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<pre id='vimCodeElement'>
<span class="Comment"># A doubly linked list permits bidirectional traversal.</span>
<span class="muData">container</span> duplex-list:_elem [
value:_elem
next:address:duplex-list:_elem
prev:address:duplex-list:_elem
]
<span class="Comment"># should I say in/contained-in:result, allow ingredients to refer to products?</span>
<span class="muRecipe">def</span> push x:_elem, in:address:duplex-list:_elem<span class="muRecipe"> -> </span>in:address:duplex-list:_elem [
<span class="Constant">local-scope</span>
<span class="Constant">load-ingredients</span>
result:address:duplex-list:_elem<span class="Special"> <- </span>new <span class="Delimiter">{</span>(duplex-list _elem): type<span class="Delimiter">}</span>
*result<span class="Special"> <- </span>merge x, in, <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="muControl">break-unless</span> in
*in<span class="Special"> <- </span>put *in, <span class="Constant">prev:offset</span>, result
<span class="Delimiter">}</span>
<span class="muControl">return</span> result <span class="Comment"># needed explicitly because we need to replace 'in' with 'result'</span>
]
<span class="muRecipe">def</span> first in:address:duplex-list:_elem<span class="muRecipe"> -> </span>result:_elem [
<span class="Constant">local-scope</span>
<span class="Constant">load-ingredients</span>
<span class="muControl">return-unless</span> in, <span class="Constant">0</span>
result<span class="Special"> <- </span>get *in, <span class="Constant">value:offset</span>
]
<span class="muRecipe">def</span> next in:address:duplex-list:_elem<span class="muRecipe"> -> </span>result:address:duplex-list:_elem/contained-in:in [
<span class="Constant">local-scope</span>
<span class="Constant">load-ingredients</span>
<span class="muControl">return-unless</span> in, <span class="Constant">0</span>
result<span class="Special"> <- </span>get *in, <span class="Constant">next:offset</span>
]
<span class="muRecipe">def</span> prev in:address:duplex-list:_elem<span class="muRecipe"> -> </span>result:address:duplex-list:_elem/contained-in:in [
<span class="Constant">local-scope</span>
<span class="Constant">load-ingredients</span>
<span class="muControl">return-unless</span> in, <span class="Constant">0</span>
result<span class="Special"> <- </span>get *in, <span class="Constant">prev:offset</span>
<span class="muControl">return</span> result
]
<span class="muScenario">scenario</span> duplex-list-handling [
run [
<span class="Constant">local-scope</span>
<span class="Comment"># reserve locations 0-9 to check for missing null check</span>
<span class="Constant">10</span>:number/<span class="Special">raw <- </span>copy <span class="Constant">34</span>
<span class="Constant">11</span>:number/<span class="Special">raw <- </span>copy <span class="Constant">35</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">3</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>push <span class="Constant">4</span>, list
list<span class="Special"> <- </span>push <span class="Constant">5</span>, list
list2:address:duplex-list:character<span class="Special"> <- </span>copy list
<span class="Constant">20</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">21</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">22</span>:character/<span class="Special">raw <- </span>first list2
<span class="Constant">30</span>:address:duplex-list:character/<span class="Special">raw <- </span>next list2
<span class="Constant">31</span>:character/<span class="Special">raw <- </span>first <span class="Constant">30</span>:address:duplex-list:character/<span class="Special">raw</span>
<span class="Constant">32</span>:address:duplex-list:character/<span class="Special">raw <- </span>next <span class="Constant">30</span>:address:duplex-list:character/<span class="Special">raw</span>
<span class="Constant">33</span>:address:duplex-list:character/<span class="Special">raw <- </span>prev <span class="Constant">30</span>:address:duplex-list:character/<span class="Special">raw</span>
list2<span class="Special"> <- </span>prev list2
<span class="Constant">40</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">41</span>:character/<span class="Special">raw <- </span>first list2
<span class="Constant">50</span>:boolean/<span class="Special">raw <- </span>equal list, list2
]
memory-should-contain [
<span class="Constant">0</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># no modifications to null pointers</span>
