<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Mu - 069hash.cc</title> <meta name="Generator" content="Vim/7.4"> <meta name="plugin-version" content="vim7.4_v2"> <meta name="syntax" content="cpp"> <meta name="settings" content="use_css,pre_wrap,no_foldcolumn,expand_tabs,prevent_copy="> <meta name="colorscheme" content="minimal"> <style type="text/css"> <!-- pre { white-space: pre-wrap; font-family: monospace; color: #eeeeee; background-color: #080808; } body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color: #080808; } * { font-size: 12pt; font-size: 1em; } .Constant { color: #00a0a0; } .Special { color: #c00000; } .traceContains { color: #008000; } .Comment { color: #9090ff; } .Delimiter { color: #800080; } .cSpecial { color: #008000; } .Identifier { color: #fcb165; } .Normal { color: #eeeeee; background-color: #080808; padding-bottom: 1px; } .CommentedCode { color: #6c6c6c; } --> </style> <script type='text/javascript'> <!-- --> </script> </head> <body> <pre id='vimCodeElement'> <span class="Comment">// A universal hash function that can handle objects of any type.</span> <span class="Comment">//</span> <span class="Comment">// The way it's currently implemented, two objects will have the same hash if</span> <span class="Comment">// all their non-address fields (all the way down) expand to the same sequence</span> <span class="Comment">// of scalar values. In particular, a container with all zero addresses hashes</span> <span class="Comment">// to 0. Hopefully this won't be an issue because we are usually hashing</span> <span class="Comment">// objects of a single type in any given hash table.</span> <span class="Comment">//</span> <span class="Comment">// Based on <a href="http://burtleburtle.net/bob/hash/hashfaq.html">http://burtleburtle.net/bob/hash/hashfaq.html</a></span> <span class="Delimiter">:(before "End Primitive Recipe Declarations")</span> HASH<span class="Delimiter">,</span> <span class="Delimiter">:(before "End Primitive Recipe Numbers")</span> put<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">"hash"</span><span class="Delimiter">,</span> HASH<span class="Delimiter">);</span> <span class="Delimiter">:(before "End Primitive Recipe Checks")</span> <span class="Normal">case</span> HASH: <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 << 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> << <span class="Constant">"'hash' takes exactly one ingredient rather than '"</span> << inst<span class="Delimiter">.</span>original_string << <span class="Constant">"'</span><span class="cSpecial">\n</span><span class="Constant">"</span> << 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 "End Primitive Recipe Implementations")</span> <span class="Normal">case</span> HASH: <span class="Delimiter">{</span> <span class="Normal">const</span> reagent& 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> products<span class="Delimiter">.</span>resize<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">);</span> products<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>push_back<span class="Delimiter">(</span>hash<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">,</span> input<span class="Delimiter">));</span> <span class="Identifier">break</span><span class="Delimiter">;</span> <span class="Delimiter">}</span> <span class="Comment">//: in all the code below, the intermediate results of hashing are threaded through 'h'</span> <span class="Delimiter">:(code)</span> <span class="Normal">size_t</span> hash<span class="Delimiter">(</span><span class="Normal">size_t</span> h<span class="Delimiter">,</span> reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> r<span class="Delimiter">)</span> <span class="Delimiter">{</span> canonize<span class="Delimiter">(</span>r<span class="Delimiter">);</span> <span class="Normal">if</span> <span class="Delimiter">(</span>is_mu_string<span class="Delimiter">(</span>r<span class="Delimiter">))</span> <span class="Comment">// optimization</span> <span class="Identifier">return</span> hash_mu_string<span class="Delimiter">(</span>h<span class="Delimiter">,</span> r<span class="Delimiter">);</span> <span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>is_mu_address<span class="Delimiter">(</span>r<span class="Delimiter">))</span> <span class="Identifier">return</span> hash_mu_address<span class="Delimiter">(</span>h<span class="Delimiter">,</span> r<span class="Delimiter">);</span> <span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>is_mu_scalar<span class="Delimiter">(</span>r<span class="Delimiter">))</span> <span class="Identifier">return</span> hash_mu_scalar<span class="Delimiter">(</span>h<span class="Delimiter">,</span> r<span class="Delimiter">);</span> <span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>is_mu_array<span class="Delimiter">(</span>r<span class="Delimiter">))</span> <span class="Identifier">return</span> hash_mu_array<span class="Delimiter">(</span>h<span class="Delimiter">,</span> r<span class="Delimiter">);</span> <span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>is_mu_container<span