From fdbc71e9773701a9d41e66a8d81a298ce7ccbfc4 Mon Sep 17 00:00:00 2001
From: John Kerl <kerl.john.r@gmail.com>
Date: Sun, 18 Sep 2016 17:39:40 -0700
Subject: [PATCH] recursion UTs

---
 c/reg_test/expected/out | 92 +++++++++++++++++++++++++++++++++++++++++
 c/reg_test/run          | 40 ++++++++++++++++++
 2 files changed, 132 insertions(+)

diff --git a/c/reg_test/expected/out b/c/reg_test/expected/out
index d3dfdf11d..c7e884a81 100644
--- a/c/reg_test/expected/out
+++ b/c/reg_test/expected/out
@@ -33376,6 +33376,98 @@ zee wye 8  0.5985540091064224  0.976181385699006   1008 2008
 hat wye 9  0.03144187646093577 0.7495507603507059  1009 2009
 pan wye 10 0.5026260055412137  0.9526183602969864  1010 2010
 
+mlr --opprint --from ./reg_test/input/abixy put 
+    func f(n) {
+        if (isnumeric(n)) {
+            if (n > 0) {
+                return n * f(n-1)
+            } else {
+                return 1
+            }
+        }
+        # implicitly return absent
+    }
+    $o = f(NR)
+
+a   b   i  x                   y                   o
+pan pan 1  0.3467901443380824  0.7268028627434533  1
+eks pan 2  0.7586799647899636  0.5221511083334797  2
+wye wye 3  0.20460330576630303 0.33831852551664776 6
+eks wye 4  0.38139939387114097 0.13418874328430463 24
+wye pan 5  0.5732889198020006  0.8636244699032729  120
+zee pan 6  0.5271261600918548  0.49322128674835697 720
+eks zee 7  0.6117840605678454  0.1878849191181694  5040
+zee wye 8  0.5985540091064224  0.976181385699006   40320
+hat wye 9  0.03144187646093577 0.7495507603507059  362880
+pan wye 10 0.5026260055412137  0.9526183602969864  3628800
+
+mlr --opprint --from ./reg_test/input/abixy head -n 5 then put 
+    subr s(n) {
+        print "n = " . n;
+        if (isnumeric(n)) {
+            if (n > 0) {
+                call s(n-1)
+            }
+        }
+    }
+    print "";
+    call s(NR)
+
+
+n = 1
+n = 0
+
+n = 2
+n = 1
+n = 0
+
+n = 3
+n = 2
+n = 1
+n = 0
+
+n = 4
+n = 3
+n = 2
+n = 1
+n = 0
+
+n = 5
+n = 4
+n = 3
+n = 2
+n = 1
+n = 0
+a   b   i x                   y
+pan pan 1 0.3467901443380824  0.7268028627434533
+eks pan 2 0.7586799647899636  0.5221511083334797
+wye wye 3 0.20460330576630303 0.33831852551664776
+eks wye 4 0.38139939387114097 0.13418874328430463
+wye pan 5 0.5732889198020006  0.8636244699032729
+
+mlr --from ./reg_test/input/abixy --opprint put 
+  func f(n) {
+    return n+1;
+  }
+  $o1 = f(NR);
+  $o2 = f(f(NR));
+  $o3 = f(f(f(NR)));
+  $o4 = f(f(f(f(NR))));
+  $o5 = f(f(f(f(f(NR)))));
+  $o6 = f(f(f(f(f(f(NR))))));
+
+a   b   i  x                   y                   o1 o2 o3 o4 o5 o6
+pan pan 1  0.3467901443380824  0.7268028627434533  2  3  4  5  6  7
+eks pan 2  0.7586799647899636  0.5221511083334797  3  4  5  6  7  8
+wye wye 3  0.20460330576630303 0.33831852551664776 4  5  6  7  8  9
+eks wye 4  0.38139939387114097 0.13418874328430463 5  6  7  8  9  10
+wye pan 5  0.5732889198020006  0.8636244699032729  6  7  8  9  10 11
+zee pan 6  0.5271261600918548  0.49322128674835697 7  8  9  10 11 12
+eks zee 7  0.6117840605678454  0.1878849191181694  8  9  10 11 12 13
+zee wye 8  0.5985540091064224  0.976181385699006   9  10 11 12 13 14
+hat wye 9  0.03144187646093577 0.7495507603507059  10 11 12 13 14 15
+pan wye 10 0.5026260055412137  0.9526183602969864  11 12 13 14 15 16
+
 
 ================================================================
 MULTI-PART SCRIPTS
diff --git a/c/reg_test/run b/c/reg_test/run
index db2371e94..16176b954 100755
--- a/c/reg_test/run
+++ b/c/reg_test/run
@@ -4666,6 +4666,46 @@ run_mlr --from $indir/abixy put 'subr log() { print "hello record  ". NR } call
 # Test variable-clear at scope exit; test read of unset locals.
 run_mlr --opprint --from $indir/abixy put '$o1 = a; local a=1000+NR; $o2 = a; a=2000+NR; $o3 = a'
 
+# Test recursion
+run_mlr --opprint --from $indir/abixy put '
+    func f(n) {
+        if (isnumeric(n)) {
+            if (n > 0) {
+                return n * f(n-1)
+            } else {
+                return 1
+            }
+        }
+        # implicitly return absent
+    }
+    $o = f(NR)
+'
+
+run_mlr --opprint --from $indir/abixy head -n 5 then put '
+    subr s(n) {
+        print "n = " . n;
+        if (isnumeric(n)) {
+            if (n > 0) {
+                call s(n-1)
+            }
+        }
+    }
+    print "";
+    call s(NR)
+'
+
+run_mlr --from $indir/abixy --opprint put '
+  func f(n) {
+    return n+1;
+  }
+  $o1 = f(NR);
+  $o2 = f(f(NR));
+  $o3 = f(f(f(NR)));
+  $o4 = f(f(f(f(NR))));
+  $o5 = f(f(f(f(f(NR)))));
+  $o6 = f(f(f(f(f(f(NR))))));
+'
+
 # ----------------------------------------------------------------
 announce MULTI-PART SCRIPTS