<span class="Constant">10</span><span class="Special"> <- </span><span class="Constant">34</span>
<span class="Constant">11</span><span class="Special"> <- </span><span class="Constant">35</span>
<span class="Constant">20</span><span class="Special"> <- </span><span class="Constant">5</span> <span class="Comment"># scanning next</span>
<span class="Constant">21</span><span class="Special"> <- </span><span class="Constant">4</span>
<span class="Constant">22</span><span class="Special"> <- </span><span class="Constant">3</span>
<span class="Constant">30</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># null</span>
<span class="Constant">31</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># first of null</span>
<span class="Constant">32</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># next of null</span>
<span class="Constant">33</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># prev of null</span>
<span class="Constant">40</span><span class="Special"> <- </span><span class="Constant">4</span> <span class="Comment"># then start scanning prev</span>
<span class="Constant">41</span><span class="Special"> <- </span><span class="Constant">5</span>
<span class="Constant">50</span><span class="Special"> <- </span><span class="Constant">1</span> <span class="Comment"># list back at start</span>
]
]
<span class="Comment"># insert 'x' after 'in'</span>
<span class="muRecipe">def</span> insert x:_elem, in:address:duplex-list:_elem<span class="muRecipe"> -> </span>in:address:duplex-list:_elem [
<span class="Constant">local-scope</span>
<span class="Constant">load-ingredients</span>
new-node:address:duplex-list:_elem<span class="Special"> <- </span>new <span class="Delimiter">{</span>(duplex-list _elem): type<span class="Delimiter">}</span>
*new-node<span class="Special"> <- </span>put *new-node, <span class="Constant">value:offset</span>, x
<span class="Comment"># save old next before changing it</span>
next-node:address:duplex-list:_elem<span class="Special"> <- </span>get *in, <span class="Constant">next:offset</span>
*in<span class="Special"> <- </span>put *in, <span class="Constant">next:offset</span>, new-node
*new-node<span class="Special"> <- </span>put *new-node, <span class="Constant">prev:offset</span>, in
*new-node<span class="Special"> <- </span>put *new-node, <span class="Constant">next:offset</span>, next-node
<span class="muControl">return-unless</span> next-node
*next-node<span class="Special"> <- </span>put *next-node, <span class="Constant">prev:offset</span>, new-node
]
<span class="muScenario">scenario</span> inserting-into-duplex-list [
run [
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">3</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>push <span class="Constant">4</span>, list
list<span class="Special"> <- </span>push <span class="Constant">5</span>, list
list2:address:duplex-list:character<span class="Special"> <- </span>next list <span class="Comment"># inside list</span>
list2<span class="Special"> <- </span>insert <span class="Constant">6</span>, list2
<span class="Comment"># check structure like before</span>
list2<span class="Special"> <- </span>copy list
<span class="Constant">10</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">11</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">12</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">13</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">20</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">21</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">22</span>:character/<span class="Special">raw <- </span>first list2
<span class="Constant">30</span>:boolean/<span class="Special">raw <- </span>equal list, list2
]
memory-should-contain [
<span class="Constant">10</span><span class="Special"> <- </span><span class="Constant">5</span> <span class="Comment"># scanning next</span>
<span class="Constant">11</span><span class="Special"> <- </span><span class="Constant">4</span>
<span class="Constant">12</span><span class="Special"> <- </span><span class="Constant">6</span> <span class="Comment"># inserted element</span>
<span class="Constant">13</span><span class="Special"> <- </span><span class="Constant">3</span>
<span class="Constant">20</span><span class="Special"> <- </span><span class="Constant">6</span> <span class="Comment"># then prev</span>
<span class="Constant">21</span><span class="Special"> <- </span><span class="Constant">4</span>
<span class="Constant">22</span><span class="Special"> <- </span><span class="Constant">5</span>
