turtlestitch/libraries/list-utilities.xml

<blocks app="Snap! 4.1, http://snap.berkeley.edu" version="1"><block-definition s="append %&apos;lists&apos;" type="reporter" category="lists"><comment x="0" y="0" w="287" collapsed="false">Take any number of input lists, and create a new list containing the items of the input lists.  So&#xD;              APPEND [A B] [C D]&#xD;where the [,,,] are lists reports the list&#xD;              [A B C D]&#xD;not [[A B] [C D]].</comment><header></header><code></code><inputs><input type="%mult%l"></input></inputs><script><block s="doWarp"><script><block s="doIf"><block s="reportEquals"><block var="lists"/><block s="reportNewList"><list></list></block></block><script><block s="doReport"><block s="reportNewList"><list></list></block></block></script></block><block s="doIf"><block s="reportEquals"><block s="reportListLength"><block var="lists"/></block><l>1</l></block><script><block s="doReport"><block s="reportListItem"><l>1</l><block var="lists"/></block></block></script></block><block s="doIf"><block s="reportEquals"><block s="reportListItem"><l>1</l><block var="lists"/></block><block s="reportNewList"><list></list></block></block><script><block s="doReport"><custom-block s="append %mult%l"><block s="reportCDR"><block var="lists"/></block></custom-block></block></script></block><block s="doReport"><block s="reportCONS"><block s="reportListItem"><l>1</l><block s="reportListItem"><l>1</l><block var="lists"/></block></block><custom-block s="append %mult%l"><block s="reportCONS"><block s="reportCDR"><block s="reportListItem"><l>1</l><block var="lists"/></block></block><block s="reportCDR"><block var="lists"/></block></block></custom-block></block></block></script></block></script></block-definition><block-definition s="reverse %&apos;data&apos;" type="reporter" category="lists"><comment x="0" y="0" w="223" collapsed="false">Reports a new list containing the items of the input list, but in the opposite order.</comment><header></header><code></code><inputs><input type="%l"></input></inputs><script><block s="doDeclareVariables"><list><l>helper</l></list></block><block s="doSetVar"><l>helper</l><block s="reifyScript"><script><block s="doIf"><block s="reportEquals"><block var="input"/><block s="reportNewList"><list></list></block></block><script><block s="doReport"><block var="result"/></block></script></block><block s="doReport"><block s="evaluate"><block var="helper"/><list><block s="reportCDR"><block var="input"/></block><block s="reportCONS"><block s="reportListItem"><l>1</l><block var="input"/></block><block var="result"/></block></list></block></block></script><list><l>input</l><l>result</l></list></block></block><block s="doWarp"><script><block s="doReport"><block s="evaluate"><block var="helper"/><list><block var="data"/><block s="reportNewList"><list></list></block></list></block></block></script></block></script></block-definition><block-definition s="remove duplicates from %&apos;data&apos;" type="reporter" category="lists"><comment x="0" y="0" w="209" collapsed="false">Reports a new list whose items are the same as in the input list, except that if two or more equal items appear in the input list, only the last one is kept in the result.</comment><header></header><code></code><inputs><input type="%l"></input></inputs><script><block s="doWarp"><script><block s="doIf"><block s="reportEquals"><block var="data"/><block s="reportNewList"><list></list></block></block><script><block s="doReport"><block s="reportNewList"><list></list></block></block></script></block><block s="doIfElse"><block s="reportListContainsItem"><block s="reportCDR"><block var="data"/></block><block s="reportListItem"><l>1</l><block var="data"/></block></block><script><block s="doReport"><custom-block s="remove duplicates from %l"><block s="reportCDR"><block var="data"/></block></custom-block></block></script><script><block s="doReport"><block s="reportCONS"><block s="reportListItem"><l>1</l><block var="data"/></block><custom-block s="remove duplicates from %l"><block s="reportCDR"><block var="data"/></block></custom-block></block></block></script></block></script></block></script></block-definition><block-definition s="sort %&apos;data&apos; ordering with %&apos;function&apos;" type="reporter" category="lists"><comment x="0" y="0" w="204" collapsed="false">Reports a sorted version of the list in its first input slot, using the comparison function in the second input slot.  For a list of numbers, using &lt; as the comparison function will sort from low to high; using &gt; will sort from high to low.