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<pre id='vimCodeElement'>
<span class="Comment">// To recursively copy containers and any addresses they contain, use</span>
<span class="Comment">// 'deep-copy'.</span>
<span class="Comment">//</span>
<span class="Comment">// Invariant: After a deep-copy its ingredient and result will point to no</span>
<span class="Comment">// common addresses.</span>
<span class="Comment">// Implications: Refcounts of all data pointed to by the original ingredient</span>
<span class="Comment">// will remain unchanged. Refcounts of all data pointed to by the (newly</span>
<span class="Comment">// created) result will be 1, in the absence of cycles.</span>
<span class="Comment">//</span>
<span class="Comment">// We do handle cycles in the ingredient, however. All cycles are translated</span>
<span class="Comment">// to new cycles in the product.</span>

<span class="Delimiter">:(scenario deep_copy_number)</span>
def main [
  local-scope
  <span class="Normal">x</span>:num<span class="Special"> &lt;- </span>copy <span class="Constant">34</span>
  <span class="Normal">y</span>:num<span class="Special"> &lt;- </span>deep-copy x
  <span class="Constant">10</span>:<span class="Normal">bool</span>/<span class="Special">raw &lt;- </span>equal x<span class="Delimiter">,</span> y
]
<span class="Comment"># non-address primitives are identical</span>
<span class="traceContains">+mem: storing 1 in location 10</span>

<span class="Delimiter">:(scenario deep_copy_container_without_address)</span>
container foo [
  <span class="Normal">x</span>:num
  <span class="Normal">y</span>:num
]
def main [
  local-scope
  <span class="Normal">a</span>:foo<span class="Special"> &lt;- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">35</span>
  <span class="Normal">b</span>:foo<span class="Special"> &lt;- </span>deep-copy a
  <span class="Constant">10</span>:<span class="Normal">bool</span>/<span class="Special">raw &lt;- </span>equal a<span class="Delimiter">,</span> b
]
<span class="Comment"># containers are identical as long as they don't contain addresses</span>
<span class="traceContains">+mem: storing 1 in location 10</span>

<span class="Delimiter">:(scenario deep_copy_address)</span>
<span class="Special">% Memory_allocated_until = 200;</span>
def main [
  <span class="Comment"># avoid all memory allocations except the implicit ones inside deep-copy, so</span>
  <span class="Comment"># that the result is deterministic</span>
  <span class="Constant">1</span>:&amp;:num<span class="Special"> &lt;- </span>copy <span class="Constant">100</span>/unsafe  <span class="Comment"># pretend allocation</span>
  *<span class="Constant">1</span>:&amp;:num<span class="Special"> &lt;- </span>copy <span class="Constant">34</span>
  <span class="Constant">2</span>:&amp;:num<span class="Special"> &lt;- </span>deep-copy <span class="Constant">1</span>:&amp;:num
  <span class="Constant">10</span>:<span class="Normal">bool</span><span class="Special"> &lt;- </span>equal <span class="Constant">1</span>:&amp;:num<span class="Delimiter">,</span> <span class="Constant">2</span>:&amp;:num
  <span class="Constant">11</span>:<span class="Normal">bool</span><span class="Special"> &lt;- </span>equal *<span class="Constant">1</span>:&amp;:num<span class="Delimiter">,</span> *<span class="Constant">2</span>:&amp;:num
  <span class="Constant">2</span>:&amp;:num<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
]
<span class="Comment"># the result of deep-copy is a new address</span>
<span class="traceContains">+mem: storing 0 in location 10</span>
<span class="Comment"># however, the contents are identical</span>
<span class="traceContains">+mem: storing 1 in location 11</span>
<span class="Comment"># the result of deep-copy gets a refcount of 1</span>
<span class="Comment"># (its address 202 = 200 base + 2 for temporary space inside deep-copy)</span>
<span class="traceContains">+run: {2: (&quot;address&quot; &quot;number&quot;)} &lt;- copy {0: &quot;literal&quot;}</span>
<span class="traceContains">+mem: decrementing refcount of 202: 1 -&gt; 0</span>
<span class="traceContains">+abandon: saving 202 in free-list of size 2</span>