<span class="Constant">30</span><span class="Special"> <- </span><span class="Constant">1</span> <span class="Comment"># list back at start</span>
]
]
<span class="muScenario">scenario</span> inserting-at-end-of-duplex-list [
run [
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">3</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>push <span class="Constant">4</span>, list
list<span class="Special"> <- </span>push <span class="Constant">5</span>, list
list2:address:duplex-list:character<span class="Special"> <- </span>next list <span class="Comment"># inside list</span>
list2<span class="Special"> <- </span>next list2 <span class="Comment"># now at end of list</span>
list2<span class="Special"> <- </span>insert <span class="Constant">6</span>, list2
<span class="Comment"># check structure like before</span>
list2<span class="Special"> <- </span>copy list
<span class="Constant">10</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">11</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">12</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">13</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">20</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">21</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">22</span>:character/<span class="Special">raw <- </span>first list2
<span class="Constant">30</span>:boolean/<span class="Special">raw <- </span>equal list, list2
]
memory-should-contain [
<span class="Constant">10</span><span class="Special"> <- </span><span class="Constant">5</span> <span class="Comment"># scanning next</span>
<span class="Constant">11</span><span class="Special"> <- </span><span class="Constant">4</span>
<span class="Constant">12</span><span class="Special"> <- </span><span class="Constant">3</span>
<span class="Constant">13</span><span class="Special"> <- </span><span class="Constant">6</span> <span class="Comment"># inserted element</span>
<span class="Constant">20</span><span class="Special"> <- </span><span class="Constant">3</span> <span class="Comment"># then prev</span>
<span class="Constant">21</span><span class="Special"> <- </span><span class="Constant">4</span>
<span class="Constant">22</span><span class="Special"> <- </span><span class="Constant">5</span>
<span class="Constant">30</span><span class="Special"> <- </span><span class="Constant">1</span> <span class="Comment"># list back at start</span>
]
]
<span class="muScenario">scenario</span> inserting-after-start-of-duplex-list [
run [
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">3</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>push <span class="Constant">4</span>, list
list<span class="Special"> <- </span>push <span class="Constant">5</span>, list
list<span class="Special"> <- </span>insert <span class="Constant">6</span>, list
<span class="Comment"># check structure like before</span>
list2:address:duplex-list:character<span class="Special"> <- </span>copy list
<span class="Constant">10</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">11</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">12</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">13</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">20</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">21</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">22</span>:character/<span class="Special">raw <- </span>first list2
<span class="Constant">30</span>:boolean/<span class="Special">raw <- </span>equal list, list2
]
memory-should-contain [
<span class="Constant">10</span><span class="Special"> <- </span><span class="Constant">5</span> <span class="Comment"># scanning next</span>
<span class="Constant">11</span><span class="Special"> <- </span><span class="Constant">6</span> <span class="Comment"># inserted element</span>
<span class="Constant">12</span><span class="Special"> <- </span><span class="Constant">4</span>
<span class="Constant">13</span><span class="Special"> <- </span><span class="Constant">3</span>
<span class="Constant">20</span><span class="Special"> <- </span><span class="Constant">4</span> <span class="Comment"># then prev</span>
<span class="Constant">21</span><span class="Special"> <- </span><span class="Constant">6</span>
<span class="Constant">22</span><span class="Special"> <- </span><span class="Constant">5</span>
<span class="Constant">30</span><span class="Special"> <- </span><span class="Constant">1</span> <span class="Comment"># list back at start</span>
]
]
<span class="Comment"># remove 'x' from its surrounding list 'in'</span>
<span class="Comment">#</span>
<span class="Comment"># Returns null if and only if list is empty. Beware: in that case any other</span>
