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<HTML><HEAD><TITLE>6.1 Records in General</TITLE><LINK href="ozdoc.css" rel="stylesheet" type="text/css"></HEAD><BODY><TABLE align="center" border="0" cellpadding="6" cellspacing="6" class="nav"><TR bgcolor="#DDDDDD"><TD><A href="node8.html">- Up -</A></TD><TD><A href="tuple.html#section.records.tuples">Next >></A></TD></TR></TABLE><DIV id="section.records.records"><H2><A name="section.records.records">6.1 Records in General</A></H2><P> The module <A name="label176"></A><SPAN class="index"><CODE>Record</CODE></SPAN> contains procedures operating on records. </P><P> Procedures that iterate over the subtrees of a record operate in ascending order as specified for <CODE>Arity</CODE>. </P><DL><DT><A name="label177"></A><SPAN class="index"><CODE><SPAN class="keyword">.</SPAN></CODE></SPAN> <A name="label178"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Value<SPAN class="keyword">.</SPAN><SPAN class="string">'.'</SPAN> </CODE><CODE>+<I>RC</I></CODE><CODE> </CODE><CODE>+<I>LI</I></CODE><CODE> </CODE><CODE><I>X</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>returns the field <CODE><I>X</I></CODE> of <CODE><I>RC</I></CODE> at feature <CODE><I>LI</I></CODE>. </P></DD><DT><A name="label179"></A><SPAN class="index"><CODE>HasFeature</CODE></SPAN> <A name="label180"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Value<SPAN class="keyword">.</SPAN>hasFeature </CODE><CODE>+<I>RC</I></CODE><CODE> </CODE><CODE>+<I>LI</I></CODE><CODE> </CODE><CODE>?<I>B</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>tests whether <CODE><I>RC</I></CODE> has feature <CODE><I>LI</I></CODE>. </P></DD><DT><A name="label181"></A><SPAN class="index"><CODE>CondSelect</CODE></SPAN> <A name="label182"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Value<SPAN class="keyword">.</SPAN>condSelect </CODE><CODE>+<I>RC</I></CODE><CODE> </CODE><CODE>+<I>LI</I></CODE><CODE> </CODE><CODE><I>X</I></CODE><CODE> </CODE><CODE><I>Y</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>returns the field of <CODE><I>RC</I></CODE> at feature <CODE><I>LI</I></CODE>, if <CODE><I>RC</I></CODE> has feature <CODE><I>LI</I></CODE>. Otherwise, return <CODE><I>X</I></CODE>. </P></DD><DT><A name="label183"></A><SPAN class="index"><CODE>IsRecord</CODE></SPAN> <A name="label185"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>is </CODE><CODE>+<I>X</I></CODE><CODE> </CODE><CODE>?<I>B</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>tests whether <CODE><I>X</I></CODE> is a record. </P></DD><DT><A name="label186"></A><SPAN class="index"><CODE>MakeRecord</CODE></SPAN> <A name="label188"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>make </CODE><CODE>+<I>L</I></CODE><CODE> </CODE><CODE>+<I>LIs</I></CODE><CODE> </CODE><CODE>?<I>R</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>returns a new record with label <CODE><I>L</I></CODE>, features <CODE><I>LIs</I></CODE>, and fresh variables at every field. All elements of <CODE><I>LIs</I></CODE> must be pairwise distinct, else an error exception is raised. </P><P> For example, <CODE>{MakeRecord L A R}</CODE> waits until <CODE>L</CODE> is bound to a literal, say <CODE>b</CODE>, and <CODE>A</CODE> is bound to a list of literals and integers, say <CODE>[c d 1]</CODE>, and then binds <CODE>R</CODE> to <CODE>b(_ c: _ d: _)</CODE>. </P></DD><DT><A name="label189"></A><SPAN class="index"><CODE>clone</CODE></SPAN> <A name="label191"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>clone </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>returns a record <CODE><I>R2</I></CODE> with the same label and features as <CODE><I>R1</I></CODE> and fresh variables at every field. </P></DD><DT><A name="label192"></A><SPAN class="index"><CODE>Label</CODE></SPAN> <A name="label193"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>label </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>?