class="Delimiter">(</span>r<span class="Delimiter">))</span> <span class="Identifier">return</span> hash_mu_container<span class="Delimiter">(</span>h<span class="Delimiter">,</span> r<span class="Delimiter">);</span> <span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>is_mu_exclusive_container<span class="Delimiter">(</span>r<span class="Delimiter">))</span> <span class="Identifier">return</span> hash_mu_exclusive_container<span class="Delimiter">(</span>h<span class="Delimiter">,</span> r<span class="Delimiter">);</span> assert<span class="Delimiter">(</span><span class="Constant">false</span><span class="Delimiter">);</span> <span class="Delimiter">}</span> <span class="Normal">size_t</span> hash_mu_scalar<span class="Delimiter">(</span><span class="Normal">size_t</span> h<span class="Delimiter">,</span> <span class="Normal">const</span> reagent& r<span class="Delimiter">)</span> <span class="Delimiter">{</span> <span class="Normal">double</span> input = is_literal<span class="Delimiter">(</span>r<span class="Delimiter">)</span> ? r<span class="Delimiter">.</span>value : get_or_insert<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> r<span class="Delimiter">.</span>value<span class="Delimiter">);</span> <span class="Identifier">return</span> hash_iter<span class="Delimiter">(</span>h<span class="Delimiter">,</span> <span class="Normal">static_cast</span><<span class="Normal">size_t</span>><span class="Delimiter">(</span>input<span class="Delimiter">));</span> <span class="Delimiter">}</span> <span class="Normal">size_t</span> hash_mu_address<span class="Delimiter">(</span><span class="Normal">size_t</span> h<span class="Delimiter">,</span> reagent& r<span class="Delimiter">)</span> <span class="Delimiter">{</span> <span class="Normal">if</span> <span class="Delimiter">(</span>r<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> trace<span class="Delimiter">(</span><span class="Constant">9999</span><span class="Delimiter">,</span> <span class="Constant">"mem"</span><span class="Delimiter">)</span> << <span class="Constant">"location "</span> << r<span class="Delimiter">.</span>value << <span class="Constant">" is "</span> << no_scientific<span class="Delimiter">(</span>get_or_insert<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> r<span class="Delimiter">.</span>value<span class="Delimiter">))</span> << end<span class="Delimiter">();</span> r<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span>get_or_insert<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> r<span class="Delimiter">.</span>value<span class="Delimiter">));</span> <span class="Normal">if</span> <span class="Delimiter">(</span>r<span class="Delimiter">.</span>value != <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Delimiter">{</span> trace<span class="Delimiter">(</span><span class="Constant">9999</span><span class="Delimiter">,</span> <span class="Constant">"mem"</span><span class="Delimiter">)</span> << <span class="Constant">"skipping refcount at "</span> << r<span class="Delimiter">.</span>value << end<span class="Delimiter">();</span> r<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span>r<span class="Delimiter">.</span>value+<span class="Constant">1</span><span class="Delimiter">);</span> <span class="Comment">// skip refcount</span> <span class="Delimiter">}</span> drop_from_type<span class="Delimiter">(</span>r<span class="Delimiter">,</span> <span class="Constant">"address"</span><span class="Delimiter">);</span> <span class="Identifier">return</span> hash<span class="Delimiter">(</span>h<span class="Delimiter">,</span> r<span class="Delimiter">);</span> <span class="Delimiter">}</span> <span class="Normal">size_t</span> hash_mu_string<span class="Delimiter">(</span><span class="Normal">size_t</span> h<span class="Delimiter">,</span> <span class="Normal">const</span> reagent& r<span class="Delimiter">)</span> <span class="Delimiter">{</span> string input = read_mu_string<span class="Delimiter">(</span>get_or_insert<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> r<span class="Delimiter">.</span>value<span class="Delimiter">));</span> <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">0</span><span class="Delimiter">;</span> i < SIZE<span class="Delimiter">(</span>input<span class="Delimiter">);</span> ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span> h = hash_iter<span class="Delimiter">(</span>h<span class="Delimiter">,</span> <span class="Normal">static_cast</span><<span class="Normal">size_t</span>><span class="Delimiter">(</span>input<span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">)));</span> <span class="CommentedCode">//? cerr << i << ": " << h << '\n';</span> <span class="Delimiter">}</span> <span class="Identifier">return</span> h<span class="Delimiter">;</span> <span class="Delimiter">}</span> <span class="Normal">size_t</span> hash_mu_array<span class="Delimiter">(</span><span class="Normal">size_t</span> h<span class="Delimiter">,</span> <span class="Normal">const</span> reagent& r<span class="Delimiter">)</span> <span class="Delimiter">{</span> <span class="Normal">int</span> size = get_or_insert<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> r<span class="Delimiter">.