Updated Abstractions.
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@@ -3,15 +3,33 @@ package abstraction;
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import tester.Tester;
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class Examples {
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ILoStrings someWords = new ConsString("feldspar", new ConsString("assignment", new ConsString("curb", new LastString("carpet"))));
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ILoStrings someWords = new ConsString(
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"feldspar",
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new ConsString(
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"assignment",
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new ConsString("curb", new LastString("carpet"))
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)
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);
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boolean tests(Tester t) {
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return t.checkExpect(someWords.earliest(new OrderByShortness()), "curb")
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&& t.checkExpect(someWords.earliest(new OrderByAlpha()), "assignment")
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&& t.checkExpect(someWords.earliest(new OrderByOrder()), "feldspar")
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&& t.checkExpect(someWords.earliest(new OrderByLongness()), "assignment")
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&& t.checkExpect(someWords.earliest(new OrderByUnalpha()), "feldspar")
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&& t.checkExpect(someWords.earliest(new OrderByDisorder()), "carpet");
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return (
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t.checkExpect(someWords.earliest(new OrderByShortness()), "curb") &&
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t.checkExpect(
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someWords.earliest(new OrderByAlpha()),
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"assignment"
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) &&
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t.checkExpect(someWords.earliest(new OrderByOrder()), "feldspar") &&
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t.checkExpect(
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someWords.earliest(new OrderByLongness()),
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"assignment"
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) &&
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t.checkExpect(
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someWords.earliest(new OrderByUnalpha()),
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"feldspar"
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) &&
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t.checkExpect(someWords.earliest(new OrderByDisorder()), "carpet")
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);
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}
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}
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@@ -20,39 +38,60 @@ interface IStringsBefore {
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}
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// Negates an ordering.
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class Disorder {
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class Disorder implements IStringsBefore {
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IStringsBefore ordering;
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Disorder(IStringsBefore ordering) { this.ordering = ordering; }
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Disorder(IStringsBefore ordering) {
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this.ordering = ordering;
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}
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boolean after(String s1, String s2) {
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return ! this.ordering.before(s1, s2);
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public boolean before(String s1, String s2) {
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return !this.ordering.before(s1, s2);
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}
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}
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class OrderByShortness implements IStringsBefore { public boolean before(String s1, String s2) {
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class OrderByShortness implements IStringsBefore {
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public boolean before(String s1, String s2) {
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return s1.length() <= s2.length();
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}}
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}
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}
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class OrderByAlpha implements IStringsBefore { public boolean before(String s1, String s2) {
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class OrderByAlpha implements IStringsBefore {
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public boolean before(String s1, String s2) {
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return s1.compareTo(s2) <= 0;
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}}
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}
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}
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class OrderByOrder implements IStringsBefore { public boolean before(String s1, String s2) {
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class OrderByOrder implements IStringsBefore {
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public boolean before(String s1, String s2) {
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return true;
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}}
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}
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}
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class OrderByLongness implements IStringsBefore { public boolean before(String s1, String s2) {
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return new Disorder(new OrderByShortness()).after(s1, s2);
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}}
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class OrderByLongness implements IStringsBefore {
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class OrderByUnalpha implements IStringsBefore { public boolean before(String s1, String s2) {
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return new Disorder(new OrderByAlpha()).after(s1, s2);
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}}
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public boolean before(String s1, String s2) {
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return new Disorder(new OrderByShortness()).before(s1, s2);
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}
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}
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class OrderByDisorder implements IStringsBefore { public boolean before(String s1, String s2) {
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return new Disorder(new OrderByOrder()).after(s1, s2);
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}}
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class OrderByUnalpha implements IStringsBefore {
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public boolean before(String s1, String s2) {
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return new Disorder(new OrderByAlpha()).before(s1, s2);
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}
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}
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class OrderByDisorder implements IStringsBefore {
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public boolean before(String s1, String s2) {
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return new Disorder(new OrderByOrder()).before(s1, s2);
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}
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}
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// A non-empty list of strings.
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interface ILoStrings {
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@@ -62,14 +101,20 @@ interface ILoStrings {
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}
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abstract class ALoStrings implements ILoStrings {
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String val;
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ALoStrings(String val) { this.val = val; }
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ALoStrings(String val) {
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this.val = val;
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}
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public String val() { return this.val; }
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public String val() {
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return this.val;
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}
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}
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class ConsString extends ALoStrings {
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ILoStrings nxt;
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ConsString(String val, ILoStrings nxt) {
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@@ -78,7 +123,9 @@ class ConsString extends ALoStrings {
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}
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public String earliest(IStringsBefore ordering) {
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return ordering.before(this.val, this.nxt.val()) ? this.nxt.earliestHelper(ordering, this.val) : this.nxt.earliest(ordering);
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return ordering.before(this.val, this.nxt.val())
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? this.nxt.earliestHelper(ordering, this.val)
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: this.nxt.earliest(ordering);
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}
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public String earliestHelper(IStringsBefore ordering, String prev) {
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@@ -87,7 +134,16 @@ class ConsString extends ALoStrings {
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}
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class LastString extends ALoStrings {
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LastString(String val) { super(val); }
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public String earliest(IStringsBefore ordering) { return this.val; }
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public String earliestHelper(IStringsBefore ordering, String prev) { return prev; }
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LastString(String val) {
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super(val);
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}
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public String earliest(IStringsBefore ordering) {
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return this.val;
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}
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public String earliestHelper(IStringsBefore ordering, String prev) {
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return prev;
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}
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}
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