<I>L</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>returns the label of <CODE><I>R</I></CODE> in <CODE><I>L</I></CODE>. </P></DD><DT><A name="label194"></A><SPAN class="index"><CODE>Width</CODE></SPAN> <A name="label195"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>width </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>?<I>I</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>returns the width of <CODE><I>R</I></CODE> in <CODE><I>I</I></CODE>. </P></DD><DT><A name="label196"></A><SPAN class="index"><CODE>Arity</CODE></SPAN> <A name="label197"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>arity </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>?<I>LIs</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>returns the arity <CODE><I>LIs</I></CODE> of <CODE><I>R</I></CODE>. The arity of <CODE><I>R</I></CODE> is the list of its features, beginning with all integer features in ascending order, followed by the literal features. The atomic literals occur in ascending order interspersed with names. </P><P> For example, <CODE>{Arity a(nil 7 c: 1 b: c)}</CODE> yields <CODE>[1 2 b c]</CODE> as output. </P></DD><DT><A name="label198"></A><SPAN class="index"><CODE>Adjoin</CODE></SPAN> <A name="label199"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>adjoin </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>R2</I></CODE><CODE> </CODE><CODE>?<I>R3</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>returns the result of adjoining <CODE><I>R2</I></CODE> to <CODE><I>R1</I></CODE>. Note that features and label in R2 take precedence over R1. </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{Adjoin a(a b c: 1) b(4 b: 3 c: 2)}</CODE></BLOCKQUOTE><P> yields the record <CODE>b(4 b b: 3 c: 2)</CODE> as output. </P></DD><DT><A name="label200"></A><SPAN class="index"><CODE>AdjoinAt</CODE></SPAN> <A name="label201"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>adjoinAt </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>LI</I></CODE><CODE> </CODE><CODE><I>X</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>binds <CODE><I>R2</I></CODE> to the result of adjoining the field <CODE><I>X</I></CODE> to <CODE><I>R1</I></CODE> at feature <CODE><I>LI</I></CODE>. </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{AdjoinAt a(a c: 1) 2 b}</CODE></BLOCKQUOTE><P> yields <CODE>a(a b c: 1)</CODE> as output, whereas </P><BLOCKQUOTE class="code"><CODE>{AdjoinAt a(a c: 1) c b}</CODE></BLOCKQUOTE><P> yields <CODE>a(a c: b)</CODE> as output. </P></DD><DT><A name="label202"></A><SPAN class="index"><CODE>AdjoinList</CODE></SPAN> <A name="label203"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>adjoinList </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>Ts</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>binds <CODE><I>R2</I></CODE> to the result of adjoining to <CODE><I>R1</I></CODE> all entries of <CODE><I>Ts</I></CODE>, a finite list of pairs whose first components are literals or integers, representing features. Features further to the right overwrite features further to the left. </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{AdjoinList a(b:1 c:2) [d<SPAN class="keyword">#</SPAN>3 c<SPAN class="keyword">#</SPAN>4 d<SPAN class="keyword">#</SPAN>5]}</CODE></BLOCKQUOTE><P> yields <CODE>a(b: 1 c: 4 d: 5)</CODE> as output. </P></DD><DT><CODE>subtract</CODE> <A name="label205"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>subtract </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>LI</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>If <CODE><I>R1</I></CODE> has feature <CODE><I>LI</I></CODE>, returns record <CODE><I>R1</I></CODE> with feature <CODE><I>LI</I></CODE> removed. Otherwise, returns <CODE><I>R1</I></CODE>. </P></DD><DT><CODE>subtractList</CODE> <A name="label207"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>subtractList </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>LIs</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>Returns record <CODE><I>R1</I></CODE> with all features in <CODE><I>LIs</I></CODE> removed. </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>subtractList f(jim: 1 jack: 2 jesse: 4) [jesse jim]}</CODE></BLOCKQUOTE><P> returns the record <CODE>f(jack: 2)</CODE>. </P></DD><DT><CODE>zip</CODE> <A name="label209"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>zip </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>R2</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R3</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>Given two records <CODE><I>R1</I></CODE> and <CODE><I>R2</I></CODE> and a ternary procedure <CODE><I>P</I></CODE>, <CODE><I>R3</I></CODE> is bound to a record with the same label as <CODE><I>R1</I></CODE> and those features which are common to <CODE><I>R1</I></CODE> and <CODE><I>R2</I></CODE>. Features appearing only in one of the records are silently dropped. Each fields <CODE><I>X</I></CODE> of <CODE><I>R3</I></CODE> is computed by applying <CODE>{</CODE><CODE><I>P</I></CODE><CODE> </CODE><CODE><I>R1</I></CODE><CODE><SPAN class="keyword">.</SPAN></CODE><CODE><I>X</I></CODE><CODE> </CODE><CODE><I>R2</I></CODE><CODE><SPAN class="keyword">.</SPAN></CODE><CODE><I>X</I></CODE><CODE> </CODE><CODE><I>R3</I></CODE><CODE><SPAN class="keyword">.</SPAN></CODE><CODE><I>X</I></CODE><CODE>}</CODE>. </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>zip<BR> f(jim: 1 jack: 2 jesse: 4)<BR> g(jim: a jack: b joe: c)<BR> <SPAN class="keyword">fun</SPAN><SPAN class="variablename"> </SPAN>{<SPAN class="functionname">$</SPAN> X Y} X<SPAN class="keyword">#</SPAN>Y <SPAN class="keyword">end</SPAN>}</CODE></BLOCKQUOTE><P> yields as output the record <CODE>f(jim: 1<SPAN class="keyword">#</SPAN>a jack: 2<SPAN class="keyword">#</SPAN>b)</CODE>. </P></DD><DT><CODE>toList</CODE> <A name="label211"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>toList </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>?<I>Xs</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>binds <CODE><I>Xs</I></CODE> to list of all fields of <CODE><I>R</I></CODE> in the order as given by <CODE>Arity</CODE> (which see). </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>toList f(a a: 2 b: 3)}</CODE></BLOCKQUOTE><P> yields <CODE>[a 2 3]</CODE> as output. </P></DD><DT><CODE>toListInd</CODE> <A name="label213"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>toListInd </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>?<I>Ts</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>binds <CODE><I>Ts</I></CODE> to the property list that contains the feature-field pairs of <CODE><I>R</I></CODE> in the order as given by <CODE>Arity</CODE> (which see). </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>toListInd f(a a: 2 b: 3)}</CODE></BLOCKQUOTE><P> yields <CODE>[1<SPAN class="keyword">#</SPAN>a a<SPAN class="keyword">#</SPAN>2 b<SPAN class="keyword">#</SPAN>3]</CODE> as output. </P></DD><DT><CODE>toDictionary</CODE> <A name="label215"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>toDictionary </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>?<I>Dictionary</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>returns a dictionary <CODE><I>Dictionary</I></CODE> whose keys and their entries correspond to the features and their fields of <CODE><I>R</I></CODE>. </P></DD></DL><P> </P><P> All of the following procedures are provided in two versions. The so-called <EM>index</EM> version passes to the procedures an additional index as first actual argument. The index is an integer or a literal giving the feature of the field currently processed. </P><DL><DT><CODE>map</CODE> <A name="label217"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>map </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>returns a record with same label and arity as <CODE><I>R1</I></CODE>, whose fields are computed by applying the binary procedure <CODE><I>P</I></CODE> to all fields of <CODE><I>R1</I></CODE>. </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>map a(12 b: 13 c: 1) IntToFloat}</CODE></BLOCKQUOTE><P> yields the record <CODE>a(12<SPAN class="keyword">.