feat(*): recreate library as scoped package

base/mp_recursivejoin.sas

@@ -0,0 +1,90 @@
+/**
+  @file
+  @brief Returns all children from a hierarchy table for a specified parent
+  @details Where data stores hierarchies in a simple parent / child mapping,
+    it is not always straightforward to extract all the children for a
+    particular parent.  This problem is known as a recursive self join.  This
+    macro will extract all the descendents for a parent.
+  Usage:
+
+      data have;
+        p=1;c=2;output;
+        p=2;c=3;output;
+        p=2;c=4;output;
+        p=3;c=5;output;
+        p=6;c=7;output;
+        p=8;c=9;output;
+      run;
+
+      %mp_recursivejoin(base_ds=have
+        ,outds=want
+        ,matchval=1
+        ,parentvar=p
+        ,childvar=c
+        )
+
+  @param base_ds= base table containing hierarchy (not modified)
+  @param outds= the output dataset to create with the generated hierarchy
+  @param matchval= the ultimate parent from which to filter
+  @param parentvar= name of the parent variable
+  @param childvar= name of the child variable (should be same type as parent)
+  @param mdebug= set to 1 to prevent temp tables being dropped
+
+
+  @returns outds contains the following variables:
+   - level (0 = top level)
+   - &parentvar
+   - &childvar (null if none found)
+
+  @version 9.2
+  @author Allan Bowe
+
+**/
+
+%macro mp_recursivejoin(base_ds=
+    ,outds=
+    ,matchval=
+    ,parentvar=
+    ,childvar=
+    ,iter= /* reserved for internal / recursive use by the macro itself */
+    ,maxiter=500 /* avoid infinite loop */
+    ,mDebug=0);
+
+%if &iter= %then %do;
+  proc sql;
+  create table &outds as
+    select 0 as level,&parentvar, &childvar
+    from &base_ds
+    where &parentvar=&matchval;
+  %if &sqlobs.=0 %then %do;
+    %put NOTE: &sysmacroname: No match for &parentvar=&matchval;
+    %return;
+  %end;
+  %let iter=1;
+%end;
+%else %if &iter>&maxiter %then %return;
+
+proc sql;
+create table _data_ as
+  select &iter as level
+    ,curr.&childvar as &parentvar
+    ,base_ds.&childvar as &childvar
+  from &outds curr
+  left join &base_ds base_ds
+  on  curr.&childvar=base_ds.&parentvar
+  where curr.level=%eval(&iter.-1)
+    & curr.&childvar is not null;
+%local append_ds; %let append_ds=&syslast;
+%local obs; %let obs=&sqlobs;
+insert into &outds select distinct * from &append_ds;
+%if &mdebug=0 %then drop table &append_ds;;
+
+%if &obs %then %do;
+  %mp_recursivejoin(iter=%eval(&iter.+1)
+    ,outds=&outds,parentvar=&parentvar
+    ,childvar=&childvar
+    ,base_ds=&base_ds
+    )
+%end;
+
+%mend;