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></sc