</SPAN>0 b: 13<SPAN class="keyword">.</SPAN>0 c: 1<SPAN class="keyword">.</SPAN>0)</CODE> as output. </P></DD><DT><CODE>mapInd</CODE> <A name="label219"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>mapInd </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>is similar to <CODE>Record<SPAN class="keyword">.</SPAN>map</CODE>, but the ternary procedure <CODE><I>P</I></CODE> is applied with the index as first actual argument. </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>mapInd a(1: d 3: a f: e) <SPAN class="keyword">fun</SPAN><SPAN class="variablename"> </SPAN>{<SPAN class="functionname">$</SPAN> I A} A(I) <SPAN class="keyword">end</SPAN>}</CODE></BLOCKQUOTE><P> yields the record <CODE>a(1: d(1) 3: a(3) f: e(f))</CODE> as output. </P></DD><DT><CODE>foldL</CODE> <A name="label221"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>foldL </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE><I>X</I></CODE><CODE> </CODE><CODE>?<I>Y</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DT><CODE>foldR</CODE> <A name="label223"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>foldR </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE><I>X</I></CODE><CODE> </CODE><CODE>?<I>Y</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>Used for <A name="label224"></A><SPAN class="index">folding</SPAN> the fields of <CODE><I>R</I></CODE> by applying the ternary procedure <CODE><I>P</I></CODE>. </P><P> Suppose that <CODE><I>R</I></CODE> has the arity <CODE>[</CODE><CODE><I>F1</I></CODE><CODE> </CODE>...<CODE> </CODE><CODE><I>Fn</I></CODE><CODE>]</CODE>. Applying the left folding procedure <CODE>{Record<SPAN class="keyword">.</SPAN>foldL </CODE><CODE><I>R</I></CODE><CODE> </CODE><CODE><I>P</I></CODE><CODE> </CODE><CODE><I>Z</I></CODE><CODE> </CODE><CODE><I>Out</I></CODE><CODE>}</CODE> reduces to </P><BLOCKQUOTE class="code"><CODE>{</CODE><CODE><I>P</I></CODE><CODE> </CODE>...<CODE> {</CODE><CODE><I>P</I></CODE><CODE> {</CODE><CODE><I>P</I></CODE><CODE> </CODE><CODE><I>Z</I></CODE><CODE> </CODE><CODE><I>R</I></CODE><CODE><SPAN class="keyword">.</SPAN></CODE><CODE><I>F1</I></CODE><CODE>} </CODE><CODE><I>R</I></CODE><CODE><SPAN class="keyword">.</SPAN></CODE><CODE><I>F2</I></CODE><CODE> </CODE>...<CODE> </CODE><CODE><I>R</I></CODE><CODE><SPAN class="keyword">.</SPAN></CODE><CODE><I>Fn</I></CODE><CODE> </CODE><CODE><I>Out</I></CODE><CODE>}</CODE></BLOCKQUOTE><P> The first actual argument of <CODE><I>P</I></CODE> is the accumulator in which the result of the previous application or the start value <CODE><I>Z</I></CODE> is passed. The second actual argument is a field of <CODE><I>R</I></CODE>. </P><P> Besides the left folding procedure there exists a right folding variant. The application <CODE>{Record<SPAN class="keyword">.</SPAN>foldR </CODE><CODE><I>R</I></CODE><CODE> </CODE><CODE><I>P</I></CODE><CODE> </CODE><CODE><I>Z</I></CODE><CODE> </CODE><CODE><I>Out</I></CODE><CODE>}</CODE> reduces to </P><BLOCKQUOTE class="code"><CODE>{</CODE><CODE><I>P</I></CODE><CODE> </CODE><CODE><I>R</I></CODE><CODE><SPAN class="keyword">.</SPAN></CODE><CODE><I>F1</I></CODE><CODE> {</CODE><CODE><I>P</I></CODE><CODE> </CODE><CODE><I>R</I></CODE><CODE><SPAN class="keyword">.</SPAN></CODE><CODE><I>F2</I></CODE><CODE> </CODE>...<CODE> {</CODE><CODE><I>P</I></CODE><CODE> </CODE><CODE><I>R</I></CODE><CODE><SPAN class="keyword">.</SPAN></CODE><CODE><I>Fn</I></CODE><CODE> </CODE><CODE><I>Z</I></CODE><CODE>} </CODE>...