grt-algos: clarify the API

3 files changed, 11 insertions, 6 deletions

diff --git a/src/grt/grt-algos.adb b/src/grt/grt-algos.adb
index 6469e2b80..82c14bd8c 100644
--- a/src/grt/grt-algos.adb
+++ b/src/grt/grt-algos.adb
@@ -39,6 +39,9 @@ package body Grt.Algos is
       end Bubble_Down;
 
    begin
+      --  Note: if N < 2, there is nothing to sort.  The loops are not
+      --  executed.
+
       --  Heapify
       for I in reverse 1 .. N / 2 loop
          Bubble_Down (I, N);
diff --git a/src/grt/grt-algos.ads b/src/grt/grt-algos.ads
index 1197bcd7b..828960e11 100644
--- a/src/grt/grt-algos.ads
+++ b/src/grt/grt-algos.ads
@@ -15,12 +15,12 @@
 --  along with this program.  If not, see <gnu.org/licenses>.
 
 package Grt.Algos is
-   --  Heap sort the N elements.
+   --  Heap sort the N elements.  Indexes are from 1 to N.
    generic
-      --  Compare two elements, return true iff OP1 < OP2.
-      with function Lt (Op1, Op2 : Natural) return Boolean;
+      --  Compare two elements, return true iff L < R.
+      with function Lt (L, R : Positive) return Boolean;
 
       --  Swap two elements.
-      with procedure Swap (From : Natural; To : Natural);
+      with procedure Swap (P1 : Positive; P2 : Positive);
    procedure Heap_Sort (N : Natural);
 end Grt.Algos;
diff --git a/src/grt/grt-waves.adb b/src/grt/grt-waves.adb
index eb0f0a898..98a8538b3 100644
--- a/src/grt/grt-waves.adb
+++ b/src/grt/grt-waves.adb
@@ -1783,7 +1783,8 @@ package body Grt.Waves is
 
    procedure Wave_Cycle
    is
-      function Lt (Op1, Op2 : Natural) return Boolean is
+      function Lt (Op1, Op2 : Positive) return Boolean
+      is
          Left : Ghdl_Signal_Ptr;
          Right : Ghdl_Signal_Ptr;
       begin
@@ -1793,7 +1794,8 @@ package body Grt.Waves is
       end Lt;
       pragma Inline (Lt);
 
-      procedure Swap (From, To : Natural) is
+      procedure Swap (From, To : Positive)
+      is
          Tmp : Ghdl_Signal_Ptr;
       begin
          Tmp := Changed_Sig_Table.Table (From);