Merge eval-ast and macro expansion into EVAL, add DEBUG-EVAL

See issue kanaka#587.
 * Merge eval-ast and eval into a single conditional.
 * Expand macros during the apply phase, removing lots of duplicate
   tests, and increasing the overall consistency by allowing the macro
   to be computed instead of referenced by name (`((defmacro! cond
   (...)))` is currently illegal for example).
 * Print "EVAL: $ast" at the top of EVAL if DEBUG-EVAL exists in the
   MAL environment.
 * Remove macroexpand and quasiquoteexpand special forms.
 * Use pattern-matching style in process/step*.txt.

c: also fixe defmacro so that it does not mutate functions.

elm: the test failure is most probably unrelated.

groovy: sometimes fail, but not on each rebuild.

nasm: fails some new soft tests, but the issue is unreproducible when
running the interpreter manually.

objpascal: I cannot reproduce the error with a more recent compiler.

ocaml: also remove metadata from symbols.

ruby.2: step9 was failing with REGRESS=1, the fix is now backported
from stepA.

impls/ada.2/envs.adb

@@ -53,6 +53,25 @@ package body Envs is
  return HM.Element (Position);
  end Get;
 
+ function Get_Or_Nil (Env : Instance;
+ Key : Types.String_Ptr) return Types.T is
+ Position : HM.Cursor := Env.Data.Find (Key);
+ Ref : Link;
+ begin
+ if not HM.Has_Element (Position) then
+ Ref := Env.Outer;
+ loop
+ if Ref = null then
+ return Types.Nil;
+ end if;
+ Position := Ref.all.Data.Find (Key);
+ exit when HM.Has_Element (Position);
+ Ref := Ref.all.Outer;
+ end loop;
+ end if;
+ return HM.Element (Position);
+ end Get_Or_Nil;
+
  procedure Keep_References (Object : in out Instance) is
  begin
  for Position in Object.Data.Iterate loop

impls/ada.2/envs.ads

@@ -27,6 +27,9 @@ package Envs is
  function Get (Env : in Instance;
  Key : in Types.String_Ptr) return Types.T;
 
+ function Get_Or_Nil (Env : Instance;
+ Key : Types.String_Ptr) return Types.T;
+
  procedure Set (Env : in out Instance;
  Key : in Types.T;
  New_Item : in Types.T) with Inline;

impls/ada.2/step2_eval.adb

@@ -1,4 +1,3 @@
-with Ada.Environment_Variables;
 with Ada.Containers.Indefinite_Hashed_Maps;
 with Ada.Strings.Hash;
 with Ada.Text_IO.Unbounded_IO;
@@ -14,7 +13,7 @@ with Types.Strings;
 
 procedure Step2_Eval is
 
- Dbgeval : constant Boolean := Ada.Environment_Variables.Exists ("dbgeval");
+ Dbgeval : constant Boolean := False;
 
  use type Types.T;
  use all type Types.Kind_Type;
@@ -53,11 +52,9 @@ procedure Step2_Eval is
  First : Types.T;
  begin
  if Dbgeval then
- Ada.Text_IO.New_Line;
  Ada.Text_IO.Put ("EVAL: ");
  Print (Ast);
  end if;
-
  case Ast.Kind is
  when Kind_Nil | Kind_Atom | Kind_Boolean | Kind_Number | Types.Kind_Key
  | Kind_Macro | Types.Kind_Function =>

impls/ada.2/step3_env.adb

@@ -1,4 +1,3 @@
-with Ada.Environment_Variables;
 with Ada.Text_IO.Unbounded_IO;
 
 with Envs;
@@ -13,7 +12,7 @@ with Types.Strings;
 
 procedure Step3_Env is
 
- Dbgeval : constant Boolean := Ada.Environment_Variables.Exists ("dbgeval");
+ Dbgeval : constant Types.String_Ptr := Types.Strings.Alloc ("DEBUG-EVAL");
 
  use type Types.T;
  use all type Types.Kind_Type;
@@ -45,8 +44,8 @@ procedure Step3_Env is
  is
  First : Types.T;
  begin
- if Dbgeval then
-  Ada.Text_IO.New_Line;
+ <<Restart>>
+ if Types.To_Boolean (Env.all.Get_Or_Nil (Dbgeval)) then
  Ada.Text_IO.Put ("EVAL: ");
  Print (Ast);
  Envs.Dump_Stack (Env.all);
@@ -209,6 +208,7 @@ begin
  -- Collect garbage.
  Err.Data := Types.Nil;
  Repl.all.Keep;
+ Dbgeval.Keep;
  Garbage_Collected.Clean;
  end loop;
  Ada.Text_IO.New_Line;

impls/ada.2/step4_if_fn_do.adb

@@ -1,4 +1,3 @@
-with Ada.Environment_Variables;
 with Ada.Text_IO.Unbounded_IO;
 
 with Core;
@@ -15,7 +14,7 @@ with Types.Strings;
 
 procedure Step4_If_Fn_Do is
 
- Dbgeval : constant Boolean := Ada.Environment_Variables.Exists ("dbgeval");
+ Dbgeval : constant Types.String_Ptr := Types.Strings.Alloc ("DEBUG-EVAL");
 