</comment><header></header><code></code><inputs><input type="%l"></input><input type="%predRing"></input></inputs><script><block s="doDeclareVariables"><list><l>even items</l><l>odd items</l><l>merge</l></list></block><block s="doSetVar"><l>odd items</l><block s="reifyScript"><script><block s="doIf"><block s="reportEquals"><l></l><block s="reportNewList"><list></list></block></block><script><block s="doReport"><block s="reportNewList"><list></list></block></block></script></block><block s="doReport"><block s="reportCONS"><block s="reportListItem"><l>1</l><l/></block><block s="evaluate"><block var="even items"/><list><block s="reportCDR"><l/></block></list></block></block></block></script><list></list></block></block><block s="doSetVar"><l>even items</l><block s="reifyScript"><script><block s="doIf"><block s="reportEquals"><l></l><block s="reportNewList"><list></list></block></block><script><block s="doReport"><block s="reportNewList"><list></list></block></block></script></block><block s="doReport"><block s="evaluate"><block var="odd items"/><list><block s="reportCDR"><l/></block></list></block></block></script><list></list></block></block><block s="doSetVar"><l>merge</l><block s="reifyScript"><script><block s="doIf"><block s="reportEquals"><block var="#1"/><block s="reportNewList"><list></list></block></block><script><block s="doReport"><block var="#2"/></block></script></block><block s="doIf"><block s="reportEquals"><block var="#2"/><block s="reportNewList"><list></list></block></block><script><block s="doReport"><block var="#1"/></block></script></block><block s="doIfElse"><block s="evaluate"><block var="function"/><list><block s="reportListItem"><l>1</l><block var="#1"/></block><block s="reportListItem"><l>1</l><block var="#2"/></block></list></block><script><block s="doReport"><block s="reportCONS"><block s="reportListItem"><l>1</l><block var="#1"/></block><block s="evaluate"><block var="merge"/><list><block s="reportCDR"><block var="#1"/></block><block var="#2"/></list></block></block></block></script><script><block s="doReport"><block s="reportCONS"><block s="reportListItem"><l>1</l><block var="#2"/></block><block s="evaluate"><block var="merge"/><list><block var="#1"/><block s="reportCDR"><block var="#2"/></block></list></block></block></block></script></block></script><list><l>#1</l><l>#2</l></list></block></block><block s="doIf"><block s="reportEquals"><block var="data"/><block s="reportNewList"><list></list></block></block><script><block s="doReport"><block s="reportNewList"><list></list></block></block></script></block><block s="doIf"><block s="reportEquals"><block s="reportCDR"><block var="data"/></block><block s="reportNewList"><list></list></block></block><script><block s="doReport"><block var="data"/></block></script></block><block s="doReport"><block s="evaluate"><block var="merge"/><list><custom-block s="sort %l ordering with %predRing"><block s="evaluate"><block var="odd items"/><list><block var="data"/></list></block><block var="function"/></custom-block><custom-block s="sort %l ordering with %predRing"><block s="evaluate"><block var="even items"/><list><block var="data"/></list></block><block var="function"/></custom-block></list></block></block></script></block-definition><block-definition s="assoc %&apos;key&apos; %&apos;a-list&apos;" type="reporter" category="lists"><comment x="0" y="0" w="289.3333333333333" collapsed="false">The second input is an &quot;association list,&quot; a list of two-item lists.  Each of those smaller lists has a &quot;key&quot; as its first item and a &quot;value&quot; as its second.  ASSOC reports the first key-value pair in the association list whose key matches the first input.</comment><header></header><code></code><inputs><input type="%s"></input><input type="%l"></input></inputs><script><block s="doIf"><block s="reportEquals"><block var="a-list"/><block s="reportNewList"><list></list></block></block><script><block s="doReport"><block s="reportNewList"><list></list></block></block></script></block><block s="doIf"><block s="reportEquals"><block var="key"/><block s="reportListItem"><l>1</l><block s="reportListItem"><l>1</l><block var="a-list"/></block></block></block><script><block s="doReport"><block s="reportListItem"><l>1</l><block var="a-list"/></block></block></script></block><block s="doReport"><custom-block s="assoc %s %l"><block var="key"/><block s="reportCDR"><block var="a-list"/></block></custom-block></block></script></block-definition><block-definition s="%&apos;#&apos; map %&apos;function&apos; over %&apos;lists&apos;" type="reporter" category="lists"><header></header><code></code><inputs><input type="%upvar"></input><input type="%repRing"></input><input type="%mult%l"></input></inputs><script><block s="doWarp"><script><block s="doDeclareVariables"><list><l>mapone</l><l>mapmany</l></list></block><block s="doSetVar"><l>mapone</l><block s="reifyScript"><script><block s="doIf"><custom-block s="empty? %l"><block var="data"/></custom-block><script><block s="doReport"><block