// [muster_file.cpp] pattern: parsing from a file

/*
   This is only a pattern how to parse from a file. 
   For a concrete example you have to substitute the text within <>.
*/

// necessary includes

#include "stdosx.h"    // base header STYX library
#include "scn_base.h"  // scanner
#include "ptm_gen.h"   // parse & term construction
#include "symbols.h"   // symbol table
#include "hmap.h"      // hash maps

#include "<language>_lim.h"  // <language> scanner table
#include "<language>_pim.h"  // <language> parser table
#include "<language>_int.h"  // <language> language interface


static void parse_and_eval(c_string szPath)
// parse & eval file 
{ Scn_T      pScn;               // scan table
  Scn_Stream pCstream;           // scan stream
  PLR_Tab    pPlr;               // parse table
  PT_Cfg     pPCfg;              // parse configuration
  PT_Term    pTree;              // parse result: derivation tree or NULL
  Scn_get_<language>(&pScn);                 // create scan table
  pPlr = PLR_get_<language>();               // create parse table
  pCstream = Stream_file(pScn,"",szPath,""); // create scanner from 'szPath'
  /* you can split the path into the following components
    pCstream = Stream_file(pScn,<EnvVar>,<BaseName>,<Suffix>); 
  */
  pPCfg = PT_init(pPlr,pCstream); // create parse configuration
  pTree = PT_PARSE(pPCfg,"");     // parse from first start nonterminal
  // initializes error count with syntax error count
  PT_setErrorCnt(PT_synErrorCnt(pPCfg));
  // no errors --> eval derivation tree
  if( PT_errorCnt() == 0 ) 
  { <language><start nonterminal>   pStart;  // start nonterminal tree node
    <language><child nonterminal 1> pChild1; // first child node
    // ...
    <language><child nonterminal N> pChildN; // last child node
    // extract start nonterminal tree node
    assert0( <language>_Start_<start nonterminal>(pTree,&pStart), "");
    // end command --> stop process
    if( <language><start nonterminal>_<production>
        (pStart,&pChild1, ..., &pChildN) ) 
    {
      // further evaluation ...
    }
  }
  if( pTree != NULL ) PT_delT(pTree); // release derivation tree
  PT_quit(pPCfg);                     // release parse configuration
  Stream_close(pCstream);             // close scan stream
  Stream_free(pCstream);              // release scan stream
  Scn_free(pScn);                     // release scan table
  PLR_delTab(pPlr);                   // release parse table
}


int main(int argc, char* argv[])
{ 
  // modul initialisation for hash maps and symbols
  MAP_init();
  initSymbols();
  // init language symbols
  <language>_initSymbols();
  // parse and evaluate file
  parse_and_eval(argv[0]);
  // release language symbols
  <language>_quitSymbols();
  // modul termination for hash maps and symbols
  freeSymbols();
  MAP_quit();
  BUG_CORE;
  return 0;
}