hashed

Hash a variable's contents.

Syntax

status = hashed ( variable ) ;

Arguments

list variable

• A list variable.

Return Value

str status

• $ACKNOWLEDGE

  The variable's contents have been hashed for faster lookup.

  The STATUS variable is set to $ACKNOWLEDGE

Exceptions

%ARGUMENT : Invalid arguments. Usage: status = hashed ( variable ) ;

%IDENTIFIER : 'variable' argument is not a valid identifier, literal, or reference

Description

A hash table is a mapping between the elements of a list and their values. With a hash table, an efficient lookup mechanism is employed to retrieve the data elements. Hashing is most useful for list variables with many unique elements; it can result in better performance when accessing the variables' elements. The unlashed method is used to un-hash the variable.

Examples

To execute the example below, press or modify the example to try different variations. wordCount = {} ; hashed wordCount ; h = fopen ( book.dat , r ) ; while ( 1 ) { line = fget ( h ) ; if (STATUS == %EOF ) break ; words = strtok line ; n = count words ; for (i=0;i<n;i++) { word = words[i] ; /* Hashed wordCount makes this * next part fast. */ if ( exists(wordCount.*word) ) wordCount.*word++ ; else int wordCount.*word=0; } } fclose(h); n = count wordCount ; for (I=0;I<n;I++) puts { Count of ,wordCount[I], = ,*wordCount[I] } ; wordCount = {} ; hashed wordCount ; h = fopen ( book.dat , r ) ; while ( 1 ) { line = fget ( h ) ; if (STATUS == %EOF ) break ; words = strtok line ; n = count words ; for (i=0;i<n;i++) { word = words[i] ; /* Hashed wordCount makes this * next part fast. */ if ( exists(wordCount.*word) ) wordCount.*word++ ; else int wordCount.*word=0; } } fclose(h); n = count wordCount ; for (I=0;I<n;I++) puts { Count of ,wordCount[I], = ,*wordCount[I] } ;

Related Links

unhashed