46 lines
1.6 KiB
OCaml
46 lines
1.6 KiB
OCaml
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(* Simple lexer for the Mini-ML language *)
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(* Error reporting *)
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type message = string
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exception Error of message Region.reg
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(* Tokeniser *)
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(* The call [get_token ~log] evaluates in a lexer (a.k.a
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tokeniser or scanner) whose type is [Lexing.lexbuf -> Token.t].
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The argument [log] is a logger. As its type shows and suggests,
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it is a pair made of an output channel and a printer for
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tokens. The lexer would use any logger to print the recognised
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tokens to the given channel. If no logger is given to [get_token],
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no printing takes place while the lexer runs.
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The call [reset ~file ~line buffer] modifies in-place the lexing
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buffer [buffer] so the lexing engine records that the file
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associated with [buffer] is named [file], and the current line is
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[line]. This function is useful when lexing a file that has been
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previously preprocessed by the C preprocessor, in which case the
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argument [file] is the name of the file that was preprocessed,
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_not_ the preprocessed file (of which the user is not normally
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aware). By default, the [line] argument is [1].
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*)
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type logger = out_channel * (out_channel -> Token.t -> unit)
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val get_token : ?log:logger -> Lexing.lexbuf -> Token.t
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val reset : file:string -> ?line:int -> Lexing.lexbuf -> unit
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(* Debugging *)
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type file_path = string
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val iter :
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(Lexing.lexbuf -> out_channel -> Token.t -> unit) -> file_path option -> unit
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val trace : file_path option -> unit
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val prerr : kind:string -> message Region.reg -> unit
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val format_error : kind:string -> message Region.reg -> string
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val output_token : Lexing.lexbuf -> out_channel -> Token.t -> unit
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