</span>value<span class="Delimiter">);</span> reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> elem = r<span class="Delimiter">;</span> <span class="Normal">delete</span> elem<span class="Delimiter">.</span>type<span class="Delimiter">;</span> elem<span class="Delimiter">.</span>type = copy_array_element<span class="Delimiter">(</span>r<span class="Delimiter">.</span>type<span class="Delimiter">);</span> <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i=<span class="Constant">0</span><span class="Delimiter">,</span> address = r<span class="Delimiter">.</span>value+<span class="Constant">1</span><span class="Delimiter">;</span> i < size<span class="Delimiter">;</span> ++i<span class="Delimiter">,</span> address += size_of<span class="Delimiter">(</span>elem<span class="Delimiter">))</span> <span class="Delimiter">{</span> reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> tmp = elem<span class="Delimiter">;</span> tmp<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span>address<span class="Delimiter">);</span> h = hash<span class="Delimiter">(</span>h<span class="Delimiter">,</span> tmp<span class="Delimiter">);</span> <span class="CommentedCode">//? cerr << i << " (" << address << "): " << h << '\n';</span> <span class="Delimiter">}</span> <span class="Identifier">return</span> h<span class="Delimiter">;</span> <span class="Delimiter">}</span> <span class="Normal">size_t</span> hash_mu_container<span class="Delimiter">(</span><span class="Normal">size_t</span> h<span class="Delimiter">,</span> <span class="Normal">const</span> reagent& r<span class="Delimiter">)</span> <span class="Delimiter">{</span> assert<span class="Delimiter">(</span>r<span class="Delimiter">.</span>type<span class="Delimiter">-></span>value<span class="Delimiter">);</span> type_info& info = get<span class="Delimiter">(</span>Type<span class="Delimiter">,</span> r<span class="Delimiter">.</span>type<span class="Delimiter">-></span>value<span class="Delimiter">);</span> <span class="Normal">int</span> address = r<span class="Delimiter">.</span>value<span class="Delimiter">;</span> <span class="Normal">int</span> offset = <span class="Constant">0</span><span class="Delimiter">;</span> <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">0</span><span class="Delimiter">;</span> i < SIZE<span class="Delimiter">(</span>info<span class="Delimiter">.</span>elements<span class="Delimiter">);</span> ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span> reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> element = element_type<span class="Delimiter">(</span>r<span class="Delimiter">.</span>type<span class="Delimiter">,</span> i<span class="Delimiter">);</span> <span class="Normal">if</span> <span class="Delimiter">(</span>has_property<span class="Delimiter">(</span>element<span class="Delimiter">,</span> <span class="Constant">"ignore-for-hash"</span><span class="Delimiter">))</span> <span class="Identifier">continue</span><span class="Delimiter">;</span> element<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span>address+offset<span class="Delimiter">);</span> h = hash<span class="Delimiter">(</span>h<span class="Delimiter">,</span> element<span class="Delimiter">);</span> <span class="CommentedCode">//? cerr << i << ": " << h << '\n';</span> offset += size_of<span class="Delimiter">(</span>info<span class="Delimiter">.</span>elements<span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">).</span>type<span class="Delimiter">);</span> <span class="Delimiter">}</span> <span class="Identifier">return</span> h<span class="Delimiter">;</span> <span class="Delimiter">}</span> <span class="Normal">size_t</span> hash_mu_exclusive_container<span class="Delimiter">(</span><span class="Normal">size_t</span> h<span class="Delimiter">,</span> <span class="Normal">const</span> reagent& r<span class="Delimiter">)</span> <span class="Delimiter">{</span> assert<span class="Delimiter">(</span>r<span class="Delimiter">.</span>type<span class="Delimiter">-></span>value<span class="Delimiter">);</span> <span class="Normal">int</span> tag = get<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> r<span class="Delimiter">.</span>value<span class="Delimiter">);</span> reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> variant = variant_type<span class="Delimiter">(</span>r<span class="Delimiter">,</span> tag<span class="Delimiter">);</span> <span class="Comment">// todo: move this error to container definition time</span> <span class="Normal">if</span> <span class="Delimiter">(</span>has_property<span class="Delimiter">(</span>variant<span class="Delimiter">,</span> <span class="Constant">"ignore-for-hash"</span><span class="Delimiter">))</span> raise << get<span class="Delimiter">(</span>Type<span class="Delimiter">,</span> r<span class="Delimiter">.