<span class="Delimiter">:(scenario deep_copy_address_to_container)</span>
<span class="Special">% Memory_allocated_until = 200;</span>
def main [
  <span class="Comment"># avoid all memory allocations except the implicit ones inside deep-copy, so</span>
  <span class="Comment"># that the result is deterministic</span>
  <span class="Constant">1</span>:&amp;:point<span class="Special"> &lt;- </span>copy <span class="Constant">100</span>/unsafe  <span class="Comment"># pretend allocation</span>
  *<span class="Constant">1</span>:&amp;:point<span class="Special"> &lt;- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">35</span>
  <span class="Constant">2</span>:&amp;:point<span class="Special"> &lt;- </span>deep-copy <span class="Constant">1</span>:&amp;:point
  <span class="Constant">10</span>:<span class="Normal">bool</span><span class="Special"> &lt;- </span>equal <span class="Constant">1</span>:&amp;:point<span class="Delimiter">,</span> <span class="Constant">2</span>:&amp;:point
  <span class="Constant">11</span>:<span class="Normal">bool</span><span class="Special"> &lt;- </span>equal *<span class="Constant">1</span>:&amp;:point<span class="Delimiter">,</span> *<span class="Constant">2</span>:&amp;:point
]
<span class="Comment"># the result of deep-copy is a new address</span>
<span class="traceContains">+mem: storing 0 in location 10</span>
<span class="Comment"># however, the contents are identical</span>
<span class="traceContains">+mem: storing 1 in location 11</span>

<span class="Delimiter">:(scenario deep_copy_address_to_address)</span>
<span class="Special">% Memory_allocated_until = 200;</span>
def main [
  <span class="Comment"># avoid all memory allocations except the implicit ones inside deep-copy, so</span>
  <span class="Comment"># that the result is deterministic</span>
  <span class="Constant">1</span>:&amp;:&amp;:num<span class="Special"> &lt;- </span>copy <span class="Constant">100</span>/unsafe  <span class="Comment"># pretend allocation</span>
  *<span class="Constant">1</span>:&amp;:&amp;:num<span class="Special"> &lt;- </span>copy <span class="Constant">150</span>/unsafe
  **<span class="Constant">1</span>:&amp;:&amp;:num<span class="Special"> &lt;- </span>copy <span class="Constant">34</span>
  <span class="Constant">2</span>:&amp;:&amp;:num<span class="Special"> &lt;- </span>deep-copy <span class="Constant">1</span>:&amp;:&amp;:num
  <span class="Constant">10</span>:<span class="Normal">bool</span><span class="Special"> &lt;- </span>equal <span class="Constant">1</span>:&amp;:&amp;:num<span class="Delimiter">,</span> <span class="Constant">2</span>:&amp;:&amp;:num
  <span class="Constant">11</span>:<span class="Normal">bool</span><span class="Special"> &lt;- </span>equal *<span class="Constant">1</span>:&amp;:&amp;:num<span class="Delimiter">,</span> *<span class="Constant">2</span>:&amp;:&amp;:num
  <span class="Constant">12</span>:<span class="Normal">bool</span><span class="Special"> &lt;- </span>equal **<span class="Constant">1</span>:&amp;:&amp;:num<span class="Delimiter">,</span> **<span class="Constant">2</span>:&amp;:&amp;:num
]
<span class="Comment"># the result of deep-copy is a new address</span>
<span class="traceContains">+mem: storing 0 in location 10</span>
<span class="Comment"># any addresses in it or pointed to it are also new</span>
<span class="traceContains">+mem: storing 0 in location 11</span>
<span class="Comment"># however, the non-address contents are identical</span>
<span class="traceContains">+mem: storing 1 in location 12</span>

<span class="Delimiter">:(scenario deep_copy_array)</span>
<span class="Special">% Memory_allocated_until = 200;</span>
def main [
  <span class="Comment"># avoid all memory allocations except the implicit ones inside deep-copy, so</span>
  <span class="Comment"># that the result is deterministic</span>
  <span class="Constant">100</span>:num<span class="Special"> &lt;- </span>copy <span class="Constant">1</span>  <span class="Comment"># pretend refcount</span>
  <span class="Constant">101</span>:num<span class="Special"> &lt;- </span>copy <span class="Constant">3</span>  <span class="Comment"># pretend array length</span>
  <span class="Constant">1</span>:&amp;:@:num<span class="Special"> &lt;- </span>copy <span class="Constant">100</span>/unsafe  <span class="Comment"># pretend allocation</span>
  put-index *<span class="Constant">1</span>:&amp;:@:num<span class="Delimiter">,</span> <span class="Constant">0</span><span class="Delimiter">,</span> <span class="Constant">34</span>
  put-index *<span class="Constant">1</span>:&amp;:@:num<span class="Delimiter">,</span> <span class="Constant">1</span><span class="Delimiter">,</span> <span class="Constant">35</span>
  put-index *<span class="Constant">1</span>:&amp;:@:num<span class="Delimiter">,</span> <span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">36</span>
  stash [old:]<span class="Delimiter">,</span> *<span class="Constant">1</span>:&amp;:@:num
  <span class="Constant">2</span>:&amp;:@:num<span class="Special"> &lt;- </span>deep-copy <span class="Constant">1</span>:&amp;:@:num
  stash <span class="Constant">2</span>:&amp;:@:num
  stash [<span class="Normal">new</span>:]<span class="Delimiter">,</span> *<span class="Constant">2</span>:&amp;:@:num
  <span class="Constant">10</span>:<span class="Normal">bool</span><span class="Special"> &lt;- </span>equal <span class="Constant">1</span>:&amp;:@:num<span class="Delimiter">,</span> <span class="Constant">2</span>:&amp;:@:num
  <span class="Constant">11</span>:<span class="Normal">bool</span><span class="Special"> &lt;- </span>equal *<span class="Constant">1</span>:&amp;:@:num<span class="Delimiter">,</span> *<span class="Constant">2</span>:&amp;:@:num
]
<span class="traceContains">+app: old: 3 34 35 36</span>
<span class="traceContains">+app: new: 3 34 35 36</span>
<span class="Comment"># the result of deep-copy is a new address</span>
<span class="traceContains">+mem: storing 0 in location 10</span>
<span class="Comment"># however, the contents are identical</span>
<span class="traceContains">+mem: storing 1 in location 11</span>