<span class="Comment"># pointers to the head are now invalid.</span>
<span class="muRecipe">def</span> remove x:address:duplex-list:_elem/contained-in:in, in:address:duplex-list:_elem<span class="muRecipe"> -> </span>in:address:duplex-list:_elem [
<span class="Constant">local-scope</span>
<span class="Constant">load-ingredients</span>
<span class="Comment"># if 'x' is null, return</span>
<span class="muControl">return-unless</span> x
next-node:address:duplex-list:_elem<span class="Special"> <- </span>get *x, <span class="Constant">next:offset</span>
prev-node:address:duplex-list:_elem<span class="Special"> <- </span>get *x, <span class="Constant">prev:offset</span>
<span class="Comment"># null x's pointers</span>
*x<span class="Special"> <- </span>put *x, <span class="Constant">next:offset</span>, <span class="Constant">0</span>
*x<span class="Special"> <- </span>put *x, <span class="Constant">prev:offset</span>, <span class="Constant">0</span>
<span class="Comment"># if next-node is not null, set its prev pointer</span>
<span class="Delimiter">{</span>
<span class="muControl">break-unless</span> next-node
*next-node<span class="Special"> <- </span>put *next-node, <span class="Constant">prev:offset</span>, prev-node
<span class="Delimiter">}</span>
<span class="Comment"># if prev-node is not null, set its next pointer and return</span>
<span class="Delimiter">{</span>
<span class="muControl">break-unless</span> prev-node
*prev-node<span class="Special"> <- </span>put *prev-node, <span class="Constant">next:offset</span>, next-node
<span class="muControl">return</span>
<span class="Delimiter">}</span>
<span class="Comment"># if prev-node is null, then we removed the head node at 'in'</span>
<span class="Comment"># return the new head rather than the old 'in'</span>
<span class="muControl">return</span> next-node
]
<span class="muScenario">scenario</span> removing-from-duplex-list [
run [
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">3</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>push <span class="Constant">4</span>, list
list<span class="Special"> <- </span>push <span class="Constant">5</span>, list
list2:address:duplex-list:character<span class="Special"> <- </span>next list <span class="Comment"># second element</span>
list<span class="Special"> <- </span>remove list2, list
<span class="Constant">10</span>:boolean/<span class="Special">raw <- </span>equal list2, <span class="Constant">0</span>
<span class="Comment"># check structure like before</span>
list2<span class="Special"> <- </span>copy list
<span class="Constant">11</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">12</span>:character/<span class="Special">raw <- </span>first list2
<span class="Constant">20</span>:address:duplex-list:character/<span class="Special">raw <- </span>next list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">30</span>:character/<span class="Special">raw <- </span>first list2
<span class="Constant">40</span>:boolean/<span class="Special">raw <- </span>equal list, list2
]
memory-should-contain [
<span class="Constant">10</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># remove returned non-null</span>
<span class="Constant">11</span><span class="Special"> <- </span><span class="Constant">5</span> <span class="Comment"># scanning next, skipping deleted element</span>
<span class="Constant">12</span><span class="Special"> <- </span><span class="Constant">3</span>
<span class="Constant">20</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># no more elements</span>
<span class="Constant">30</span><span class="Special"> <- </span><span class="Constant">5</span> <span class="Comment"># prev of final element</span>
<span class="Constant">40</span><span class="Special"> <- </span><span class="Constant">1</span> <span class="Comment"># list back at start</span>
]
]
<span class="muScenario">scenario</span> removing-from-start-of-duplex-list [
run [
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">3</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>push <span class="Constant">4</span>, list
list<span class="Special"> <- </span>push <span class="Constant">5</span>, list
list<span class="Special"> <- </span>remove list, list
<span class="Comment"># check structure like before</span>
list2:address:duplex-list:character<span class="Special"> <- </span>copy list
<span class="Constant">10</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">11</span>:character/<span class="Special">raw <- </span>first list2
