Align ordering of rolluprecursive with simple grouping (#23)

docs/odata-data-aggregation-ext/odata-data-aggregation-ext.html

@@ -157,7 +157,7 @@ <h4 id="key-words">Key words:</h4>
 <h4 id="citation-format">Citation format:</h4>
 <p>When referencing this specification the following citation format should be used:</p>
 <p><strong>[OData-Data-Agg-v4.0]</strong></p>
-<p><em>OData Extension for Data Aggregation Version 4.0</em>. Edited by Ralf Handl, Hubert Heijkers, Gerald Krause, Michael Pizzo, Heiko Theißen, and Martin Zurmuehl. 28 June 2023. OASIS Committee Specification Draft 04. <a href="https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/csd04/odata-data-aggregation-ext-v4.0-csd04.html">https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/csd04/odata-data-aggregation-ext-v4.0-csd04.html</a>. Latest stage: <a href="https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/odata-data-aggregation-ext-v4.0.html">https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/odata-data-aggregation-ext-v4.0.html</a>.</p>
+<p><em>OData Extension for Data Aggregation Version 4.0</em>. Edited by Ralf Handl, Hubert Heijkers, Gerald Krause, Michael Pizzo, Heiko Theißen, and Martin Zurmuehl. 28 June 2023. Committee Specification Draft 04. <a href="https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/csd04/odata-data-aggregation-ext-v4.0-csd04.html">https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/csd04/odata-data-aggregation-ext-v4.0-csd04.html</a>. Latest stage: <a href="https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/odata-data-aggregation-ext-v4.0.html">https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/odata-data-aggregation-ext-v4.0.html</a>.</p>
 <h4 id="notices">Notices</h4>
 <p>Copyright © OASIS Open 2023. All Rights Reserved.</p>
 <p>Distributed under the terms of the OASIS <a href="https://www.oasis-open.org/policies-guidelines/ipr/">IPR Policy</a>.</p>
@@ -2750,7 +2750,7 @@ <h2 id="56-functions-on-aggregated-entities"><a name="FunctionsonAggregatedEntit
 <hr />
 <h1 id="6-hierarchical-transformations"><a name="HierarchicalTransformations" href="#HierarchicalTransformations">6 Hierarchical Transformations</a></h1>
 <p>The transformations and the <code>rolluprecursive</code> operator defined in this section are called hierarchical, because they make use of a recursive hierarchy and are defined in terms of hierarchy functions introduced in the previous section.</p>
-<p>With the exceptions of <code>traverse</code> and <code>rolluprecursive</code> whose fourth parameter ends with <code>traverse</code>, the hierarchical transformations do not define an order on the output set. An order can be reinstated by a subsequent <code>orderby</code> or <code>traverse</code> transformation or a <code>$orderby</code>.</p>
+<p>The transformations <code>ancestors</code> and <code>descendants</code> do not define an order on the output set. An order can be imposed by a subsequent <code>orderby</code> or <code>traverse</code> transformation or a <code>$orderby</code>. The output set of <code>traverse</code> is in preorder or postorder, and grouping with <code>rolluprecursive</code> orders its output set in analogy with <a href="#SimpleGrouping">simple grouping</a>.</p>
 <p>The algorithmic descriptions of the transformations make use of a <em>union</em> of collections, this is defined as an unordered collection containing the items from all these collections and from which duplicates have been removed.</p>
 <p>The notation <span class="math inline">\(u[t]\)</span> is used to denote the value of a property <span class="math inline">\(t\)</span>, possibly preceded by a type-cast segment, in an instance <span class="math inline">\(u\)</span>. It is also used to denote the value of a single-valued data aggregation path <span class="math inline">\(t\)</span>, evaluated relative to <span class="math inline">\(u\)</span>. The value of a collection-valued <a href="#DataAggregationPath">data aggregation path</a> is denoted in the <a href="#EvaluationofDataAggregationPaths"><span class="math inline">\(\Gamma\)</span> notation</a> by <span class="math inline">\(γ(u,t)\)</span>.</p>