<span class="Delimiter">:(scenario deep_copy_container_with_address)</span>
container foo [
  <span class="Normal">x</span>:num
  <span class="Normal">y</span>:&amp;:num
]
def main [
  local-scope
  <span class="Normal">y0</span>:&amp;:num<span class="Special"> &lt;- </span><span class="Normal">new</span> number:type
  *y0<span class="Special"> &lt;- </span>copy <span class="Constant">35</span>
  <span class="Normal">a</span>:foo<span class="Special"> &lt;- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> y0
  <span class="Normal">b</span>:foo<span class="Special"> &lt;- </span>deep-copy a
  <span class="Constant">10</span>:<span class="Normal">bool</span>/<span class="Special">raw &lt;- </span>equal a<span class="Delimiter">,</span> b
  <span class="Normal">y1</span>:&amp;:num<span class="Special"> &lt;- </span>get b<span class="Delimiter">,</span> y:offset
  <span class="Constant">11</span>:<span class="Normal">bool</span>/<span class="Special">raw &lt;- </span>equal y0<span class="Delimiter">,</span> y1
  <span class="Constant">12</span>:num/<span class="Special">raw &lt;- </span>copy *y1
]
<span class="Comment"># containers containing addresses are not identical to their deep copies</span>
<span class="traceContains">+mem: storing 0 in location 10</span>
<span class="Comment"># the addresses they contain are not identical either</span>
<span class="traceContains">+mem: storing 0 in location 11</span>
<span class="traceContains">+mem: storing 35 in location 12</span>

<span class="Delimiter">:(scenario deep_copy_exclusive_container_with_address)</span>
exclusive-container foo [
  <span class="Normal">x</span>:num
  <span class="Normal">y</span>:&amp;:num
]
def main [
  local-scope
  <span class="Normal">y0</span>:&amp;:num<span class="Special"> &lt;- </span><span class="Normal">new</span> number:type
  *y0<span class="Special"> &lt;- </span>copy <span class="Constant">34</span>
  <span class="Normal">a</span>:foo<span class="Special"> &lt;- </span>merge <span class="Constant">1</span>/y<span class="Delimiter">,</span> y0
  <span class="Normal">b</span>:foo<span class="Special"> &lt;- </span>deep-copy a
  <span class="Constant">10</span>:<span class="Normal">bool</span>/<span class="Special">raw &lt;- </span>equal a<span class="Delimiter">,</span> b
  <span class="Normal">y1</span>:&amp;:num<span class="Delimiter">,</span> z:<span class="Normal">bool</span><span class="Special"> &lt;- </span>maybe-convert b<span class="Delimiter">,</span> y:variant
  <span class="Constant">11</span>:<span class="Normal">bool</span>/<span class="Special">raw &lt;- </span>equal y0<span class="Delimiter">,</span> y1
  <span class="Constant">12</span>:num/<span class="Special">raw &lt;- </span>copy *y1
]
<span class="Comment"># exclusive containers containing addresses are not identical to their deep copies</span>
<span class="traceContains">+mem: storing 0 in location 10</span>
<span class="Comment"># the addresses they contain are not identical either</span>
<span class="traceContains">+mem: storing 0 in location 11</span>
<span class="traceContains">+mem: storing 34 in location 12</span>