<span class="Constant">20</span>:address:duplex-list:character/<span class="Special">raw <- </span>next list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">30</span>:character/<span class="Special">raw <- </span>first list2
<span class="Constant">40</span>:boolean/<span class="Special">raw <- </span>equal list, list2
]
memory-should-contain [
<span class="Constant">10</span><span class="Special"> <- </span><span class="Constant">4</span> <span class="Comment"># scanning next, skipping deleted element</span>
<span class="Constant">11</span><span class="Special"> <- </span><span class="Constant">3</span>
<span class="Constant">20</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># no more elements</span>
<span class="Constant">30</span><span class="Special"> <- </span><span class="Constant">4</span> <span class="Comment"># prev of final element</span>
<span class="Constant">40</span><span class="Special"> <- </span><span class="Constant">1</span> <span class="Comment"># list back at start</span>
]
]
<span class="muScenario">scenario</span> removing-from-end-of-duplex-list [
run [
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">3</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>push <span class="Constant">4</span>, list
list<span class="Special"> <- </span>push <span class="Constant">5</span>, list
<span class="Comment"># delete last element</span>
list2:address:duplex-list:character<span class="Special"> <- </span>next list
list2<span class="Special"> <- </span>next list2
list<span class="Special"> <- </span>remove list2, list
<span class="Constant">10</span>:boolean/<span class="Special">raw <- </span>equal list2, <span class="Constant">0</span>
<span class="Comment"># check structure like before</span>
list2<span class="Special"> <- </span>copy list
<span class="Constant">11</span>:character/<span class="Special">raw <- </span>first list2
list2<span class="Special"> <- </span>next list2
<span class="Constant">12</span>:character/<span class="Special">raw <- </span>first list2
<span class="Constant">20</span>:address:duplex-list:character/<span class="Special">raw <- </span>next list2
list2<span class="Special"> <- </span>prev list2
<span class="Constant">30</span>:character/<span class="Special">raw <- </span>first list2
<span class="Constant">40</span>:boolean/<span class="Special">raw <- </span>equal list, list2
]
memory-should-contain [
<span class="Constant">10</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># remove returned non-null</span>
<span class="Constant">11</span><span class="Special"> <- </span><span class="Constant">5</span> <span class="Comment"># scanning next, skipping deleted element</span>
<span class="Constant">12</span><span class="Special"> <- </span><span class="Constant">4</span>
<span class="Constant">20</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># no more elements</span>
<span class="Constant">30</span><span class="Special"> <- </span><span class="Constant">5</span> <span class="Comment"># prev of final element</span>
<span class="Constant">40</span><span class="Special"> <- </span><span class="Constant">1</span> <span class="Comment"># list back at start</span>
]
]
<span class="muScenario">scenario</span> removing-from-singleton-duplex-list [
run [
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">3</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>remove list, list
<span class="Constant">1</span>:number/<span class="Special">raw <- </span>copy list
]
memory-should-contain [
<span class="Constant">1</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># back to an empty list</span>
]
]
<span class="Comment"># remove values between 'start' and 'end' (both exclusive).</span>
<span class="Comment"># also clear pointers back out from start/end for hygiene.</span>
<span class="Comment"># set end to 0 to delete everything past start.</span>
<span class="Comment"># can't set start to 0 to delete everything before end, because there's no</span>
<span class="Comment"># clean way to return the new head pointer.</span>
<span class="muRecipe">def</span> remove-between start:address:duplex-list:_elem, end:address:duplex-list:_elem/contained-in:start<span class="muRecipe"> -> </span>start:address:duplex-list:_elem [
<span class="Constant">local-scope</span>
<span class="Constant">load-ingredients</span>
next:address:duplex-list:_elem<span class="Special"> <- </span>get *start, <span class="Constant">next:offset</span>
nothing-to-delete?:boolean<span class="Special"> <- </span>equal next, end
<span class="muControl">return-if</span> nothing-to-delete?
