Deepcopy: Difference between revisions

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=={{header|Phix}}==
=={{header|Phix}}==
{{libheader|Phix/basics}}
Handled natively. Phix uses reference counting with copy-on-write semantics; the initial copy is fast even for huge complex and deeply nested structures (copying a single machine-word-sized reference and incrementing a single machine-word-sized reference count), and when a shared object (anything with a refcount>1) is modified, an internal clone of the minimum necessary levels occurs, with all the rest of the structure remaining shared (but obviously still properly protected in the same way).
Handled natively. Phix uses reference counting with copy-on-write semantics; the initial copy is fast even for huge complex and deeply nested structures (copying a single machine-word-sized reference and incrementing a single machine-word-sized reference count), and when a shared object (anything with a refcount>1) is modified, an internal clone of the minimum necessary levels occurs, with all the rest of the structure remaining shared (but obviously still properly protected in the same way).
<lang Phix>object a, b
<!--<lang Phix>-->
<span style="color: #004080;">object</span> <span style="color: #000000;">a<span style="color: #0000FF;">,</span> <span style="color: #000000;">b</span>
a = {1,{2,3},"four",{5.6,7,{8.9}}}
<span style="color: #000000;">a</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{<span style="color: #000000;">1<span style="color: #0000FF;">,<span style="color: #0000FF;">{<span style="color: #000000;">2<span style="color: #0000FF;">,<span style="color: #000000;">3<span style="color: #0000FF;">}<span style="color: #0000FF;">,<span style="color: #008000;">"four"<span style="color: #0000FF;">,<span style="color: #0000FF;">{<span style="color: #000000;">5.6<span style="color: #0000FF;">,<span style="color: #000000;">7<span style="color: #0000FF;">,<span style="color: #0000FF;">{<span style="color: #000000;">8.9<span style="color: #0000FF;">}<span style="color: #0000FF;">}<span style="color: #0000FF;">}</span>
b = a
<span style="color: #000000;">b</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">a</span>
b[3] = 4
<span style="color: #000000;">b<span style="color: #0000FF;">[<span style="color: #000000;">3<span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">4</span>
?a
<span style="color: #0000FF;">?<span style="color: #000000;">a</span>
⚫
?b</lang>
<span style="color: #0000FF;">?<span style="color: #000000;">b
⚫
<!--</lang>-->
{{out}}
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Should you for some (probably misguided) reason really want it, a recursive clone function might look like this:
Should you for some (probably misguided) reason really want it, a recursive clone function might look like this:
<lang Phix>function deep_copy(object o)
<!--<lang Phix>-->
<span style="color: #008080;">function</span> <span style="color: #000000;">deep_copy<span style="color: #0000FF;">(<span style="color: #004080;">object</span> <span style="color: #000000;">o<span style="color: #0000FF;">)</span>
object res
<span style="color: #004080;">object</span> <span style="color: #000000;">res</span>
if atom(o) then
<span style="color: #008080;">if</span> <span style="color: #004080;">atom<span style="color: #0000FF;">(<span style="color: #000000;">o<span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
res = o
<span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">o</span>
else
<span style="color: #008080;">else</span>
res = repeat(' ',length(o))
<span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat<span style="color: #0000FF;">(<span style="color: #008000;">' '<span style="color: #0000FF;">,<span style="color: #7060A8;">length<span style="color: #0000FF;">(<span style="color: #000000;">o<span style="color: #0000FF;">)<span style="color: #0000FF;">)</span>
for i=1 to length(o) do
<span style="color: #008080;">for</span> <span style="color: #000000;">i<span style="color: #0000FF;">=<span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length<span style="color: #0000FF;">(<span style="color: #000000;">o<span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
res[i] = deep_copy(o[i])
<span style="color: #000000;">res<span style="color: #0000FF;">[<span style="color: #000000;">i<span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">deep_copy<span style="color: #0000FF;">(<span style="color: #000000;">o<span style="color: #0000FF;">[<span style="color: #000000;">i<span style="color: #0000FF;">]<span style="color: #0000FF;">)</span>
end for
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
end if
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
return res
<span style="color: #008080;">return</span> <span style="color: #000000;">res</span>
end function
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>

object c = deep_copy(b)
<span style="color: #004080;">object</span> <span style="color: #000000;">c</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">deep_copy<span style="color: #0000FF;">(<span style="color: #000000;">b<span style="color: #0000FF;">)</span>
⚫
?c</lang>
<span style="color: #0000FF;">?<span style="color: #000000;">c
⚫
<!--</lang>-->
Or you could just serialize and deserialize:
Or you could just serialize and deserialize:
<lang Phix>include builtins\serialize.e
<!--<lang Phix>-->
<span style="color: #008080;">include</span> <span style="color: #000000;">builtins<span style="color: #0000FF;">\<span style="color: #000000;">serialize<span style="color: #0000FF;">.<span style="color: #000000;">e</span>
object d = deserialize(serialize(a))
<span style="color: #004080;">object</span> <span style="color: #000000;">d</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">deserialize<span style="color: #0000FF;">(<span style="color: #000000;">serialize<span style="color: #0000FF;">(<span style="color: #000000;">a<span style="color: #0000FF;">)<span style="color: #0000FF;">)</span>
⚫
?d</lang>
<span style="color: #0000FF;">?<span style="color: #000000;">d
⚫
<!--</lang>-->
{{out}}
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