<CODE> </CODE><CODE><I>Out</I></CODE><CODE>}</CODE></BLOCKQUOTE><P> The first actual argument of <CODE><I>P</I></CODE> is a field of <CODE><I>R</I></CODE>; the second actual argument is the accumulator in which the result of the previous application or the start value <CODE><I>Z</I></CODE> is passed. </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>foldL a(3 a: 7 b: 4) <SPAN class="keyword">fun</SPAN><SPAN class="variablename"> </SPAN>{<SPAN class="functionname">$</SPAN> Xr X} X<SPAN class="keyword">|</SPAN>Xr <SPAN class="keyword">end</SPAN> nil}</CODE></BLOCKQUOTE><P> yields the output <CODE>[4 7 3]</CODE>, whereas </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>foldR a(3 a: 7 b: 4) <SPAN class="keyword">fun</SPAN><SPAN class="variablename"> </SPAN>{<SPAN class="functionname">$</SPAN> X Xr} X<SPAN class="keyword">|</SPAN>Xr <SPAN class="keyword">end</SPAN> nil}</CODE></BLOCKQUOTE><P> yields the output <CODE>[3 7 4]</CODE>. </P></DD><DT><CODE>foldLInd</CODE> <A name="label226"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>foldLInd </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE><I>X</I></CODE><CODE> </CODE><CODE>?<I>Y</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DT><CODE>foldRInd</CODE> <A name="label228"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>foldRInd </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE><I>X</I></CODE><CODE> </CODE><CODE>?<I>Y</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>are similar to <CODE>Record<SPAN class="keyword">.</SPAN>foldL</CODE> and <CODE>Record<SPAN class="keyword">.</SPAN>foldR</CODE>, but the 4-ary procedure <CODE><I>P</I></CODE> is applied with the current index as first actual argument. </P></DD><DT><CODE>forAll</CODE> <A name="label230"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>forAll </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>+<I>PO</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>applies the unary procedure or object <CODE><I>PO</I></CODE> to each field of <CODE><I>R</I></CODE>. </P><P> Suppose that the arity of <CODE><I>R</I></CODE> is <CODE>[</CODE><CODE><I>F1</I></CODE><CODE> </CODE>...<CODE> </CODE><CODE><I>Fn</I></CODE><CODE>]</CODE>. The application <CODE>{Record<SPAN class="keyword">.</SPAN>forAll </CODE><CODE><I>R</I></CODE><CODE> </CODE><CODE><I>P</I></CODE><CODE>}</CODE> reduces to the sequence of statements </P><BLOCKQUOTE class="code"><CODE>{</CODE><CODE><I>P</I></CODE><CODE> </CODE><CODE><I>R</I></CODE><CODE><SPAN class="keyword">.</SPAN></CODE><CODE><I>F1</I></CODE><CODE>} </CODE>...<CODE> {</CODE><CODE><I>P</I></CODE><CODE> </CODE><CODE><I>R</I></CODE><CODE><SPAN class="keyword">.</SPAN></CODE><CODE><I>Fn</I></CODE><CODE>}</CODE></BLOCKQUOTE><P> </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>forAll O1<SPAN class="keyword">#</SPAN>O2<SPAN class="keyword">#</SPAN>O3 <SPAN class="keyword">proc</SPAN><SPAN class="variablename"> </SPAN>{<SPAN class="functionname">$</SPAN> O} {O <SPAN class="keyword">do</SPAN>()} <SPAN class="keyword">end</SPAN>}</CODE></BLOCKQUOTE><P> sends the message <CODE><SPAN class="keyword">do</SPAN>()</CODE> to the objects <CODE>O1</CODE>, <CODE>O2</CODE>, and <CODE>O3</CODE>. </P></DD><DT><CODE>forAllInd</CODE> <A name="label232"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>forAllInd </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>is similar to <CODE>Record<SPAN class="keyword">.