<span class="Delimiter">:(scenario deep_copy_exclusive_container_with_container_with_address)</span>
exclusive-container foo [
  <span class="Normal">x</span>:num
  <span class="Normal">y</span>:bar  <span class="Comment"># inline</span>
]
container bar [
  <span class="Normal">x</span>:&amp;:num
]
def main [
  local-scope
  <span class="Normal">y0</span>:&amp;:num<span class="Special"> &lt;- </span><span class="Normal">new</span> number:type
  *y0<span class="Special"> &lt;- </span>copy <span class="Constant">34</span>
  <span class="Normal">a</span>:bar<span class="Special"> &lt;- </span>merge y0
  <span class="Normal">b</span>:foo<span class="Special"> &lt;- </span>merge <span class="Constant">1</span>/y<span class="Delimiter">,</span> a
  <span class="Normal">c</span>:foo<span class="Special"> &lt;- </span>deep-copy b
  <span class="Constant">10</span>:<span class="Normal">bool</span>/<span class="Special">raw &lt;- </span>equal b<span class="Delimiter">,</span> c
  <span class="Normal">d</span>:bar<span class="Delimiter">,</span> z:<span class="Normal">bool</span><span class="Special"> &lt;- </span>maybe-convert c<span class="Delimiter">,</span> y:variant
  <span class="Normal">y1</span>:&amp;:num<span class="Special"> &lt;- </span>get d<span class="Delimiter">,</span> x:offset
  <span class="Constant">11</span>:<span class="Normal">bool</span>/<span class="Special">raw &lt;- </span>equal y0<span class="Delimiter">,</span> y1
  <span class="Constant">12</span>:num/<span class="Special">raw &lt;- </span>copy *y1
]
<span class="Comment"># exclusive containers containing addresses are not identical to their deep copies</span>
<span class="traceContains">+mem: storing 0 in location 10</span>
<span class="Comment"># sub-containers containing addresses are not identical either</span>
<span class="traceContains">+mem: storing 0 in location 11</span>
<span class="traceContains">+mem: storing 34 in location 12</span>

<span class="Delimiter">:(before &quot;End Primitive Recipe Declarations&quot;)</span>
DEEP_COPY<span class="Delimiter">,</span>
<span class="Delimiter">:(before &quot;End Primitive Recipe Numbers&quot;)</span>
put<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;deep-copy&quot;</span><span class="Delimiter">,</span> DEEP_COPY<span class="Delimiter">);</span>
<span class="Delimiter">:(before &quot;End Primitive Recipe Checks&quot;)</span>
<span class="Normal">case</span> DEEP_COPY: <span class="Delimiter">{</span>
  <span class="Normal">if</span> <span class="Delimiter">(</span>SIZE<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">)</span> != <span class="Constant">1</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
    raise &lt;&lt; maybe<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;'deep-copy' takes exactly one ingredient rather than '&quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>original_string &lt;&lt; <span class="Constant">&quot;'</span><span class="cSpecial">\n</span><span class="Constant">&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
    <span class="Identifier">break</span><span class="Delimiter">;</span>
  <span class="Delimiter">}</span>
  <span class="Normal">if</span> <span class="Delimiter">(</span>SIZE<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>products<span class="Delimiter">)</span> != <span class="Constant">1</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
    raise &lt;&lt; maybe<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;'deep-copy' takes exactly one ingredient rather than '&quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>original_string &lt;&lt; <span class="Constant">&quot;'</span><span class="cSpecial">\n</span><span class="Constant">&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
    <span class="Identifier">break</span><span class="Delimiter">;</span>
  <span class="Delimiter">}</span>
  <span class="Normal">if</span> <span class="Delimiter">(</span>!types_strictly_match<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">),</span> inst<span class="Delimiter">.</span>products<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
    raise &lt;&lt; maybe<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;'deep-copy' requires its ingredient and product to be the same type, but got '&quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>original_string &lt;&lt; <span class="Constant">&quot;'</span><span class="cSpecial">\n</span><span class="Constant">&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
    <span class="Identifier">break</span><span class="Delimiter">;</span>
  <span class="Delimiter">}</span>
  <span class="Identifier">break</span><span class="Delimiter">;</span>
<span class="Delimiter">}</span>
<span class="Delimiter">:(before &quot;End Primitive Recipe Implementations&quot;)</span>
<span class="Normal">case</span> DEEP_COPY: <span class="Delimiter">{</span>
  <span class="Normal">const</span> reagent&amp; input = current_instruction<span class="Delimiter">().</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">);</span>
  <span class="Comment">// allocate a tiny bit of temporary space for deep_copy()</span>
  trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;deep-copy: allocating space for temporary&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
  reagent tmp<span class="Delimiter">(</span><span class="Constant">&quot;tmp:address:number&quot;</span><span class="Delimiter">);</span>
  tmp<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span>allocate<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">));</span>
  products<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>deep_copy<span class="Delimiter">(</span>input<span class="Delimiter">,</span> tmp<span class="Delimiter">));</span>
  <span class="Comment">// reclaim Mu memory allocated for tmp</span>
  trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;deep-copy: reclaiming temporary&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
  abandon<span class="Delimiter">(</span>tmp<span class="Delimiter">.</span>value<span class="Delimiter">,</span> tmp<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">,</span> payload_size<span class="Delimiter">(</span>tmp<span class="Delimiter">));</span>
  <span class="Comment">// reclaim host memory allocated for tmp.type when tmp goes out of scope</span>
  <span class="Identifier">break</span><span class="Delimiter">;</span>
<span class="Delimiter">}</span>

