Christian Wirth wrote: > I'm trying to copy a nested term structure (a list and a tree). Use one of the following, they all preserve variable sharing: writeq/2 and read/2: Use writeq to write the term to any I/O stream (file/pipe/socket/queue etc), and use read/2 to read it back. term_string/2 for term to string and string to term. Does basically the same thing as the writeq/read pair, except it makes an explicit string. term_to_bytes/2 and bytes_to_term/2 also convert arbitrary terms to strings and back, but the format is not human readable. Examples: ?- Old = foo(X, [3, X, Y]), open(queue(""), update, Q), writeq(Q, Old), read(Q, New). Old = foo(_83, [3, _83, _96]) X = _83 Y = _96 Q = 27 New = foo(_550, [3, _550, _559]) Yes (0.00s cpu) ?- Old = foo(X, [3, X, Y]), term_string(Old, String), term_string(New, String). Old = foo(_82, [3, _82, _95]) X = _82 Y = _95 String = "foo(_82, [3, _82, _95])" New = foo(_466, [3, _466, _475]) Yes (0.00s cpu) ?- Old=foo(X,[3,X,Y]), term_to_bytes(Old,String), bytes_to_term(String,New). Old = foo(_82, [3, _82, _95]) X = _82 Y = _95 String = "\000\000\000\030\001\002\v\002\003foo\377\b\000\n\376\b\001X\n\003\000\016\377\b\000\022\377\026\t\376\026\001Y" New = foo(_460, [3, _460, _467]) Yes (0.00s cpu) -- JoachimReceived on Fri Jun 25 2010 - 01:28:13 CEST
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