term_size/2

Documentation
- Reference manual
  - The SWI-Prolog library
    - library(terms): Term manipulation
- Packages

Availability::- use_module(library(terms)).(can be autoloaded)

[det]term_size(@Term, -Size)

True if Size is the size in cells occupied by Term on the global (term) stack. A cell is 4 bytes on 32-bit machines and 8 bytes on 64-bit machines. The calculation does take sharing into account. For example:

?- A = a(1,2,3), term_size(A,S).
S = 4.
?- A = a(1,2,3), term_size(a(A,A),S).
S = 7.
?- term_size(a(a(1,2,3), a(1,2,3)), S).
S = 11.

Note that small objects such as atoms and small integers have a size 0. Space is allocated for floats, large integers, strings and compound terms.