<span class="Delimiter">:(code)</span>
vector&lt;<span class="Normal">double</span>&gt; deep_copy<span class="Delimiter">(</span><span class="Normal">const</span> reagent&amp; in<span class="Delimiter">,</span> <span class="Normal">const</span> reagent&amp; tmp<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  map&lt;<span class="Normal">int</span><span class="Delimiter">,</span> <span class="Normal">int</span>&gt; addresses_copied<span class="Delimiter">;</span>
  <span class="Identifier">return</span> deep_copy<span class="Delimiter">(</span>in<span class="Delimiter">,</span> addresses_copied<span class="Delimiter">,</span> tmp<span class="Delimiter">);</span>
<span class="Delimiter">}</span>

vector&lt;<span class="Normal">double</span>&gt; deep_copy<span class="Delimiter">(</span>reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> in<span class="Delimiter">,</span> map&lt;<span class="Normal">int</span><span class="Delimiter">,</span> <span class="Normal">int</span>&gt;&amp; addresses_copied<span class="Delimiter">,</span> <span class="Normal">const</span> reagent&amp; tmp<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  canonize<span class="Delimiter">(</span>in<span class="Delimiter">);</span>
  vector&lt;<span class="Normal">double</span>&gt; result<span class="Delimiter">;</span>
  <span class="Normal">if</span> <span class="Delimiter">(</span>is_mu_address<span class="Delimiter">(</span>in<span class="Delimiter">))</span>
    result<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>deep_copy_address<span class="Delimiter">(</span>in<span class="Delimiter">,</span> addresses_copied<span class="Delimiter">,</span> tmp<span class="Delimiter">));</span>
  <span class="Normal">else</span>
    deep_copy<span class="Delimiter">(</span>in<span class="Delimiter">,</span> addresses_copied<span class="Delimiter">,</span> tmp<span class="Delimiter">,</span> result<span class="Delimiter">);</span>
  <span class="Identifier">return</span> result<span class="Delimiter">;</span>
<span class="Delimiter">}</span>

<span class="Comment">// deep-copy an address and return a new address</span>
<span class="Normal">int</span> deep_copy_address<span class="Delimiter">(</span><span class="Normal">const</span> reagent&amp; canonized_in<span class="Delimiter">,</span> map&lt;<span class="Normal">int</span><span class="Delimiter">,</span> <span class="Normal">int</span>&gt;&amp; addresses_copied<span class="Delimiter">,</span> <span class="Normal">const</span> reagent&amp; tmp<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  <span class="Normal">if</span> <span class="Delimiter">(</span>canonized_in<span class="Delimiter">.</span>value == <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Identifier">return</span> <span class="Constant">0</span><span class="Delimiter">;</span>
  <span class="Normal">int</span> in_address = payload_address<span class="Delimiter">(</span>canonized_in<span class="Delimiter">);</span>
  trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;deep-copy: copying address &quot;</span> &lt;&lt; in_address &lt;&lt; end<span class="Delimiter">();</span>
  <span class="Normal">if</span> <span class="Delimiter">(</span>contains_key<span class="Delimiter">(</span>addresses_copied<span class="Delimiter">,</span> in_address<span class="Delimiter">))</span> <span class="Delimiter">{</span>
    <span class="Normal">int</span> out = get<span class="Delimiter">(</span>addresses_copied<span class="Delimiter">,</span> in_address<span class="Delimiter">);</span>
    trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;deep-copy: copy already exists: &quot;</span> &lt;&lt; out &lt;&lt; end<span class="Delimiter">();</span>
    <span class="Identifier">return</span> out<span class="Delimiter">;</span>
  <span class="Delimiter">}</span>
  <span class="Normal">int</span> out = allocate<span class="Delimiter">(</span>payload_size<span class="Delimiter">(</span>canonized_in<span class="Delimiter">));</span>
  trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;deep-copy: new address is &quot;</span> &lt;&lt; out &lt;&lt; end<span class="Delimiter">();</span>
  put<span class="Delimiter">(</span>addresses_copied<span class="Delimiter">,</span> in_address<span class="Delimiter">,</span> out<span class="Delimiter">);</span>
  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> payload = canonized_in<span class="Delimiter">;</span>
  payload<span class="Delimiter">.</span>properties<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>pair&lt;string<span class="Delimiter">,</span> string_tree*&gt;<span class="Delimiter">(</span><span class="Constant">&quot;lookup&quot;</span><span class="Delimiter">,</span> <span class="Constant">NULL</span><span class="Delimiter">));</span>
  trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;recursing on payload &quot;</span> &lt;&lt; payload<span class="Delimiter">.</span>value &lt;&lt; <span class="Constant">' '</span> &lt;&lt; to_string<span class="Delimiter">(</span>payload<span class="Delimiter">)</span> &lt;&lt; end<span class="Delimiter">();</span>
  vector&lt;<span class="Normal">double</span>&gt; data = deep_copy<span class="Delimiter">(</span>payload<span class="Delimiter">,</span> addresses_copied<span class="Delimiter">,</span> tmp<span class="Delimiter">);</span>
  trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;deep-copy: writing result &quot;</span> &lt;&lt; out &lt;&lt; <span class="Constant">&quot;: &quot;</span> &lt;&lt; to_string<span class="Delimiter">(</span>data<span class="Delimiter">)</span> &lt;&lt; end<span class="Delimiter">();</span>
  <span class="Comment">// HACK: write_memory interface isn't ideal for this situation; we need</span>
  <span class="Comment">// a temporary location to help copy the payload.</span>
  trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;deep-copy: writing temporary &quot;</span> &lt;&lt; tmp<span class="Delimiter">.</span>value &lt;&lt; <span class="Constant">&quot;: &quot;</span> &lt;&lt; out &lt;&lt; end<span class="Delimiter">();</span>
  put<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> tmp<span class="Delimiter">.</span>value<span class="Delimiter">,</span> out<span class="Delimiter">);</span>
  payload<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span>tmp<span class="Delimiter">.</span>value<span class="Delimiter">);</span>  <span class="Comment">// now modified for output</span>
  vector&lt;<span class="Normal">double</span>&gt; old_data = read_memory<span class="Delimiter">(</span>payload<span class="Delimiter">);</span>
  trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;deep-copy: really writing to &quot;</span> &lt;&lt; payload<span class="Delimiter">.</span>value &lt;&lt; <span class="Constant">' '</span> &lt;&lt; to_string<span class="Delimiter">(</span>payload<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot; (old value &quot;</span> &lt;&lt; to_string<span class="Delimiter">(</span>old_data<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot; new value &quot;</span> &lt;&lt; to_string<span class="Delimiter">(</span>data<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;)&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
  write_memory<span class="Delimiter">(</span>payload<span class="Delimiter">,</span> data<span class="Delimiter">);</span>
  trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;deep-copy: output is &quot;</span> &lt;&lt; to_string<span class="Delimiter">(</span>data<span class="Delimiter">)</span> &lt;&lt; end<span class="Delimiter">();</span>
  <span class="Identifier">return</span> out<span class="Delimiter">;</span>
<span class="Delimiter">}</span>