</span>type<span class="Delimiter">-></span>value<span class="Delimiter">).</span>name << <span class="Constant">": /ignore-for-hash won't work in exclusive containers</span><span class="cSpecial">\n</span><span class="Constant">"</span> << end<span class="Delimiter">();</span> variant<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span>r<span class="Delimiter">.</span>value + <span class="Comment">/*</span><span class="Comment">skip tag</span><span class="Comment">*/</span><span class="Constant">1</span><span class="Delimiter">);</span> h = hash<span class="Delimiter">(</span>h<span class="Delimiter">,</span> variant<span class="Delimiter">);</span> <span class="Identifier">return</span> h<span class="Delimiter">;</span> <span class="Delimiter">}</span> <span class="Normal">size_t</span> hash_iter<span class="Delimiter">(</span><span class="Normal">size_t</span> h<span class="Delimiter">,</span> <span class="Normal">size_t</span> input<span class="Delimiter">)</span> <span class="Delimiter">{</span> h += input<span class="Delimiter">;</span> h += <span class="Delimiter">(</span>h<<<span class="Constant">10</span><span class="Delimiter">);</span> h ^= <span class="Delimiter">(</span>h>><span class="Constant">6</span><span class="Delimiter">);</span> h += <span class="Delimiter">(</span>h<<<span class="Constant">3</span><span class="Delimiter">);</span> h ^= <span class="Delimiter">(</span>h>><span class="Constant">11</span><span class="Delimiter">);</span> h += <span class="Delimiter">(</span>h<<<span class="Constant">15</span><span class="Delimiter">);</span> <span class="Identifier">return</span> h<span class="Delimiter">;</span> <span class="Delimiter">}</span> <span class="Delimiter">:(scenario hash_container_checks_all_elements)</span> container foo [ <span class="Normal">x</span>:number <span class="Normal">y</span>:character ] def main [ <span class="Constant">1</span>:foo<span class="Special"> <- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">97</span>/a <span class="Constant">3</span>:number<span class="Special"> <- </span>hash <span class="Constant">1</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">3</span>:number <span class="Constant">4</span>:foo<span class="Special"> <- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">98</span>/a <span class="Constant">6</span>:number<span class="Special"> <- </span>hash <span class="Constant">4</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">6</span>:number <span class="Constant">7</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">3</span>:number<span class="Delimiter">,</span> <span class="Constant">6</span>:number ] <span class="Comment"># hash on containers includes all elements</span> <span class="traceContains">+mem: storing 0 in location 7</span> <span class="Delimiter">:(scenario hash_exclusive_container_checks_all_elements)</span> exclusive-container foo [ <span class="Normal">x</span>:bar <span class="Normal">y</span>:number ] container bar [ <span class="Normal">a</span>:number <span class="Normal">b</span>:number ] def main [ <span class="Constant">1</span>:foo<span class="Special"> <- </span>merge <span class="Constant">0</span>/x<span class="Delimiter">,</span> <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">35</span> <span class="Constant">4</span>:number<span class="Special"> <- </span>hash <span class="Constant">1</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">4</span>:number <span class="Constant">5</span>:foo<span class="Special"> <- </span>merge <span class="Constant">0</span>/x<span class="Delimiter">,</span> <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">36</span> <span class="Constant">8</span>:number<span class="Special"> <- </span>hash <span class="Constant">5</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">8</span>:number <span class="Constant">9</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">4</span>:number<span class="Delimiter">,</span> <span class="Constant">8</span>:number ] <span class="Comment"># hash on containers includes all elements</span> <span class="traceContains">+mem: storing 0 in location 9</span> <span class="Delimiter">:(scenario hash_can_ignore_container_elements)</span> container foo [ <span class="Normal">x</span>:number <span class="Normal">y</span>:character/ignore-<span class="Normal">for</span>-hash ] def main [ <span class="Constant">1</span>:foo<span class="Special"> <- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">97</span>/a <span class="Constant">3</span>:number<span class="Special"> <- </span>hash <span class="Constant">1</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">3</span>:number <span class="Constant">4</span>:foo<span class="Special"> <- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">98</span>/a <span class="Constant">6</span>:number<span class="Special"> <- </span>hash <span class="Constant">4</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">6</span>:number <span class="Constant">7</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">3</span>:number<span class="Delimiter">,</span> <span class="Constant">6</span>:number ] <span class="Comment"># hashes match even though y is different</span> <span class="traceContains">+mem: storing 1 in location 7</span> <span class="Comment">//: These properties aren't necessary for hash, they just test that the</span> <span class="Comment">//: current implementation works like we think it does.