s="reportNewList"><list></list></block></block></script></block><block s="doSetVar"><l>#</l><block var="count"/></block><block s="doReport"><block s="reportCONS"><block s="evaluate"><block var="function"/><list><block s="reportListItem"><l>1</l><block var="data"/></block></list></block><block s="evaluate"><block var="mapone"/><list><block s="reportCDR"><block var="data"/></block><block s="reportSum"><block var="count"/><l>1</l></block></list></block></block></block></script><list><l>data</l><l>count</l></list></block></block><block s="doSetVar"><l>mapmany</l><block s="reifyScript"><script><block s="doIf"><custom-block s="empty? %l"><block s="reportListItem"><l>1</l><block var="data lists"/></block></custom-block><script><block s="doReport"><block s="reportNewList"><list></list></block></block></script></block><block s="doSetVar"><l>#</l><block var="count"/></block><block s="doReport"><block s="reportCONS"><block s="evaluate"><block var="function"/><custom-block s="%upvar map %repRing over %mult%l"><l>#</l><block s="reifyReporter"><autolambda><block s="reportListItem"><l>1</l><l/></block></autolambda><list></list></block><list><block var="data lists"/></list></custom-block></block><block s="evaluate"><block var="mapmany"/><list><custom-block s="%upvar map %repRing over %mult%l"><l>#</l><block s="reifyReporter"><autolambda><block s="reportCDR"><l/></block></autolambda><list></list></block><list><block var="data lists"/></list></custom-block><block s="reportSum"><block var="count"/><l>1</l></block></list></block></block></block></script><list><l>data lists</l><l>count</l></list></block></block><block s="doIfElse"><custom-block s="empty? %l"><block s="reportCDR"><block var="lists"/></block></custom-block><script><block s="doReport"><block s="evaluate"><block var="mapone"/><list><block s="reportListItem"><l>1</l><block var="lists"/></block><l>1</l></list></block></block></script><script><block s="doReport"><block s="evaluate"><block var="mapmany"/><list><block var="lists"/><l>1</l></list></block></block></script></block></script></block></script></block-definition><block-definition s="empty? %&apos;data&apos;" type="predicate" category="lists"><header></header><code></code><inputs><input type="%l"></input></inputs><script><block s="doReport"><block s="reportEquals"><block var="data"/><block s="reportNewList"><list></list></block></block></block></script></block-definition><block-definition s="%&apos;#&apos; keep items such that %&apos;pred&apos; from %&apos;data&apos;" type="reporter" category="lists"><header></header><code></code><inputs><input type="%upvar"></input><input type="%predRing"></input><input type="%l"></input></inputs><script><block s="doDeclareVariables"><list><l>keep-helper</l></list></block><block s="doSetVar"><l>keep-helper</l><block s="reifyScript"><script><block s="doWarp"><script><block s="doIf"><custom-block s="empty? %l"><block var="data"/></custom-block><script><block s="doReport"><block s="reportNewList"><list></list></block></block></script></block><block s="doSetVar"><l>#</l><block var="count"/></block><block s="doIfElse"><block s="evaluate"><block var="pred"/><list><block s="reportListItem"><l>1</l><block var="data"/></block></list></block><script><block s="doReport"><block s="reportCONS"><block s="reportListItem"><l>1</l><block var="data"/></block><block s="evaluate"><block var="keep-helper"/><list><block s="reportCDR"><block var="data"/></block><block s="reportSum"><block var="count"/><l>1</l></block></list></block></block></block></script><script><block s="doReport"><block s="evaluate"><block var="keep-helper"/><list><block s="reportCDR"><block var="data"/></block><block s="reportSum"><block var="count"/><l>1</l></block></list></block></block></script></block></script></block></script><list><l>data</l><l>count</l></list></block></block><block s="doReport"><block s="evaluate"><block var="keep-helper"/><list><block var="data"/><l>1</l></list></block></block></script></block-definition><block-definition s="%&apos;#&apos; for each %&apos;item&apos; of %&apos;data&apos; %&apos;action&apos;" type="command" category="lists"><header></header><code></code><inputs><input type="%upvar"></input><input type="%upvar"></input><input type="%l"></input><input type="%cs"></input></inputs><script><block s="doSetVar"><l>#</l><l>1</l></block><block s="doUntil"><custom-block s="empty? %l"><block var="data"/></custom-block><script><block s="doSetVar"><l>item</l><block s="reportListItem"><l>1</l><block var="data"/></block></block><block s="doRun"><block var="action"/><list><block s="reportListItem"><l>1</l><block var="data"/></block></list></block><block s="doSetVar"><l>data</l><block s="reportCDR"><block var="data"/></block></block><block s="doChangeVar"><l>#</l><l>1</l></block></script></block></script></block-definition></blocks>