<span class="Comment">// deep-copy a non-address and return a vector of locations</span>
<span class="Normal">void</span> deep_copy<span class="Delimiter">(</span><span class="Normal">const</span> reagent&amp; canonized_in<span class="Delimiter">,</span> map&lt;<span class="Normal">int</span><span class="Delimiter">,</span> <span class="Normal">int</span>&gt;&amp; addresses_copied<span class="Delimiter">,</span> <span class="Normal">const</span> reagent&amp; tmp<span class="Delimiter">,</span> vector&lt;<span class="Normal">double</span>&gt;&amp; out<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  assert<span class="Delimiter">(</span>!is_mu_address<span class="Delimiter">(</span>canonized_in<span class="Delimiter">));</span>
  vector&lt;<span class="Normal">double</span>&gt; data = read_memory<span class="Delimiter">(</span>canonized_in<span class="Delimiter">);</span>
  out<span class="Delimiter">.</span>insert<span class="Delimiter">(</span>out<span class="Delimiter">.</span>end<span class="Delimiter">(),</span> data<span class="Delimiter">.</span>begin<span class="Delimiter">(),</span> data<span class="Delimiter">.</span>end<span class="Delimiter">());</span>
  <span class="Normal">if</span> <span class="Delimiter">(</span>!contains_key<span class="Delimiter">(</span>Container_metadata<span class="Delimiter">,</span> canonized_in<span class="Delimiter">.</span>type<span class="Delimiter">))</span> <span class="Identifier">return</span><span class="Delimiter">;</span>
  trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;deep-copy: scanning for addresses in &quot;</span> &lt;&lt; to_string<span class="Delimiter">(</span>data<span class="Delimiter">)</span> &lt;&lt; end<span class="Delimiter">();</span>
  <span class="Normal">const</span> container_metadata&amp; metadata = get<span class="Delimiter">(</span>Container_metadata<span class="Delimiter">,</span> canonized_in<span class="Delimiter">.</span>type<span class="Delimiter">);</span>
  <span class="Normal">for</span> <span class="Delimiter">(</span>map&lt;set&lt;tag_condition_info&gt;<span class="Delimiter">,</span> set&lt;address_element_info&gt; &gt;::const_iterator p = metadata<span class="Delimiter">.</span>address<span class="Delimiter">.</span>begin<span class="Delimiter">();</span> p != metadata<span class="Delimiter">.</span>address<span class="Delimiter">.</span>end<span class="Delimiter">();</span> ++p<span class="Delimiter">)</span> <span class="Delimiter">{</span>
    <span class="Normal">if</span> <span class="Delimiter">(</span>!all_match<span class="Delimiter">(</span>data<span class="Delimiter">,</span> p<span class="Delimiter">-&gt;</span>first<span class="Delimiter">))</span> <span class="Identifier">continue</span><span class="Delimiter">;</span>
    <span class="Normal">for</span> <span class="Delimiter">(</span>set&lt;address_element_info&gt;::const_iterator info = p<span class="Delimiter">-&gt;</span>second<span class="Delimiter">.</span>begin<span class="Delimiter">();</span> info != p<span class="Delimiter">-&gt;</span>second<span class="Delimiter">.</span>end<span class="Delimiter">();</span> ++info<span class="Delimiter">)</span> <span class="Delimiter">{</span>
      <span class="Comment">// construct a fake reagent that reads directly from the appropriate</span>
      <span class="Comment">// field of the container</span>
      reagent curr<span class="Delimiter">;</span>
      curr<span class="Delimiter">.</span>type = <span class="Normal">new</span> type_tree<span class="Delimiter">(</span><span class="Normal">new</span> type_tree<span class="Delimiter">(</span><span class="Constant">&quot;address&quot;</span><span class="Delimiter">),</span> <span class="Normal">new</span> type_tree<span class="Delimiter">(</span>*info<span class="Delimiter">-&gt;</span>payload_type<span class="Delimiter">));</span>
      curr<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span>canonized_in<span class="Delimiter">.</span>value + info<span class="Delimiter">-&gt;</span>offset<span class="Delimiter">);</span>
      curr<span class="Delimiter">.</span>properties<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>pair&lt;string<span class="Delimiter">,</span> string_tree*&gt;<span class="Delimiter">(</span><span class="Constant">&quot;raw&quot;</span><span class="Delimiter">,</span> <span class="Constant">NULL</span><span class="Delimiter">));</span>
      trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;deep-copy: copying address &quot;</span> &lt;&lt; curr<span class="Delimiter">.</span>value &lt;&lt; end<span class="Delimiter">();</span>
      out<span class="Delimiter">.</span>at<span class="Delimiter">(</span>info<span class="Delimiter">-&gt;</span>offset<span class="Delimiter">)</span> = deep_copy_address<span class="Delimiter">(</span>curr<span class="Delimiter">,</span> addresses_copied<span class="Delimiter">,</span> tmp<span class="Delimiter">);</span>
    <span class="Delimiter">}</span>
  <span class="Delimiter">}</span>
<span class="Delimiter">}</span>

