# [scn_abs.h] Abstract Scanner Interface

## contents

#include "symbols.h"

This module [scn_abs] provides an abstract scanner interface for the term generation module [ptm_gen].

It can be used to integrate an externally defined scanner with the STYX term generation facility.

## The Types

AbsScn_T | Abstract scanner interface type

      Types of the scanner (interface) functions

    typedef void     (*SF_scan      )(Abs_T scanner);
    typedef short    (*SF_tok       )(Abs_T scanner);
    typedef symbol   (*SF_symbol    )(Abs_T scanner);
    typedef long     (*SF_pos       )(Abs_T scanner);
    typedef c_bool   (*SF_flag      )(Abs_T scanner);
    typedef void     (*SF_defID     )(Abs_T scanner, short id);
    typedef c_bool   (*SF_defDynID  )(Abs_T scanner, symbol sym, short id);
    typedef void     (*SF_defTxtID  )(Abs_T scanner, c_string text, short id);
    typedef void     (*SF_defWCTxtID)(Abs_T scanner, wc_string text, short id);
    typedef Any_T    (*SIF_eTerm    )
                     (
                       Abs_T CurPTCfg, c_string language, c_string StartSymbol
                     );
    typedef c_bool   (*SIF_eAccept  )(Abs_T CurPTCfg);

## Init & Quit

    AbsScn_T AS_init(void)

creates an abstract scanner interface

    void AS_quit(AbsScn_T sconfig)

removes abstract scanner interface 'sconfig'

## Specification of the external scanner interface

    void AS_setScanner(AbsScn_T sconfig, Abs_T scanner)

specifies the external 'scanner' of the abstract interface 'sconfig'
( see Scn_Stream )

An external defined scanner must provide the following interface functions. They have to be assigned to the abstract scanner interface before initializing the term generation. That module calls them during the construction of the derivation tree.

    void AS_setFunNextTok(AbsScn_T sconfig, SF_scan nextTok)

specifies 'nextTok' as corresponding function for Stream_next
in the abstract interface 'sconfig'

    void AS_setFunTokID(AbsScn_T sconfig, SF_tok tokID)

specifies 'tokID' as corresponding function for Stream_ctid
in the abstract interface 'sconfig'

    void AS_setFunTokSym(AbsScn_T sconfig, SF_symbol tokSym)

specifies 'tokSym' as corresponding function for Stream_csym
in the abstract interface 'sconfig'

    void AS_setFunStreamSym(AbsScn_T sconfig, SF_symbol streamSym)

specifies 'streamSym' as corresponding function for Stream_cfil
in the abstract interface 'sconfig'

    void AS_setFunTokRow(AbsScn_T sconfig, SF_pos tokRow)

specifies 'tokRow' as corresponding function for Stream_clin
in the abstract interface 'sconfig'

    void AS_setFunTokCol(AbsScn_T sconfig, SF_pos tokCol)

specifies 'tokCol' as corresponding function for Stream_ccol
in the abstract interface 'sconfig'

    void AS_setFunUnicode(AbsScn_T sconfig, SF_flag unicode)

specifies 'tokCol' as corresponding function for Stream_ccol
in the abstract interface 'sconfig'

    void AS_setFunDefEofID(AbsScn_T sconfig, SF_defID defEofID)

specifies 'defEofID' as corresponding function for Stream_defEofId
in the abstract interface 'sconfig'

    void AS_setFunDefErrID(AbsScn_T sconfig, SF_defID defErrID)

specifies 'defErrID' as corresponding function for Stream_defErrId
in the abstract interface 'sconfig'

    void AS_setFunDefTokID(AbsScn_T sconfig, SF_defTxtID defTokID)

specifies 'defTokID' as corresponding function for Stream_defTokId
in the abstract interface 'sconfig'

    void AS_setFunDefDynKeyID(AbsScn_T sconfig, SF_defDynID defDynKeyID)

specifies 'defDynKeyID' as corresponding function for Stream_defDynKeyId
in the abstract interface 'sconfig'

    void AS_setFunDefKeyID(AbsScn_T sconfig, SF_defTxtID defKeyID)

specifies 'defKeyID' as corresponding function for Stream_defKeyId
in the abstract interface 'sconfig'

    void AS_setFunDefWCKeyID(AbsScn_T sconfig, SF_defWCTxtID defWCKeyID)

specifies 'defWCKeyID' as corresponding function for Stream_defWCKeyId
in the abstract interface 'sconfig'

An external defined scanner must call the following handler to construct an embedded language token. This handler will be set by the term construction module.

    void AS_setETermInfo
         (
           AbsScn_T sconfig, Abs_T CurPTCfg, SIF_eTerm eTerm, SIF_eAccept eAccept
         )

specifies 'eTerm' as embedded language token constructor and
'eAccept' as embedded language accept token recognizer
in the abstract interface 'sconfig'

## Accessing the external scanner interface

    Abs_T AS_getScanner(AbsScn_T sconfig)

get the external scanner of the abstract interface 'sconfig'

    SF_scan AS_getFunNextTok(AbsScn_T sconfig)

get the corresponding function for Stream_next
in the abstract interface 'sconfig'

    SF_tok AS_getFunTokID(AbsScn_T sconfig)

get the corresponding function for Stream_ctid
in the abstract interface 'sconfig'

    SF_symbol AS_getFunTokSym(AbsScn_T sconfig)

get the corresponding function for Stream_csym
in the abstract interface 'sconfig'

    SF_symbol AS_getFunStreamSym(AbsScn_T sconfig)

get the corresponding function for Stream_cfil
in the abstract interface 'sconfig'

    SF_pos AS_getFunTokRow(AbsScn_T sconfig)

get the corresponding function for Stream_clin
in the abstract interface 'sconfig'

    SF_pos AS_getFunTokCol(AbsScn_T sconfig)

get the corresponding function for Stream_ccol
in the abstract interface 'sconfig'

    SF_flag AS_getFunUnicode(AbsScn_T sconfig)

get the corresponding function for Stream_ccol
in the abstract interface 'sconfig'

    SF_defID AS_getFunDefEofID(AbsScn_T sconfig)

get the corresponding function for Stream_defEofId
in the abstract interface 'sconfig'

    SF_defID AS_getFunDefErrID(AbsScn_T sconfig)

get the corresponding function for Stream_defErrId
in the abstract interface 'sconfig'

    SF_defTxtID AS_getFunDefTokID(AbsScn_T sconfig)

get the corresponding function for Stream_defTokId
in the abstract interface 'sconfig'

    SF_defDynID AS_getFunDefDynKeyID(AbsScn_T sconfig)

get the corresponding function for Stream_defDynKeyId
in the abstract interface 'sconfig'

    SF_defTxtID AS_getFunDefKeyID(AbsScn_T sconfig)

get the corresponding function for Stream_defKeyId
in the abstract interface 'sconfig'

    SF_defWCTxtID AS_getFunDefWCKeyID(AbsScn_T sconfig)

get the corresponding function for Stream_defWCKeyId
in the abstract interface 'sconfig'

    SIF_eTerm AS_getFunETerm(AbsScn_T sconfig)

get the embedded language token constructor
from the abstract interface 'sconfig'

    SIF_eAccept AS_getEofETerm(AbsScn_T sconfig)

get the embedded language accept token recognizer
from the abstract interface 'sconfig'

    Abs_T AS_getCurPTCfg(AbsScn_T sconfig)

get the current parse term configuration
from the abstract interface 'sconfig'