 <p>The notations introduced here are used throughout the following subsections.</p>
@@ -2949,11 +2949,12 @@ <h2 id="63-grouping-with-rolluprecursive"><a name="Groupingwithrolluprecursive"
 <p>Let <span class="math inline">\(T\)</span> be a transformation sequence, <span class="math inline">\(P_1\)</span> stand in for zero or more property paths and <span class="math inline">\(P_2\)</span> for zero or more <code>rollup</code> or <code>rolluprecursive</code> operators or property paths. The transformation <span class="math inline">\({\tt groupby}((P_1,{\tt rolluprecursive}(H,Q,p,S),P_2),T)\)</span> is computed by the following algorithm, which invokes itself recursively if the number of <code>rolluprecursive</code> operators in the first argument of the <code>groupby</code> transformation, which is called <span class="math inline">\(M\)</span>, is greater than one. Let <span class="math inline">\(N\)</span> be the recursion depth of the algorithm, starting with 1.</p>
 <p><em>The <code>rolluprecursive</code> algorithm:</em></p>
 <p>A property <span class="math inline">\(χ_N\)</span> appears in the algorithm, but is not present in the output set. It is explained later (see <a href="#rollupnode">example 66</a>). <span class="math inline">\(Z_N\)</span> is a transformation whose output set is its input set with property <span class="math inline">\(χ_N\)</span> removed.</p>
-<p>Let <span class="math inline">\(x_1,…,x_n\)</span> be the nodes in <span class="math inline">\(H&#39;\)</span>, possibly with repetitions. If the optional transformation sequence <span class="math inline">\(S\)</span> ends with a <a href="#Transformationtraverse"><code>traverse</code></a> transformation, as in <a href="#weighted">example 118</a>, the sequence <span class="math inline">\(x_1,…,x_n\)</span> MUST have the preorder or postorder established by that traversal, otherwise its order is arbitrary. Then the transformation <span class="math inline">\({\tt groupby}((P_1,{\tt rolluprecursive}(H,Q,p,S),P_2),T)\)</span> is defined as equivalent to <span class="math display">\[{\tt concat}(R(x_1),…,R(x_n))\]</span> with no order defined on the output set unless <span class="math inline">\(S\)</span> ends with a <code>traverse</code> transformation.</p>
+<p>Let <span class="math inline">\(x_1,…,x_n\)</span> be the nodes in <span class="math inline">\(H&#39;\)</span>, possibly with repetitions. If the optional transformation sequence <span class="math inline">\(S\)</span> ends with a <a href="#Transformationtraverse"><code>traverse</code></a> transformation, as in <a href="#weighted">example 118</a>, the sequence <span class="math inline">\(x_1,…,x_n\)</span> MUST have the preorder or postorder established by that traversal, and the transformation <span class="math inline">\({\tt groupby}((P_1,{\tt rolluprecursive}(H,Q,p,S),P_2),T)\)</span> is defined as equivalent to <span class="math display">\[{\tt concat}(R(x_1),…,R(x_n)).\]</span></p>
+<p>Otherwise, if <span class="math inline">\(S\)</span> is not specified or does not end with a <code>traverse</code> transformation, the output set of the transformation <span class="math inline">\({\tt groupby}((P_1,{\tt rolluprecursive}(H,Q,p,S),P_2),T)\)</span> is the concatenation of <span class="math inline">\(R(x_1),…,R(x_n)\)</span>. The order of occurrences from the same <span class="math inline">\(R(x_i)\)</span> remains the same, and no order is defined between occurrences from different <span class="math inline">\(R(x_i)\)</span> and <span class="math inline">\(R(x_j)\)</span>.</p>
 <p><span class="math inline">\(R(x)\)</span> is a transformation that processes the entire sub-hierarchy rooted at <span class="math inline">\(x\)</span>, which is the output set of <span class="math inline">\(F(x)\)</span>. The output set of <span class="math inline">\(R(x)\)</span> is a collection of aggregated instances for all rollup results.</p>