</span> <span class="Delimiter">:(scenario hash_of_zero_address)</span> def main [ <span class="Constant">1</span>:address:number<span class="Special"> <- </span>copy <span class="Constant">0</span> <span class="Constant">2</span>:number<span class="Special"> <- </span>hash <span class="Constant">1</span>:address:number ] <span class="traceContains">+mem: storing 0 in location 2</span> <span class="Comment">//: This is probably too aggressive, but we need some way to avoid depending</span> <span class="Comment">//: on the precise bit pattern of a floating-point number.</span> <span class="Delimiter">:(scenario hash_of_numbers_ignores_fractional_part)</span> def main [ <span class="Constant">1</span>:number<span class="Special"> <- </span>hash <span class="Constant">1.5</span> <span class="Constant">2</span>:number<span class="Special"> <- </span>hash <span class="Constant">1</span> <span class="Constant">3</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">1</span>:number<span class="Delimiter">,</span> <span class="Constant">2</span>:number ] <span class="traceContains">+mem: storing 1 in location 3</span> <span class="Delimiter">:(scenario hash_of_array_same_as_string)</span> def main [ <span class="Constant">10</span>:number<span class="Special"> <- </span>copy <span class="Constant">3</span> <span class="Constant">11</span>:number<span class="Special"> <- </span>copy <span class="Constant">97</span> <span class="Constant">12</span>:number<span class="Special"> <- </span>copy <span class="Constant">98</span> <span class="Constant">13</span>:number<span class="Special"> <- </span>copy <span class="Constant">99</span> <span class="Constant">2</span>:number<span class="Special"> <- </span>hash <span class="Constant">10</span>:array:number/unsafe <span class="Identifier">return</span>-unless <span class="Constant">2</span>:number <span class="Constant">3</span>:address:array:character<span class="Special"> <- </span><span class="Normal">new</span> [abc] <span class="Constant">4</span>:number<span class="Special"> <- </span>hash <span class="Constant">3</span>:address:array:character <span class="Identifier">return</span>-unless <span class="Constant">4</span>:number <span class="Constant">5</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">2</span>:number<span class="Delimiter">,</span> <span class="Constant">4</span>:number ] <span class="traceContains">+mem: storing 1 in location 5</span> <span class="Delimiter">:(scenario hash_ignores_address_value)</span> def main [ <span class="Constant">1</span>:address:number<span class="Special"> <- </span><span class="Normal">new</span> number:type *<span class="Constant">1</span>:address:number<span class="Special"> <- </span>copy <span class="Constant">34</span> <span class="Constant">2</span>:number<span class="Special"> <- </span>hash <span class="Constant">1</span>:address:number <span class="Constant">3</span>:address:number<span class="Special"> <- </span><span class="Normal">new</span> number:type *<span class="Constant">3</span>:address:number<span class="Special"> <- </span>copy <span class="Constant">34</span> <span class="Constant">4</span>:number<span class="Special"> <- </span>hash <span class="Constant">3</span>:address:number <span class="Constant">5</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">2</span>:number<span class="Delimiter">,</span> <span class="Constant">4</span>:number ] <span class="Comment"># different addresses hash to the same result as long as the values the point to do so</span> <span class="traceContains">+mem: storing 1 in location 5</span> <span class="Delimiter">:(scenario hash_ignores_address_refcount)</span> def main [ <span class="Constant">1</span>:address:number<span class="Special"> <- </span><span class="Normal">new</span> number:type *<span class="Constant">1</span>:address:number<span class="Special"> <- </span>copy <span class="Constant">34</span> <span class="Constant">2</span>:number<span class="Special"> <- </span>hash <span class="Constant">1</span>:address:number <span class="Identifier">return</span>-unless <span class="Constant">2</span>:number <span class="Comment"># increment refcount</span> <span class="Constant">3</span>:address:number<span class="Special"> <- </span>copy <span class="Constant">1</span>:address:number <span class="Constant">4</span>:number<span class="Special"> <- </span>hash <span class="Constant">3</span>:address:number <span class="Identifier">return</span>-unless <span class="Constant">4</span>:number <span class="Constant">5</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">2</span>:number<span class="Delimiter">,</span> <span class="Constant">4</span>:number ] <span class="Comment"># hash doesn't change when refcount changes</span> <span class="traceContains">+mem: storing 1 in location 5</span> <span class="Delimiter">:(scenario hash_container_depends_only_on_elements)</span> container foo [ <span class="Normal">x</span>:number <span class="Normal">y</span>:character ] container bar [ <span class="Normal">x</span>:number <span class="Normal">y</span>:character ] def main [ <span class="Constant">1</span>:foo<span class="Special"> <- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">97</span>/a <span class="Constant">3</span>:number<span class="Special"> <- </span>hash <span class="Constant">1</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">3</span>:number <span class="Constant">4</span>:bar<span class="Special"> <- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">97</span>/a <span class="Constant">6</span>:number<span class="Special"> <- </span>hash <span class="Constant">4</span>:bar <span class="Identifier">return</span>-unless <span class="Constant">6</span>:number <span class="Constant">7</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">3</span>:number<span class="Delimiter">,</span> <span class="Constant">6</span>:number ] <span class="Comment"># containers with identical elements return identical hashes</span> <span class="traceContains">+mem: storing 1 in location 7</span> <span class="Delimiter">:(scenario hash_container_depends_only_on_elements_2)</span> container foo [ <span class="Normal">x</span>:number <span class="Normal">y</span>:character <span class="Normal">z</span>:address:number ] def main [ <span class="Constant">1</span>:address:number<span class="Special"> <- </span><span class="Normal">new</span> number:type *<span class="Constant">1</span>:address:number<span class="Special"> <- </span>copy <span class="Constant">34</span> <span class="Constant">2</span>:foo<span class="Special"> <- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">97</span>/a<span class="Delimiter">,</span> <span class="Constant">1</span>:address:number <span class="Constant">5</span>:number<span class="Special"> <- </span>hash <span class="Constant">2</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">5</span>:number <span class="Constant">6</span>:address:number<span class="Special"> <- </span><span class="Normal">new</span> number:type *<span class="Constant">6</span>:address:number<span class="Special"> <- </span>copy <span class="Constant">34</span> <span class="Constant">7</span>:foo<span class="Special"> <- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">97</span>/a<span class="Delimiter">,</span> <span class="Constant">6</span>:address:number <span class="Constant">10</span>:number<span class="Special"> <- </span>hash <span class="Constant">7</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">10</span>:number <span class="Constant">11</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">5</span>:number<span class="Delimiter">,</span> <span class="Constant">10</span>:number ] <span class="Comment"># containers with identical 'leaf' elements return identical hashes</span> <span class="traceContains">+mem: storing 1 in location 11</span> <span class="Delimiter">:(scenario hash_container_depends_only_on_elements_3)</span> container foo [ <span class="Normal">x</span>:number <span class="Normal">y</span>:character <span class="Normal">z</span>:bar ] container bar [ <span class="Normal">x</span>:number <span class="Normal">y</span>:number ] def main [ <span class="Constant">1</span>:foo<span class="Special"> <- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">97</span>/a<span class="Delimiter">,</span> <span class="Constant">47</span><span class="Delimiter">,</span> <span class="Constant">48</span> <span class="Constant">6</span>:number<span class="Special"> <- </span>hash <span class="Constant">1</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">6</span>:number <span class="Constant">7</span>:foo<span class="Special"> <- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">97</span>/a<span class="Delimiter">,</span> <span class="Constant">47</span><span class="Delimiter">,</span> <span class="Constant">48</span> <span class="Constant">12</span>:number<span class="Special"> <- </span>hash <span class="Constant">7</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">12</span>:number <span class="Constant">13</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">6</span>:number<span class="Delimiter">,</span> <span class="Constant">12</span>:number ] <span class="Comment"># containers with identical 'leaf' elements return identical hashes</span> <span class="traceContains">+mem: storing 1 in location 13</span> <span class="Delimiter">:(scenario hash_exclusive_container_ignores_tag)</span> exclusive-container foo [ <span class="Normal">x</span>:bar <span class="Normal">y</span>:number ] container bar [ <span class="Normal">a</span>:number <span class="Normal">b</span>:number ] def main [ <span class="Constant">1</span>:foo<span class="Special"> <- </span>merge <span class="Constant">0</span>/x<span class="Delimiter">,</span> <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">35</span> <span class="Constant">4</span>:number<span class="Special"> <- </span>hash <span class="Constant">1</span>:foo <span class="Identifier">return</span>-unless <span class="Constant">4</span>:number <span class="Constant">5</span>:bar<span class="Special"> <- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">35</span> <span class="Constant">7</span>:number<span class="Special"> <- </span>hash <span class="Constant">5</span>:bar <span class="Identifier">return</span>-unless <span class="Constant">7</span>:number <span class="Constant">8</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">4</span>:number<span class="Delimiter">,</span> <span class="Constant">7</span>:number ] <span class="Comment"># hash on containers includes all elements</span> <span class="traceContains">+mem: storing 1 in location 8</span> <span class="Comment">//: An older version that supported only strings.</span> <span class="Comment">//: Hash functions are subtle and easy to get wrong, so we keep the old</span> <span class="Comment">//: version around and check that the new one is consistent with it.</span> <span class="Delimiter">:(scenario hash_matches_old_version)</span> def main [ <span class="Constant">1</span>:address:array:character<span class="Special"> <- </span><span class="Normal">new</span> [abc] <span class="Constant">2</span>:number<span class="Special"> <- </span>hash <span class="Constant">1</span>:address:array:character <span class="Constant">3</span>:number<span class="Special"> <- </span>hash_old <span class="Constant">1</span>:address:array:character <span class="Constant">4</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">2</span>:number<span class="Delimiter">,</span> <span class="Constant">3</span>:number ] <span class="traceContains">+mem: storing 1 in location 4</span> <span class="Delimiter">:(before "End Primitive Recipe Declarations")</span> HASH_OLD<span class="Delimiter">,</span> <span class="Delimiter">:(before "End Primitive Recipe Numbers")</span> put<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">"hash_old"</span><span class="Delimiter">,</span> HASH_OLD<span class="Delimiter">);</span> <span class="Delimiter">:(before "End Primitive Recipe Checks")</span> <span class="Normal">case</span> HASH_OLD: <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 << 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> << <span class="Constant">"'hash_old' takes exactly one ingredient rather than '"</span> << inst<span class="Delimiter">.</span>original_string << <span class="Constant">"'</span><span class="cSpecial">\n</span><span class="Constant">"</span> << 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>!is_mu_string<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> <span class="Delimiter">{</span> raise << 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> << <span class="Constant">"'hash_old' currently only supports strings (address:array:character), but got '"</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>original_string << <span class="Constant">"'</span><span class="cSpecial">\n</span><span class="Constant">"</span> << 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 "End Primitive Recipe Implementations")</span> <span class="Normal">case</span> HASH_OLD: <span class="Delimiter">{</span> string input = read_mu_string<span class="Delimiter">(</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">));</span> <span class="Normal">size_t</span> h = <span class="Constant">0</span> <span class="Delimiter">;</span> <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">0</span><span class="Delimiter">;</span> i < SIZE<span class="Delimiter">(</span>input<span class="Delimiter">);</span> ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span> h += <span class="Normal">static_cast</span><<span class="Normal">size_t</span>><span class="Delimiter">(</span>input<span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">));</span> h += <span class="Delimiter">(</span>h<<<span class="Constant">10</span><span class="Delimiter">);</span> h ^= <span class="Delimiter">(</span>h>><span class="Constant">6</span><span class="Delimiter">);</span> h += <span class="Delimiter">(</span>h<<<span class="Constant">3</span><span class="Delimiter">);</span> h ^= <span class="Delimiter">(</span>h>><span class="Constant">11</span><span class="Delimiter">);</span> h += <span class="Delimiter">(</span>h<<<span class="Constant">15</span><span class="Delimiter">);</span> <span class="Delimiter">}</span> products<span class="Delimiter">.</span>resize<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">);</span> products<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>push_back<span class="Delimiter">(</span>h<span class="Delimiter">);</span> <span class="Identifier">break</span><span class="Delimiter">;</span> <span class="Delimiter">}</span> </pre> </body> </html> <!-- vim: set foldmethod=manual : -->