package hash;

import basic;

public class Hash extends basic.Object {
       /*
        * Hash table implementation
        *
        * There is a list of buckets. Every bucket has a list of
        * pairs (key, value) with the same hash value.
        */
       local bucket;
       static nbuckets = 1039;

       method init( ) {
              bucket = basic.array( nbuckets );
       }

       method _getitem( key ) {
              local hv;
              local pair;

              hv = basic.hash( key ) % nbuckets;
              if (hv = basic.length( bucket )) ||
                      (basic.typeof( bucket[hv] ) != #array))
              {
                      bucket[hv] = #[ #[ key, val ] ];
                      return self;
              }

              for (pair in bucket[hv])
              {
                      for (pair in bucket[hv])
                             if (pair[0] == key) {
                                     pair[1] = val;
                                     return self;
                             }

                      local l = basic.length( bucket[hv] );
                      bucket[hv][l] = #[ key, val ];
                      return self;
              }
       }

       method _keys( ) {
              local keys = #[ ];

              local b, pair;
              for (b in bucket)
              {
                      for (pair in b) keys[basic.length(keys)] = pair[0];
              }

              return keys;
       }

       method _values( ) {
              local values = #[ ];

              local b, pair;
              for (b in bucket)
              {
                      for (pair in b) values[basic.length(values)] = pair[1];
              }

              return values;
       }
}

private ht = [Hash new];

ht["Hello"]  = "World";
ht["Larry"]  = "Wall";
ht[12.6]     = #[ 8, "Goofy", 4.4 ];
ht[16]       = 'o';
ht["Dennis"] = "Ritchie";

basic.print( ht["Larry"], '\n' );
try {
       basic.print( ht["Dennis"], '\n' );
       basic.print( ht["Lorry"], '\n' );
} catch (basic.IndexError e) {
       basic.print( "Exception: ", [e getFullMessage], '\n' );
       basic.print( "    index: ", [e getIndex], '\n' );
}
basic.print( ht["Hello"], '\n' );

private k;
for (k in [ht _keys]) {
       basic.print( k, " -> ", ht[k], '\n' );
}