-<p>If at least one of <span class="math inline">\(P_1\)</span> or <span class="math inline">\(P_2\)</span> is non-empty, then <span class="math display">\[R(x)=F(x)/{\tt compute}(x{\tt\ as\ }χ_N)/{\tt groupby}((P_1,P_2),T/Z_N/\Pi_G(σ(x)))\]</span> with no order defined on the output set.</p>
+<p>If at least one of <span class="math inline">\(P_1\)</span> or <span class="math inline">\(P_2\)</span> is non-empty, then <span class="math display">\[R(x)=F(x)/{\tt compute}(x{\tt\ as\ }χ_N)/{\tt groupby}((P_1,P_2),T/Z_N/\Pi_G(σ(x))).\]</span></p>
 <p>The property <span class="math inline">\(χ_N=x\)</span> is present during the evaluation of <span class="math inline">\(T\)</span>, but not afterwards. If <span class="math inline">\(P_2\)</span> contains a <code>rolluprecursive</code> operator, the evaluation of the formula involves a recursive invocation (with <span class="math inline">\(N\)</span> increased by 1) of the <code>rolluprecursive</code> algorithm.</p>
-<p>Otherwise if <span class="math inline">\(P_1\)</span> and <span class="math inline">\(P_2\)</span> are empty, then <span class="math display">\[R(x)=F(x)/{\tt compute}(x{\tt\ as\ }χ_N)/T/Z_N/\Pi_G(σ(x))\]</span> with no order defined on the output set.</p>
+<p>Otherwise if <span class="math inline">\(P_1\)</span> and <span class="math inline">\(P_2\)</span> are empty, then <span class="math display">\[R(x)=F(x)/{\tt compute}(x{\tt\ as\ }χ_N)/T/Z_N/\Pi_G(σ(x)).\]</span></p>
 <p><span class="math inline">\(F(x)\)</span> is defined as follows: If <span class="math inline">\(p\)</span> contains only single-valued segments, then <span class="math display">\[\matrix{ F(x)={\tt filter}(\hbox{\tt Aggregation.isdescendant}(\hfill\\ \quad {\tt HierarchyNodes}=H,\;{\tt HierarchyQualifier}=\hbox{\tt{&#39;$Q$&#39;}},\hfill\\ \quad {\tt Node}=p,\;{\tt Ancestor}=x[q],\;{\tt IncludeSelf}={\tt true})).\hfill }\]</span></p>
 <p>Otherwise <span class="math inline">\(p=p_1/…/p_k/r\)</span> with <span class="math inline">\(k≥1\)</span> and <span class="math display">\[\matrix{ F(x)={\tt filter}(\hfill\\ \hskip1pc p_1/{\tt any}(y_1:\hfill\\ \hskip2pc y_1/p_2/{\tt any}(y_2:\hfill\\ \hskip3pc ⋱\hfill\\ \hskip4pc y_{k-1}/p_k/{\tt any}(y_k:\hfill\\ \hskip5pc \hbox{\tt Aggregation.isdescendant}(\hfill\\ \hskip6pc {\tt HierarchyNodes}=H,\;{\tt HierarchyQualifier}=\hbox{\tt{&#39;$Q$&#39;}},\hfill\\ \hskip6pc {\tt Node}=y_k/r,\;{\tt Ancestor}=x[q],\;{\tt IncludeSelf}={\tt true}\hfill\\ \hskip5pc )\hfill\\ \hskip4pc )\hfill\\ \hskip3pc ⋰\hfill\\ \hskip2pc )\hfill\\ \hskip1pc )\hfill\\ )\hfill }\]</span> where <span class="math inline">\(y_1,…,y_k\)</span> denote <code>lambdaVariableExpr</code>s and <span class="math inline">\({}/r\)</span> may be absent. (See <a href="#rollupcoll">example 113</a> for a case with <span class="math inline">\(k=1\)</span>.)</p>
 <p>Informatively speaking, the effect of the algorithm can be summarized as follows: If <span class="math inline">\(M≥1\)</span> and <span class="math inline">\(\hat F_N(x)\)</span> denotes the collection of all instances that are related to a node <span class="math inline">\(x\)</span> as determined by <span class="math inline">\(F(x)\)</span> in the recursive hierarchy of the <span class="math inline">\(N\)</span>-th <code>rolluprecursive</code> operator, then <span class="math inline">\(T\)</span> is applied to each of the intersections of <span class="math inline">\(\hat F_1(χ_1),…,\hat F_M(χ_M)\)</span>, as <span class="math inline">\(χ_N\)</span> runs over all nodes of the <span class="math inline">\(N\)</span>-th recursive hierarchy for <span class="math inline">\(1≤N≤M\)</span>. Into the instances of the resulting output sets the <span class="math inline">\(\Pi_G\)</span> transformations inject information about the nodes <span class="math inline">\(χ_1,…,χ_M\)</span>.</p>