assert next, <span class="Constant">[malformed duplex list]</span>
<span class="Comment"># start->next->prev = 0</span>
<span class="Comment"># start->next = end</span>
*next<span class="Special"> <- </span>put *next, <span class="Constant">prev:offset</span>, <span class="Constant">0</span>
*start<span class="Special"> <- </span>put *start, <span class="Constant">next:offset</span>, end
<span class="muControl">return-unless</span> end
<span class="Comment"># end->prev->next = 0</span>
<span class="Comment"># end->prev = start</span>
prev:address:duplex-list:_elem<span class="Special"> <- </span>get *end, <span class="Constant">prev:offset</span>
assert prev, <span class="Constant">[malformed duplex list - 2]</span>
*prev<span class="Special"> <- </span>put *prev, <span class="Constant">next:offset</span>, <span class="Constant">0</span>
*end<span class="Special"> <- </span>put *end, <span class="Constant">prev:offset</span>, start
]
<span class="muScenario">scenario</span> remove-range [
<span class="Comment"># construct a duplex list with six elements [13, 14, 15, 16, 17, 18]</span>
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">18</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>push <span class="Constant">17</span>, list
list<span class="Special"> <- </span>push <span class="Constant">16</span>, list
list<span class="Special"> <- </span>push <span class="Constant">15</span>, list
list<span class="Special"> <- </span>push <span class="Constant">14</span>, list
list<span class="Special"> <- </span>push <span class="Constant">13</span>, list
<span class="Constant">1</span>:address:duplex-list:character/<span class="Special">raw <- </span>copy list <span class="Comment"># save list</span>
run [
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>copy <span class="Constant">1</span>:address:duplex-list:character/<span class="Special">raw</span> <span class="Comment"># restore list</span>
<span class="Comment"># delete 16 onwards</span>
<span class="Comment"># first pointer: to the third element</span>
list2:address:duplex-list:character<span class="Special"> <- </span>next list
list2<span class="Special"> <- </span>next list2
list2<span class="Special"> <- </span>remove-between list2, <span class="Constant">0</span>
<span class="Comment"># now check the list</span>
<span class="Constant">10</span>:character/<span class="Special">raw <- </span>get *list, <span class="Constant">value:offset</span>
list<span class="Special"> <- </span>next list
<span class="Constant">11</span>:character/<span class="Special">raw <- </span>get *list, <span class="Constant">value:offset</span>
list<span class="Special"> <- </span>next list
<span class="Constant">12</span>:character/<span class="Special">raw <- </span>get *list, <span class="Constant">value:offset</span>
<span class="Constant">20</span>:address:duplex-list:character/<span class="Special">raw <- </span>next list
]
memory-should-contain [
<span class="Constant">10</span><span class="Special"> <- </span><span class="Constant">13</span>
<span class="Constant">11</span><span class="Special"> <- </span><span class="Constant">14</span>
<span class="Constant">12</span><span class="Special"> <- </span><span class="Constant">15</span>
<span class="Constant">20</span><span class="Special"> <- </span><span class="Constant">0</span>
]
]
<span class="muScenario">scenario</span> remove-range-to-final [
<span class="Constant">local-scope</span>
<span class="Comment"># construct a duplex list with six elements [13, 14, 15, 16, 17, 18]</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">18</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>push <span class="Constant">17</span>, list
list<span class="Special"> <- </span>push <span class="Constant">16</span>, list
list<span class="Special"> <- </span>push <span class="Constant">15</span>, list
list<span class="Special"> <- </span>push <span class="Constant">14</span>, list
list<span class="Special"> <- </span>push <span class="Constant">13</span>, list
<span class="Constant">1</span>:address:duplex-list:character/<span class="Special">raw <- </span>copy list <span class="Comment"># save list</span>
run [
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>copy <span class="Constant">1</span>:address:duplex-list:character/<span class="Special">raw</span> <span class="Comment"># restore list</span>
<span class="Comment"># delete 15, 16 and 17</span>
<span class="Comment"># start pointer: to the second element</span>
list2:address:duplex-list:character<span class="Special"> <- </span>next list
