input. *)
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val from_channel : in_channel -> lexbuf
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(* Create a lexer buffer on the given input channel.
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[Lexing.from_channel inchan] returns a lexer buffer which reads
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from the input channel [inchan], at the current reading position. *)
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val from_string : string -> lexbuf
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(* Create a lexer buffer which reads from
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the given string. Reading starts from the first character in
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the string. An end-of-input condition is generated when the
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end of the string is reached. *)
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val from_function : (string -> int -> int) -> lexbuf
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(* Create a lexer buffer with the given function as its reading method.
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When the scanner needs more characters, it will call the given
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function, giving it a character string [s] and a character
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count [n]. The function should put [n] characters or less in [s],
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starting at character number 0, and return the number of characters
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provided. A return value of 0 means end of input. *)
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(*** Functions for lexer semantic actions *)
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(* The following functions can be called from the semantic actions
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of lexer definitions (the ML code enclosed in braces that
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computes the value returned by lexing functions). They give
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access to the character string matched by the regular expression
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associated with the semantic action. These functions must be
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applied to the argument [lexbuf], which, in the code generated by
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[camllex], is bound to the lexer buffer passed to the parsing
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function. *)
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val lexeme : lexbuf -> string
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(* [Lexing.lexeme lexbuf] returns the string matched by
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the regular expression. *)
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val lexeme_char : lexbuf -> int -> char
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(* [Lexing.lexeme_char lexbuf i] returns character number [i] in
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the matched string. *)
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val lexeme_start : lexbuf -> int
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(* [Lexing.lexeme_start lexbuf] returns the position in the
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input stream of the first character of the matched string.
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The first character of the stream has position 0. *)
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val lexeme_end : lexbuf -> int
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(* [Lexing.lexeme_end lexbuf] returns the position in the input stream
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of the character following the last character of the matched
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string. The first character of the stream has position 0. *)
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(*--*)
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(* The following definitions are used by the generated scanners only.
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They are not intended to be used by user programs. *)
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type lex_tables =
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{ lex_base: string;
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lex_backtrk: string;
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lex_default: string;
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lex_trans: string;
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lex_check: string }
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external engine: lex_tables -> int -> lexbuf -> int = "lex_engine"
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