docs/odata-data-aggregation-ext/odata-data-aggregation-ext.md

@@ -82,7 +82,7 @@ When referencing this specification the following citation format should be used
 **[OData-Data-Agg-v4.0]**
 
 _OData Extension for Data Aggregation Version 4.0_.
-Edited by Ralf Handl, Hubert Heijkers, Gerald Krause, Michael Pizzo, Heiko Theißen, and Martin Zurmuehl. 28 June 2023. OASIS Committee Specification Draft 04.
+Edited by Ralf Handl, Hubert Heijkers, Gerald Krause, Michael Pizzo, Heiko Theißen, and Martin Zurmuehl. 28 June 2023. Committee Specification Draft 04.
 https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/csd04/odata-data-aggregation-ext-v4.0-csd04.html.
 Latest stage: https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/odata-data-aggregation-ext-v4.0.html.
 
@@ -2672,7 +2672,7 @@ Example 59: assume the product is an implicit input for a function bound to a co
 
 The transformations and the `rolluprecursive` operator defined in this section are called hierarchical, because they make use of a recursive hierarchy and are defined in terms of hierarchy functions introduced in the previous section.
 
-With the exceptions of `traverse` and `rolluprecursive` whose fourth parameter ends with `traverse`, the hierarchical transformations do not define an order on the output set. An order can be reinstated by a subsequent `orderby` or `traverse` transformation or a `$orderby`.
+The transformations `ancestors` and `descendants` do not define an order on the output set. An order can be imposed by a subsequent `orderby` or `traverse` transformation or a `$orderby`. The output set of `traverse` is in preorder or postorder, and grouping with `rolluprecursive` orders its output set in analogy with [simple grouping](#SimpleGrouping).
 
 The algorithmic descriptions of the transformations make use of a _union_ of collections, this is defined as an unordered collection containing the items from all these collections and from which duplicates have been removed.
 
@@ -2974,21 +2974,20 @@ _The `rolluprecursive` algorithm:_
 
 A property $χ_N$ appears in the algorithm, but is not present in the output set. It is explained later (see [example 66](#rollupnode)). $Z_N$ is a transformation whose output set is its input set with property $χ_N$ removed.
 
-Let $x_1,…,x_n$ be the nodes in $H'$, possibly with repetitions. If the optional transformation sequence $S$ ends with a [`traverse`](#Transformationtraverse) transformation, as in [example 118](#weighted), the sequence $x_1,…,x_n$ MUST have the preorder or postorder established by that traversal, otherwise its order is arbitrary. Then the transformation ${\tt groupby}((P_1,{\tt rolluprecursive}(H,Q,p,S),P_2),T)$ is defined as equivalent to
-$${\tt concat}(R(x_1),…,R(x_n))$$
-with no order defined on the output set unless $S$ ends with a `traverse` transformation.
+Let $x_1,…,x_n$ be the nodes in $H'$, possibly with repetitions. If the optional transformation sequence $S$ ends with a [`traverse`](#Transformationtraverse) transformation, as in [example 118](#weighted), the sequence $x_1,…,x_n$ MUST have the preorder or postorder established by that traversal, and the transformation ${\tt groupby}((P_1,{\tt rolluprecursive}(H,Q,p,S),P_2),T)$ is defined as equivalent to
+$${\tt concat}(R(x_1),…,R(x_n)).$$
+
+Otherwise, if $S$ is not specified or does not end with a `traverse` transformation, the output set of the transformation ${\tt groupby}((P_1,{\tt rolluprecursive}(H,Q,p,S),P_2),T)$ is the concatenation of $R(x_1),…,R(x_n)$. The order of occurrences from the same $R(x_i)$ remains the same, and no order is defined between occurrences from different $R(x_i)$ and $R(x_j)$.
 