<span class="Comment"># end pointer: to the last (sixth) element</span>
end:address:duplex-list:character<span class="Special"> <- </span>next list2
end<span class="Special"> <- </span>next end
end<span class="Special"> <- </span>next end
end<span class="Special"> <- </span>next end
remove-between list2, end
<span class="Comment"># now check the list</span>
<span class="Constant">10</span>:character/<span class="Special">raw <- </span>get *list, <span class="Constant">value:offset</span>
list<span class="Special"> <- </span>next list
<span class="Constant">11</span>:character/<span class="Special">raw <- </span>get *list, <span class="Constant">value:offset</span>
list<span class="Special"> <- </span>next list
<span class="Constant">12</span>:character/<span class="Special">raw <- </span>get *list, <span class="Constant">value:offset</span>
<span class="Constant">20</span>:address:duplex-list:character/<span class="Special">raw <- </span>next list
]
memory-should-contain [
<span class="Constant">10</span><span class="Special"> <- </span><span class="Constant">13</span>
<span class="Constant">11</span><span class="Special"> <- </span><span class="Constant">14</span>
<span class="Constant">12</span><span class="Special"> <- </span><span class="Constant">18</span>
<span class="Constant">20</span><span class="Special"> <- </span><span class="Constant">0</span> <span class="Comment"># no more elements</span>
]
]
<span class="muScenario">scenario</span> remove-range-empty [
<span class="Constant">local-scope</span>
<span class="Comment"># construct a duplex list with three elements [13, 14, 15]</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">15</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>push <span class="Constant">14</span>, list
list<span class="Special"> <- </span>push <span class="Constant">13</span>, list
<span class="Constant">1</span>:address:duplex-list:character/<span class="Special">raw <- </span>copy list <span class="Comment"># save list</span>
run [
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>copy <span class="Constant">1</span>:address:duplex-list:character/<span class="Special">raw</span> <span class="Comment"># restore list</span>
<span class="Comment"># delete between first and second element (i.e. nothing)</span>
list2:address:duplex-list:character<span class="Special"> <- </span>next list
remove-between list, list2
<span class="Comment"># now check the list</span>
<span class="Constant">10</span>:character/<span class="Special">raw <- </span>get *list, <span class="Constant">value:offset</span>
list<span class="Special"> <- </span>next list
<span class="Constant">11</span>:character/<span class="Special">raw <- </span>get *list, <span class="Constant">value:offset</span>
list<span class="Special"> <- </span>next list
<span class="Constant">12</span>:character/<span class="Special">raw <- </span>get *list, <span class="Constant">value:offset</span>
<span class="Constant">20</span>:address:duplex-list:character/<span class="Special">raw <- </span>next list
]
<span class="Comment"># no change</span>
memory-should-contain [
<span class="Constant">10</span><span class="Special"> <- </span><span class="Constant">13</span>
<span class="Constant">11</span><span class="Special"> <- </span><span class="Constant">14</span>
<span class="Constant">12</span><span class="Special"> <- </span><span class="Constant">15</span>
<span class="Constant">20</span><span class="Special"> <- </span><span class="Constant">0</span>
]
]
<span class="muScenario">scenario</span> remove-range-to-end [
<span class="Constant">local-scope</span>
<span class="Comment"># construct a duplex list with six elements [13, 14, 15, 16, 17, 18]</span>
list:address:duplex-list:character<span class="Special"> <- </span>push <span class="Constant">18</span>, <span class="Constant">0</span>
list<span class="Special"> <- </span>push <span class="Constant">17</span>, list
list<span class="Special"> <- </span>push <span class="Constant">16</span>, list
list<span class="Special"> <- </span>push <span class="Constant">15</span>, list
list<span class="Special"> <- </span>push <span class="Constant">14</span>, list
list<span class="Special"> <- </span>push <span class="Constant">13</span>, list
<span class="Constant">1</span>:address:duplex-list:character/<span class="Special">raw <- </span>copy list <span class="Comment"># save list</span>
run [
<span class="Constant">local-scope</span>
list:address:duplex-list:character<span class="Special"> <- </span>copy <span class="Constant">1</span>:address:duplex-list:character/<span class="Special">raw</span> <span class="Comment"># restore list</span>