</SPAN>forAll</CODE>, but the binary procedure <CODE><I>P</I></CODE> is applied with the current index as first actual argument. </P><P> For example, assuming <CODE>O1</CODE>, <CODE>O2</CODE>, and <CODE>O3</CODE> are objects, </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>forAllInd a(<SPAN class="keyword">do</SPAN>: O1 stop: O2 run: O3)<BR> <SPAN class="keyword">proc</SPAN><SPAN class="variablename"> </SPAN>{<SPAN class="functionname">$</SPAN> M O} {O M} <SPAN class="keyword">end</SPAN>}</CODE></BLOCKQUOTE><P> sends the message <CODE><SPAN class="keyword">do</SPAN></CODE> to the object <CODE>O1</CODE>, the message <CODE>stop</CODE> to <CODE>O2</CODE>, and the message <CODE>run</CODE> to <CODE>O3</CODE>. </P></DD><DT><CODE>all</CODE> <A name="label234"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>all </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>B</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DT><CODE>some</CODE> <A name="label236"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>some </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>B</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>tests whether the unary boolean function <CODE><I>P</I></CODE> yields <CODE><SPAN class="keyword">true</SPAN></CODE> when applied to all fields resp. some field of <CODE><I>R</I></CODE>. Stops at the first field for which <CODE><I>P</I></CODE> yields <CODE><SPAN class="keyword">false</SPAN></CODE> resp. <CODE><SPAN class="keyword">true</SPAN></CODE>. The fields are tested in the order given by <CODE>Arity</CODE> (which see). </P></DD><DT><CODE>allInd</CODE> <A name="label238"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>allInd </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>B</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DT><CODE>someInd</CODE> <A name="label240"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>someInd </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>B</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>is similar to <CODE>Record<SPAN class="keyword">.</SPAN>all</CODE> resp. <CODE>Record<SPAN class="keyword">.</SPAN>some</CODE>, but the binary boolean function <CODE><I>P</I></CODE> is applied with the current index as first actual argument. </P></DD><DT><CODE>filter</CODE> <A name="label242"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>filter </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DT><CODE>partition</CODE> <A name="label244"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>partition </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE> </CODE><CODE>?<I>R3</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P><CODE>Record<SPAN class="keyword">.</SPAN>filter</CODE> computes a record <CODE><I>R2</I></CODE> which contains all the features and fields of the record <CODE><I>R1</I></CODE> for which the unary boolean procedure <CODE><I>P</I></CODE> applied to the field yields <CODE><SPAN class="keyword">true</SPAN></CODE>. <CODE>Record<SPAN class="keyword">.</SPAN>partition</CODE> works similarly, but returns in <CODE><I>R3</I></CODE> a record with all remaining fields of <CODE><I>R1</I></CODE>. </P><P> For example, the application </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>partition a(1 4 7 a: 3 b: 6 c: 5) IsOdd ?R2 ?R3}</CODE></BLOCKQUOTE><P> returns <CODE>a(1: 1 3: 7 a: 3 c: 5)</CODE> in <CODE>R2</CODE> and <CODE>a(2: 4 b: 6)</CODE> in <CODE>R3</CODE>. </P></DD><DT><CODE>filterInd</CODE> <A name="label246"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>filterInd </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DT><CODE>partitionInd</CODE> <A name="label248"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>partitionInd </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE> </CODE><CODE>?<I>R3</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>are similar to <CODE>Record<SPAN class="keyword">.</SPAN>filter</CODE> and <CODE>Record<SPAN class="keyword">.</SPAN>partition</CODE>, but the binary boolean function <CODE><I>P</I></CODE> is applied with the current index as first actual argument. </P></DD><DT><CODE>takeWhile</CODE> <A name="label250"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>takeWhile </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DT><CODE>dropWhile</CODE> <A name="label252"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>dropWhile </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R3</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DT><CODE>takeDropWhile</CODE> <A name="label254"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>takeDropWhile </CODE><CODE>+<I>R2</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE> </CODE><CODE>?