 $R(x)$ is a transformation that processes the entire sub-hierarchy rooted at $x$, which is the output set of $F(x)$. The output set of $R(x)$ is a collection of aggregated instances for all rollup results.
 
 If at least one of $P_1$ or $P_2$ is non-empty, then
-$$R(x)=F(x)/{\tt compute}(x{\tt\ as\ }χ_N)/{\tt groupby}((P_1,P_2),T/Z_N/\Pi_G(σ(x)))$$
-with no order defined on the output set.
+$$R(x)=F(x)/{\tt compute}(x{\tt\ as\ }χ_N)/{\tt groupby}((P_1,P_2),T/Z_N/\Pi_G(σ(x))).$$
 
 The property $χ_N=x$ is present during the evaluation of $T$, but not afterwards. If $P_2$ contains a `rolluprecursive` operator, the evaluation of the formula involves a recursive invocation (with $N$ increased by 1) of the `rolluprecursive` algorithm.
 
 Otherwise if $P_1$ and $P_2$ are empty, then
-$$R(x)=F(x)/{\tt compute}(x{\tt\ as\ }χ_N)/T/Z_N/\Pi_G(σ(x))$$
-with no order defined on the output set.
+$$R(x)=F(x)/{\tt compute}(x{\tt\ as\ }χ_N)/T/Z_N/\Pi_G(σ(x)).$$
 
 $F(x)$ is defined as follows: If $p$ contains only single-valued segments, then
 $$\matrix{ F(x)={\tt filter}(\hbox{\tt Aggregation.isdescendant}(\hfill\\ \quad {\tt HierarchyNodes}=H,\;{\tt HierarchyQualifier}=\hbox{\tt{'$Q$'}},\hfill\\ \quad {\tt Node}=p,\;{\tt Ancestor}=x[q],\;{\tt IncludeSelf}={\tt true})).\hfill }$$

lib/server.js

@@ -9,9 +9,10 @@ var app = express()
   .get("/*", function (req, res, next) {
     if (req.path.endsWith("/")) {
       try {
-        req.query["-T"] = execSync("git branch --show-current", {
+        var branch = execSync("git branch --show-current", {
           cwd: __dirname,
         }).toString();
+        if (branch) req.query["-T"] = branch;
       } catch (e) {}
       var dir = req.params[0].substring(0, req.params[0].length - 1);
       try {

odata-data-aggregation-ext/0 frontmatter.md

@@ -82,7 +82,7 @@ When referencing this specification the following citation format should be used
 **[OData-Data-Agg-v4.0]**
 
 _$$$pagetitle$$$_.
-Edited by Ralf Handl, Hubert Heijkers, Gerald Krause, Michael Pizzo, Heiko Theißen, and Martin Zurmuehl. $$$pubdate$$$. OASIS Committee Specification Draft 04.
+Edited by Ralf Handl, Hubert Heijkers, Gerald Krause, Michael Pizzo, Heiko Theißen, and Martin Zurmuehl. $$$pubdate$$$. $$$subtitle$$$.
 https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/csd04/odata-data-aggregation-ext-v4.0-csd04.html.
 Latest stage: https://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/odata-data-aggregation-ext-v4.0.html.