<span class="Comment"># remove the third element and beyond</span>
list2:address:duplex-list:character<span class="Special"> <- </span>next list
remove-between list2, <span class="Constant">0</span>
<span class="Comment"># now check the list</span>
<span class="Constant">10</span>:character/<span class="Special">raw <- </span>get *list, <span class="Constant">value:offset</span>
list<span class="Special"> <- </span>next list
<span class="Constant">11</span>:character/<span class="Special">raw <- </span>get *list, <span class="Constant">value:offset</span>
<span class="Constant">20</span>:address:duplex-list:character/<span class="Special">raw <- </span>next list
]
memory-should-contain [
<span class="Constant">10</span><span class="Special"> <- </span><span class="Constant">13</span>
<span class="Constant">11</span><span class="Special"> <- </span><span class="Constant">14</span>
<span class="Constant">20</span><span class="Special"> <- </span><span class="Constant">0</span>
]
]
<span class="Comment"># insert list beginning at 'new' after 'in'</span>
<span class="muRecipe">def</span> insert-range in:address:duplex-list:_elem, start:address:duplex-list:_elem/contained-in:in<span class="muRecipe"> -> </span>in:address:duplex-list:_elem [
<span class="Constant">local-scope</span>
<span class="Constant">load-ingredients</span>
<span class="muControl">return-unless</span> in
<span class="muControl">return-unless</span> start
end:address:duplex-list:_elem<span class="Special"> <- </span>copy start
<span class="Delimiter">{</span>
next:address:duplex-list:_elem<span class="Special"> <- </span>next end/insert-range
<span class="muControl">break-unless</span> next
end<span class="Special"> <- </span>copy next
<span class="muControl">loop</span>
<span class="Delimiter">}</span>
next:address:duplex-list:_elem<span class="Special"> <- </span>next in
*end<span class="Special"> <- </span>put *end, <span class="Constant">next:offset</span>, next
<span class="Delimiter">{</span>
<span class="muControl">break-unless</span> next
*next<span class="Special"> <- </span>put *next, <span class="Constant">prev:offset</span>, end
<span class="Delimiter">}</span>
*in<span class="Special"> <- </span>put *in, <span class="Constant">next:offset</span>, start
*start<span class="Special"> <- </span>put *start, <span class="Constant">prev:offset</span>, in
]
<span class="muRecipe">def</span> append in:address:duplex-list:_elem, new:address:duplex-list:_elem/contained-in:in<span class="muRecipe"> -> </span>in:address:duplex-list:_elem [
<span class="Constant">local-scope</span>
<span class="Constant">load-ingredients</span>
last:address:duplex-list:_elem<span class="Special"> <- </span>last in
*last<span class="Special"> <- </span>put *last, <span class="Constant">next:offset</span>, new
<span class="muControl">return-unless</span> new
*new<span class="Special"> <- </span>put *new, <span class="Constant">prev:offset</span>, last
]
<span class="muRecipe">def</span> last in:address:duplex-list:_elem<span class="muRecipe"> -> </span>result:address:duplex-list:_elem [
<span class="Constant">local-scope</span>
<span class="Constant">load-ingredients</span>
result<span class="Special"> <- </span>copy in
<span class="Delimiter">{</span>
next:address:duplex-list:_elem<span class="Special"> <- </span>next result
<span class="muControl">break-unless</span> next
result<span class="Special"> <- </span>copy next
<span class="muControl">loop</span>
<span class="Delimiter">}</span>
]
<span class="Comment"># helper for debugging</span>
<span class="muRecipe">def</span> dump-from x:address:duplex-list:_elem [
<span class="Constant">local-scope</span>
<span class="Constant">load-ingredients</span>
$print x, <span class="Constant">[: ]</span>
<span class="Delimiter">{</span>
<span class="muControl">break-unless</span> x
c:_elem<span class="Special"> <- </span>get *x, <span class="Constant">value:offset</span>
$print c, <span class="Constant">[ ]</span>
x<span class="Special"> <- </span>next x
<span class="Delimiter">{</span>
is-newline?:boolean<span class="Special"> <- </span>equal c, <span class="Constant">10/newline</span>
<span class="muControl">break-unless</span> is-newline?
$print <span class="Constant">10/newline</span>
$print x, <span class="Constant">[: ]</span>
<span class="Delimiter">}</span>
<span class="muControl">loop</span>
<span class="Delimiter">}</span>
$print <span class="Constant">10/newline</span>, <span class="Constant">[---]</span>, <span class="Constant">10/newline</span>
]
</pre>
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