  use type Types.T;
  use all type Types.Kind_Type;
@@ -47,8 +46,8 @@ procedure Step4_If_Fn_Do is
  is
  First : Types.T;
  begin
- if Dbgeval then
-  Ada.Text_IO.New_Line;
+ <<Restart>>
+ if Types.To_Boolean (Env.all.Get_Or_Nil (Dbgeval)) then
  Ada.Text_IO.Put ("EVAL: ");
  Print (Ast);
  Envs.Dump_Stack (Env.all);
@@ -81,17 +80,13 @@ procedure Step4_If_Fn_Do is
  if First.Str.all = "if" then
  Err.Check (Ast.Sequence.all.Length in 3 .. 4,
  "expected 2 or 3 parameters");
- declare
- Tst : constant Types.T := Eval (Ast.Sequence.all.Data (2), Env);
- begin
- if Tst /= Types.Nil and Tst /= (Kind_Boolean, False) then
- return Eval (Ast.Sequence.all.Data (3), Env);
- elsif Ast.Sequence.all.Length = 3 then
- return Types.Nil;
- else
- return Eval (Ast.Sequence.all.Data (4), Env);
- end if;
- end;
+ if Types.To_Boolean (Eval (Ast.Sequence.all.Data (2), Env)) then
+ return Eval (Ast.Sequence.all.Data (3), Env);
+ elsif Ast.Sequence.all.Length = 3 then
+ return Types.Nil;
+ else
+ return Eval (Ast.Sequence.all.Data (4), Env);
+ end if;
  elsif First.Str.all = "let*" then
  Err.Check (Ast.Sequence.all.Length = 3
  and then Ast.Sequence.all.Data (2).Kind in Types.Kind_Sequence,
@@ -251,6 +246,7 @@ begin
  -- Collect garbage.
  Err.Data := Types.Nil;
  Repl.all.Keep;
+ Dbgeval.Keep;
  Garbage_Collected.Clean;
  end loop;
  Ada.Text_IO.New_Line;

impls/ada.2/step5_tco.adb

@@ -1,4 +1,3 @@
-with Ada.Environment_Variables;
 with Ada.Text_IO.Unbounded_IO;
 
 with Core;
@@ -15,7 +14,7 @@ with Types.Strings;
 
 procedure Step5_Tco is
 
- Dbgeval : constant Boolean := Ada.Environment_Variables.Exists ("dbgeval");
+ Dbgeval : constant Types.String_Ptr := Types.Strings.Alloc ("DEBUG-EVAL");
 
  use type Types.T;
  use all type Types.Kind_Type;
@@ -56,8 +55,7 @@ procedure Step5_Tco is
  First : Types.T;
  begin
  <<Restart>>
- if Dbgeval then
- Ada.Text_IO.New_Line;
+ if Types.To_Boolean (Env.all.Get_Or_Nil (Dbgeval)) then
  Ada.Text_IO.Put ("EVAL: ");
  Print (Ast);
  Envs.Dump_Stack (Env.all);
@@ -90,19 +88,15 @@ procedure Step5_Tco is
  if First.Str.all = "if" then
  Err.Check (Ast.Sequence.all.Length in 3 .. 4,
  "expected 2 or 3 parameters");
- declare
- Tst : constant Types.T := Eval (Ast.Sequence.all.Data (2), Env);
- begin
- if Tst /= Types.Nil and Tst /= (Kind_Boolean, False) then
- Ast := Ast.Sequence.all.Data (3);
- goto Restart;
- elsif Ast.Sequence.all.Length = 3 then
- return Types.Nil;
- else
- Ast := Ast.Sequence.all.Data (4);
- goto Restart;
- end if;
- end;
+ if Types.To_Boolean (Eval (Ast.Sequence.all.Data (2), Env)) then
+ Ast := Ast.Sequence.all.Data (3);
+ goto Restart;
+ elsif Ast.Sequence.all.Length = 3 then
+ return Types.Nil;
+ else
+ Ast := Ast.Sequence.all.Data (4);
+ goto Restart;
+ end if;
  elsif First.Str.all = "let*" then
  Err.Check (Ast.Sequence.all.Length = 3
  and then Ast.Sequence.all.Data (2).Kind in Types.Kind_Sequence,
@@ -284,6 +278,7 @@ begin
  -- Collect garbage.
  Err.Data := Types.Nil;
  Repl.all.Keep;
+ Dbgeval.Keep;
  Garbage_Collected.Clean;
  end loop;
  Ada.Text_IO.New_Line;

impls/ada.2/step6_file.adb

@@ -1,5 +1,4 @@
 with Ada.Command_Line;
-with Ada.Environment_Variables;
 with Ada.Text_IO.Unbounded_IO;
 
 with Core;
@@ -16,7 +15,7 @@ with Types.Strings;
 
 procedure Step6_File is
 
- Dbgeval : constant Boolean := Ada.Environment_Variables.Exists ("dbgeval");
+ Dbgeval : constant Types.String_Ptr := Types.Strings.Alloc ("DEBUG-EVAL");
 