<I>R3</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>While <CODE>Record<SPAN class="keyword">.</SPAN>filter</CODE> selects all fields and features of a record which satisfy a certain condition, the procedure <CODE>Record<SPAN class="keyword">.</SPAN>takeWhile</CODE> selects only the starting sequence of features and fields which fulfill this condition. The procedure <CODE>Record<SPAN class="keyword">.</SPAN>dropWhile</CODE> is dual: It computes a record with the remaining features and fields. <CODE>Record<SPAN class="keyword">.</SPAN>takeWhileDrop</CODE> computes both records. </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>takeWhile a(1 4 7 a: 3 b: 6 c: 5) IsOdd}</CODE></BLOCKQUOTE><P> yields as output <CODE>a(1)</CODE>, whereas </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>dropWhile a(1 4 7 a: 3 b: 6 c: 5) IsOdd}</CODE></BLOCKQUOTE><P> yields <CODE>a(2: 4 3: 7 a: 3 b: 6 c: 5)</CODE> as output. Both records can be computed simultaneously by </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>takeDropWhile a(1 4 7 a: 3 b: 6 c: 5) IsOdd ?R2 ?R3}</CODE></BLOCKQUOTE><P> </P></DD><DT><CODE>takeWhileInd</CODE> <A name="label256"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>takeWhileInd </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DT><CODE>dropWhileInd</CODE> <A name="label258"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>dropWhileInd </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R3</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DT><CODE>takeDropWhileInd</CODE> <A name="label260"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>takeDropWhileInd </CODE><CODE>+<I>R1</I></CODE><CODE> </CODE><CODE>+<I>P</I></CODE><CODE> </CODE><CODE>?<I>R2</I></CODE><CODE> </CODE><CODE>?<I>R3</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>are similar to <CODE>Record<SPAN class="keyword">.</SPAN>takeWhile</CODE>, <CODE>Record<SPAN class="keyword">.</SPAN>dropWhile</CODE> and <CODE>Record<SPAN class="keyword">.</SPAN>takeDropWhile</CODE> but the binary boolean function <CODE><I>P</I></CODE> is applied with the current index as first actual argument. </P></DD><DT><CODE>waitOr</CODE> <A name="label262"></A> </DT><DD><BLOCKQUOTE class="synopsis"><P><CODE>{Record<SPAN class="keyword">.</SPAN>waitOr </CODE><CODE>+<I>R</I></CODE><CODE> </CODE><CODE>?<I>LI</I></CODE><CODE>}</CODE> </P></BLOCKQUOTE></DD><DD><P>blocks until at least one field of <CODE>+<I>R</I></CODE> is determined. Returns the feature <CODE><I>LI</I></CODE> of a determined field. Raises an exception if <CODE><I>R</I></CODE> is not a proper record, that is, if <CODE><I>R</I></CODE> is a literal. </P><P> For example, </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>waitOr a(_ b: 1)}</CODE></BLOCKQUOTE><P> returns <CODE>b</CODE> while </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>waitOr a(2 b: _)}</CODE></BLOCKQUOTE><P> returns <CODE>1</CODE>, and </P><BLOCKQUOTE class="code"><CODE>{Record<SPAN class="keyword">.</SPAN>waitOr a(_ b: _)}</CODE></BLOCKQUOTE><P> blocks. </P></DD></DL><P> </P></DIV><TABLE align="center" border="0" cellpadding="6" cellspacing="6" class="nav"><TR bgcolor="#DDDDDD"><TD><A href="node8.html">- Up -</A></TD><TD><A href="tuple.html#section.records.tuples">Next >></A></TD></TR></TABLE><HR><ADDRESS><A href="http://www.ps.uni-sb.de/~duchier/">Denys Duchier</A>, <A href="http://www.ps.uni-sb.de/~kornstae/">Leif Kornstaedt</A> and <A href="http://www.ps.uni-sb.de/~schulte/">Christian Schulte</A><BR><SPAN class="version">Version 1.4.0 (20090610)</SPAN></ADDRESS></BODY></HTML>
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