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Cyclic references were never deallocated by reference conuting. Symbols cannot create cyclic structures and are less frequent (one allocation per symbol), keep reference counting for them. This slightly improves performances even though many previous optimizations are removed (environment stack, reuse of memory). Step caching hash of symbols. This does not seem to improve performances. Hashing them instead of ordering them does. Define Repl in the step file instead of globally. Move the eval built-in function from core into the step file. When possible, pass Ada records instead of explicit pointers. In the reader, construct more objects directly as described in the MAL process, reserve the buffer for sequences and maps In eval, iterate on vectors without delegation. The increased complexity was not improving performances. Keep demonstrating Ada type-safe genericity for maps, where iterating outside Types.Maps would be less easy and/or efficient. In quasiquote_list, concatenate in one buffer instead of allocating a list for each element. The buffer may be reallocated behind the curtain, but not once per element anymore. In environments, illustrate tail call optimization when recursion is more readable than a loop.
55 lines
1.4 KiB
Ada
55 lines
1.4 KiB
Ada
with Ada.Unchecked_Deallocation;
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package body Garbage_Collected is
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procedure Free is new Ada.Unchecked_Deallocation (Class, Pointer);
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Top : Pointer := null;
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----------------------------------------------------------------------
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procedure Clean is
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Current : Pointer := Top;
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Previous : Pointer;
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begin
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while Current /= null and then not Current.all.Kept loop
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Previous := Current;
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Current := Current.all.Next;
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Free (Previous);
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end loop;
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Top := Current;
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while Current /= null loop
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if Current.all.Kept then
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Current.all.Kept := False;
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Previous := Current;
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else
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Previous.all.Next := Current.all.Next;
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Free (Current);
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end if;
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Current := Previous.all.Next;
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end loop;
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end Clean;
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procedure Keep (Object : in out Instance) is
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begin
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if not Object.Kept then
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Object.Kept := True;
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Class (Object).Keep_References; -- dispatching
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end if;
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end Keep;
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procedure Check_Allocations is
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begin
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pragma Assert (Top = null);
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end Check_Allocations;
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procedure Register (Ref : in not null Pointer) is
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begin
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pragma Assert (Ref.all.Kept = False);
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pragma Assert (Ref.all.Next = null);
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Ref.all.Next := Top;
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Top := Ref;
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end Register;
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end Garbage_Collected;
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