[mod] ast

webapp/lsp/ast/ast.xqm

@@ -0,0 +1,56 @@
+(: Abstract syntax tree
+@author Andy Bunce
+:)
+module namespace ast="lsp/ast";
+(: import module namespace p="xq4" at "xq4.xqm"; :)
+import module namespace xq4="java:quodatum.parser.xq4";
+
+(:~ build :)
+declare function ast:build($text as xs:string,$uri as xs:string:="")
+as element(*){
+ let $xml:= xq4:parseModule($text)=>prof:time("⏱️ p:parse-Module " || $uri)
+ return ($xml,
+        message(ast:report($xml),"REP"),
+        message(ast:report(ast:flatten($xml)),"flat")
+        )
+};
+
+(:~ 
+ :concrete to abstract: simplify by omitting elements with only one child
+:)
+declare function ast:flatten($input as element()) as element() {
+  if (1=count($input/*)) then ast:flatten($input/*)
+  else element {node-name($input) }
+      {$input/@*,
+       for $child in $input/node()
+          return
+             if ($child instance of element())
+                then ast:flatten($child)
+                else $child
+      }
+};
+
+(:-------------------------------------------:)
+
+declare function ast:report($el as element(*))  {
+<analysis>
+        <total-elements>{count($el//element())}</total-elements>
+        <max-depth>{ast:max-node-depth($el)}</max-depth>
+    </analysis>
+};
+
+declare function ast:max-depth($nodes as node()*) as xs:integer {
+    if (empty($nodes)) then 0
+    else
+        max((
+            for $node in $nodes
+            return
+                if ($node instance of element())
+                then ast:max-depth($node/node()) + 1
+                else ast:max-depth($node/node())
+        ))
+};
+
+declare function ast:max-node-depth($root as node()) as xs:integer {
+    ast:max-depth($root)
+};