<span class="Normal">int</span> payload_address<span class="Delimiter">(</span>reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> x<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  x<span class="Delimiter">.</span>properties<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>pair&lt;string<span class="Delimiter">,</span> string_tree*&gt;<span class="Delimiter">(</span><span class="Constant">&quot;lookup&quot;</span><span class="Delimiter">,</span> <span class="Constant">NULL</span><span class="Delimiter">));</span>
  canonize<span class="Delimiter">(</span>x<span class="Delimiter">);</span>
  <span class="Identifier">return</span> x<span class="Delimiter">.</span>value<span class="Delimiter">;</span>
<span class="Delimiter">}</span>

<span class="Comment">//: moar tests, just because I can't believe it all works</span>

<span class="Delimiter">:(scenario deep_copy_stress_test_1)</span>
container foo1 [
  <span class="Normal">p</span>:&amp;:num
]
container foo2 [
  <span class="Normal">p</span>:&amp;:foo1
]
exclusive-container foo3 [
  <span class="Normal">p</span>:&amp;:foo1
  <span class="Normal">q</span>:&amp;:foo2
]
def main [
  local-scope
  <span class="Normal">x</span>:&amp;:num<span class="Special"> &lt;- </span><span class="Normal">new</span> number:type
  *x<span class="Special"> &lt;- </span>copy <span class="Constant">34</span>
  <span class="Normal">a</span>:&amp;:foo1<span class="Special"> &lt;- </span><span class="Normal">new</span> foo1:type
  *a<span class="Special"> &lt;- </span>merge x
  <span class="Normal">b</span>:&amp;:foo2<span class="Special"> &lt;- </span><span class="Normal">new</span> foo2:type
  *b<span class="Special"> &lt;- </span>merge a
  <span class="Normal">c</span>:foo3<span class="Special"> &lt;- </span>merge <span class="Constant">1</span>/q<span class="Delimiter">,</span> b
  <span class="Normal">d</span>:foo3<span class="Special"> &lt;- </span>deep-copy c
  <span class="Normal">e</span>:&amp;:foo2<span class="Delimiter">,</span> z:<span class="Normal">bool</span><span class="Special"> &lt;- </span>maybe-convert d<span class="Delimiter">,</span> q:variant
  <span class="Normal">f</span>:&amp;:foo1<span class="Special"> &lt;- </span>get *e<span class="Delimiter">,</span> p:offset
  <span class="Normal">g</span>:&amp;:num<span class="Special"> &lt;- </span>get *f<span class="Delimiter">,</span> p:offset
  <span class="Constant">1</span>:num/<span class="Special">raw &lt;- </span>copy *g
]
<span class="traceContains">+mem: storing 34 in location 1</span>

