hashtable-size - get the number of associations in a hashtable

LIBRARY

(import (rnrs))                     ;R6RS
(import (rnrs hashtables))          ;R6RS

SYNOPSIS

(hashtable-size hashtable)

DESCRIPTION

Returns the number of keys contained in hashtable.

RETURN VALUES

Returns a single value; an exact non-negative integer object.

EXAMPLES

(map (lambda (n)
       (do ((ht (make-eqv-hashtable))
            (i 0 (+ i 1)))
           ((> i n)
            (hashtable-size ht))
         (do ((j 0 (+ j 1)))
             ((> j n))
           (hashtable-set! ht (* i j) #t))))
     '(0 1 2 3 4 5 6 7 8 9 10 11 12 13))
    => (1 2 4 7 10 15 19 26 31 37 43 54 60 73)

COMPATIBILITY

This procedure is unique to R6RS. Similar procedures exist in SRFI-69 and SRFI-125.

ERRORS

This procedure can raise exceptions with the following condition types:
&assertion (R6RS)
The wrong number of arguments was passed or an argument was outside its domain. In particular, hashtable should be a hashtable.

SEE ALSO

make-hashtable(3scm), hashtable-keys(3scm), hashtable-entries(3scm)

STANDARDS

R6RS

HISTORY

This procedure first appeared in R6RS. An equivalent procedure already existed in SRFI-69 under the name hash-table-size.

AUTHORS

This page is part of the scheme-manpages project. It includes materials from the RnRS documents. More information can be found at https://github.com/schemedoc/manpages/.

Markup created by unroff 1.0sc,    March 04, 2023.