  use type Types.T;
  use all type Types.Kind_Type;
@@ -60,8 +59,7 @@ procedure Step6_File is
  First : Types.T;
  begin
  <<Restart>>
- if Dbgeval then
- Ada.Text_IO.New_Line;
+ if Types.To_Boolean (Env.all.Get_Or_Nil (Dbgeval)) then
  Ada.Text_IO.Put ("EVAL: ");
  Print (Ast);
  Envs.Dump_Stack (Env.all);
@@ -94,19 +92,15 @@ procedure Step6_File is
  if First.Str.all = "if" then
  Err.Check (Ast.Sequence.all.Length in 3 .. 4,
  "expected 2 or 3 parameters");
- declare
- Tst : constant Types.T := Eval (Ast.Sequence.all.Data (2), Env);
- begin
- if Tst /= Types.Nil and Tst /= (Kind_Boolean, False) then
- Ast := Ast.Sequence.all.Data (3);
- goto Restart;
- elsif Ast.Sequence.all.Length = 3 then
- return Types.Nil;
- else
- Ast := Ast.Sequence.all.Data (4);
- goto Restart;
- end if;
- end;
+ if Types.To_Boolean (Eval (Ast.Sequence.all.Data (2), Env)) then
+ Ast := Ast.Sequence.all.Data (3);
+ goto Restart;
+ elsif Ast.Sequence.all.Length = 3 then
+ return Types.Nil;
+ else
+ Ast := Ast.Sequence.all.Data (4);
+ goto Restart;
+ end if;
  elsif First.Str.all = "let*" then
  Err.Check (Ast.Sequence.all.Length = 3
  and then Ast.Sequence.all.Data (2).Kind in Types.Kind_Sequence,
@@ -310,6 +304,7 @@ begin
  -- Collect garbage.
  Err.Data := Types.Nil;
  Repl.all.Keep;
+ Dbgeval.Keep;
  Garbage_Collected.Clean;
  end loop;
  Ada.Text_IO.New_Line;

impls/ada.2/step7_quote.adb

@@ -1,5 +1,4 @@
 with Ada.Command_Line;
-with Ada.Environment_Variables;
 with Ada.Text_IO.Unbounded_IO;
 
 with Core;
@@ -16,7 +15,7 @@ with Types.Strings;
 
 procedure Step7_Quote is
 
- Dbgeval : constant Boolean := Ada.Environment_Variables.Exists ("dbgeval");
+ Dbgeval : constant Types.String_Ptr := Types.Strings.Alloc ("DEBUG-EVAL");
 
  use type Types.T;
  use all type Types.Kind_Type;
@@ -62,8 +61,7 @@ procedure Step7_Quote is
  First : Types.T;
  begin
  <<Restart>>
- if Dbgeval then
- Ada.Text_IO.New_Line;
+ if Types.To_Boolean (Env.all.Get_Or_Nil (Dbgeval)) then
  Ada.Text_IO.Put ("EVAL: ");
  Print (Ast);
  Envs.Dump_Stack (Env.all);
@@ -96,19 +94,15 @@ procedure Step7_Quote is
  if First.Str.all = "if" then
  Err.Check (Ast.Sequence.all.Length in 3 .. 4,
  "expected 2 or 3 parameters");
- declare
- Tst : constant Types.T := Eval (Ast.Sequence.all.Data (2), Env);
- begin
- if Tst /= Types.Nil and Tst /= (Kind_Boolean, False) then
- Ast := Ast.Sequence.all.Data (3);
- goto Restart;
- elsif Ast.Sequence.all.Length = 3 then
- return Types.Nil;
- else
- Ast := Ast.Sequence.all.Data (4);
- goto Restart;
- end if;
- end;
+ if Types.To_Boolean (Eval (Ast.Sequence.all.Data (2), Env)) then
+ Ast := Ast.Sequence.all.Data (3);
+ goto Restart;
+ elsif Ast.Sequence.all.Length = 3 then
+ return Types.Nil;
+ else
+ Ast := Ast.Sequence.all.Data (4);
+ goto Restart;
+ end if;
  elsif First.Str.all = "let*" then
  Err.Check (Ast.Sequence.all.Length = 3
  and then Ast.Sequence.all.Data (2).Kind in Types.Kind_Sequence,
@@ -167,9 +161,6 @@ procedure Step7_Quote is
  Ast => Ast.Sequence.all.Data (3),
  Env => Env));
  end;
- elsif First.Str.all = "quasiquoteexpand" then
- Err.Check (Ast.Sequence.all.Length = 2, "expected 1 parameter");
- return Quasiquote (Ast.Sequence.all.Data (2));
  elsif First.Str.all = "quasiquote" then
  Err.Check (Ast.Sequence.all.Length = 2, "expected 1 parameter");
  Ast := Quasiquote (Ast.Sequence.all.Data (2));
@@ -379,6 +370,7 @@ begin
  -- Collect garbage.
  Err.Data := Types.Nil;
  Repl.all.Keep;
+ Dbgeval.Keep;
  Garbage_Collected.Clean;
  end loop;
  Ada.Text_IO.New_Line;