<span class="Delimiter">:(scenario deep_copy_stress_test_2)</span>
container foo1 [
  <span class="Normal">p</span>:&amp;:num
]
container foo2 [
  <span class="Normal">p</span>:&amp;:foo1
]
exclusive-container foo3 [
  <span class="Normal">p</span>:&amp;:foo1
  <span class="Normal">q</span>:&amp;:foo2
]
container foo4 [
  <span class="Normal">p</span>:num
  <span class="Normal">q</span>:&amp;:foo3
]
def main [
  local-scope
  <span class="Normal">x</span>:&amp;:num<span class="Special"> &lt;- </span><span class="Normal">new</span> number:type
  *x<span class="Special"> &lt;- </span>copy <span class="Constant">34</span>
  <span class="Normal">a</span>:&amp;:foo1<span class="Special"> &lt;- </span><span class="Normal">new</span> foo1:type
  *a<span class="Special"> &lt;- </span>merge x
  <span class="Normal">b</span>:&amp;:foo2<span class="Special"> &lt;- </span><span class="Normal">new</span> foo2:type
  *b<span class="Special"> &lt;- </span>merge a
  <span class="Normal">c</span>:&amp;:foo3<span class="Special"> &lt;- </span><span class="Normal">new</span> foo3:type
  *c<span class="Special"> &lt;- </span>merge <span class="Constant">1</span>/q<span class="Delimiter">,</span> b
  <span class="Normal">d</span>:foo4<span class="Special"> &lt;- </span>merge <span class="Constant">35</span><span class="Delimiter">,</span> c
  <span class="Normal">e</span>:foo4<span class="Special"> &lt;- </span>deep-copy d
  <span class="Normal">f</span>:&amp;:foo3<span class="Special"> &lt;- </span>get e<span class="Delimiter">,</span> q:offset
  <span class="Normal">g</span>:&amp;:foo2<span class="Delimiter">,</span> z:<span class="Normal">bool</span><span class="Special"> &lt;- </span>maybe-convert *f<span class="Delimiter">,</span> q:variant
  <span class="Normal">h</span>:&amp;:foo1<span class="Special"> &lt;- </span>get *g<span class="Delimiter">,</span> p:offset
  <span class="Normal">y</span>:&amp;:num<span class="Special"> &lt;- </span>get *h<span class="Delimiter">,</span> p:offset
  <span class="Constant">1</span>:num/<span class="Special">raw &lt;- </span>copy *y
]
<span class="traceContains">+mem: storing 34 in location 1</span>

<span class="Delimiter">:(scenario deep_copy_cycles)</span>
container foo [
  <span class="Normal">p</span>:num
  <span class="Normal">q</span>:&amp;:foo
]
def main [
  local-scope
  <span class="Normal">x</span>:&amp;:foo<span class="Special"> &lt;- </span><span class="Normal">new</span> foo:type
  *x<span class="Special"> &lt;- </span>put *x<span class="Delimiter">,</span> p:offset<span class="Delimiter">,</span> <span class="Constant">34</span>
  *x<span class="Special"> &lt;- </span>put *x<span class="Delimiter">,</span> q:offset<span class="Delimiter">,</span> x  <span class="Comment"># create a cycle</span>
  <span class="Normal">y</span>:&amp;:foo<span class="Special"> &lt;- </span>deep-copy x
  <span class="Constant">1</span>:num/<span class="Special">raw &lt;- </span>get *y<span class="Delimiter">,</span> p:offset
  <span class="Normal">y2</span>:&amp;:foo<span class="Special"> &lt;- </span>get *y<span class="Delimiter">,</span> q:offset
  stash y [vs] y2
  <span class="Constant">2</span>:<span class="Normal">bool</span>/<span class="Special">raw &lt;- </span>equal y<span class="Delimiter">,</span> y2  <span class="Comment"># is it still a cycle?</span>
  <span class="Constant">3</span>:<span class="Normal">bool</span>/<span class="Special">raw &lt;- </span>equal x<span class="Delimiter">,</span> y  <span class="Comment"># is it the same cycle?</span>
]
<span class="traceContains">+mem: storing 34 in location 1</span>
<span class="Comment"># deep copy also contains a cycle</span>
<span class="traceContains">+mem: storing 1 in location 2</span>
<span class="Comment"># but it's a completely different (disjoint) cycle</span>
<span class="traceContains">+mem: storing 0 in location 3</span>
</pre>
</body>
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