package nl.bluering;

/**
* a Syntel is a SYNTax ELement. These objects define the shorthand notations
* a parser or writer can recognize or use, like brackets, quotes and operators.
*/

public class Syntel
{
 int precount;//0 or 1
 String instring;//the first string, the one it is recognized by.
 String repeat;//the , in { , , }. can be empty, or null
 String end;//the last string, the closing bracket; can be empty
 int minpost;//minimal number of elements after the instring
 int maxpost;//maximal number of elements after the instring
 String fname;//the name the object gets. can be null if just one object inside
 int level;//the level of this object
 int leftlevel;//the maximal allowed level of objects left from instring
 int rightlevel;//the maximal allowed level of objects right from instring
 boolean isquote;//if this is a quote, the enclosed characters are not parsed
 Expression endexp=null;//only for quotes: quote(end)
 Expression notendexp=null;//only for quotes: allout(end[0])
 Expression repeatexp=null;
 
 static int MAXLEVEL=1200;//the maximal level. minlevel is 0.
 static int MAXREP=100;//parser maximum, to avoid crashing parser
 
 private Syntel(int a,String i,String r, String e, int min,int max,
 								String fn,int l,int ll,int rl,boolean b)
 {precount=a;
  instring=i;
  repeat=r;
  end=e;
  minpost=min;
  maxpost=max;
  fname=fn;
  level=l;
  leftlevel=ll;
  rightlevel=rl;
  isquote=b;  
 }
 
 
 
 public static boolean aunderb(Syntel a,Syntel b){
  return a.fitsunder(b.leftlevel);
 }
 public static boolean aoverb(Syntel a,Syntel b){
  return b.fitsunder(a.rightlevel);
 }
/**
* returns whether this Syntel can be fitted under
* the given level.
*/	
 public boolean fitsunder(int l) {return (level<=l);}
 public boolean isprefix() {return precount==0;}
 public int minarg() {return precount+minpost;}
 public int maxarg() {return precount+maxpost;}
 
 public static Syntel newsyntel(int a,String i,String rep, String e, int min,int max,
 								String fn,int l,int ll,int rl,boolean b)
 {Syntel r=new Syntel(a,i,rep,e,min,max,fn,l,ll,rl,b);
  if(!b&&(r.minarg()<1||r.minarg()>r.maxarg()||l<0||rl<0||rl<0))
   return null;
  if(l>MAXLEVEL||rl>MAXLEVEL||ll>MAXLEVEL||i==null||i.length()==0)
   return null;
  if((max>1&&r==null)||a<0||a>1||min<0)
   return null;
  if (r.end!=null)
   r.endexp=ExpParser.addws(new Expression("quote",1).add(r.end));
  if(r.end!=null&&r.isquote)
  {r.notendexp=new Expression("allout",1).add(r.end.substring(0,1));
  }
  if(r.repeat!=null)
   r.repeatexp=ExpParser.addws(new Expression("quote",1).add(r.repeat)); 
  return r;    
 }
 
 public static Syntel newbracket(String pre,String post,String repeat,String fname)
 {
  Syntel r=newsyntel(0,pre,repeat,post,1,1,fname,0,0,MAXLEVEL,false);
  if(repeat!=null)
  	r.maxpost=MAXREP;
  return r;
 }
 public static Syntel newquote(String pre,String post,String fname)
 {
  Syntel r=newsyntel(0,pre,null,post,0,0,fname,0,0,0,true);
  return r;
 }
 /**
 * the asociation modes: left a+b+c = (a+b)+c
 * not: a+b+c not allowed
 * right: a+b+c is a+(b+c)
 * if repeat is enabled, it is only used for different operators with the same level.
 */
 public final static int LEFT=-1,NOT=0,RIGHT=1;
 public static Syntel newinop(String name,String fname,int level, int asocmode,boolean repeat)
 {
  Syntel r=newsyntel(1,name,name,null,1,repeat?MAXREP:1,fname,level,level-1,level-1,false);
  if(asocmode==LEFT) r.leftlevel=level;
  if(asocmode==RIGHT) r.rightlevel=level;
  r.isquote=false;	
  return r;
 }
 public static Syntel newrepeatinop(String name,String fname,int level)
 {return newinop(name,fname,level,NOT,true);
 }
 
 public static Syntel newpreop(String name,String fname,int level, int asocmode)
 {
  Syntel r=newsyntel(0,name,null,"",1,1,fname,level,
    (asocmode==RIGHT)?level:level-1,0,false);
  return r;
 }
 
 public static Syntel newpostop(String name,String fname,int level, int asocmode)
 {
  Syntel r=newsyntel(1,name,null,"",0,0,fname,level,0,
    (asocmode==LEFT)?level:level-1,false);
  return r;
 }
}