From 6dcefcfb716680437575ec19bfbe8d0b44d6a0ec Mon Sep 17 00:00:00 2001
From: Markus Triska <triska@metalevel.at>
Date: Sat, 18 Apr 2020 17:40:19 +0200
Subject: [PATCH 1/3] small simplifications

---
 src/prolog/toplevel.pl | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/src/prolog/toplevel.pl b/src/prolog/toplevel.pl
index f2adba33..09131d6d 100644
--- a/src/prolog/toplevel.pl
+++ b/src/prolog/toplevel.pl
@@ -146,24 +146,22 @@
 
 '$read_input'(ThreadedGoals, NewVarList) :-
     get_single_char(C),
-    (  C == w ->
+    (  C = w ->
        nl,
        write('   '),
        '$write_eq'(ThreadedGoals, NewVarList, 0),
        '$read_input'(ThreadedGoals, NewVarList)
-    ;  C == p ->
+    ;  C = p ->
        nl,
        write('   '),
        '$write_eq'(ThreadedGoals, NewVarList, 20),
        '$read_input'(ThreadedGoals, NewVarList)
-    ;  C == (';') ->
+    ;  member(C, [';', ' ']) ->
        nl, write(';  '), false
-    ;  C == (' ') ->
-       nl, write(';  '), false
-    ;  C == h ->
+    ;  C = h ->
        '$help_message',
        '$read_input'(ThreadedGoals, NewVarList)
-    ;  C == '.' ->
+    ;  C = '.' ->
        nl, write(';  ...'), nl
     ; '$read_input'(ThreadedGoals, NewVarList)
     ).

From 98a32790cd5991b3c438511178b5c34225e010ba Mon Sep 17 00:00:00 2001
From: Markus Triska <triska@metalevel.at>
Date: Sat, 18 Apr 2020 17:47:24 +0200
Subject: [PATCH 2/3] ENHANCED: the toplevel interaction now supports RETURN as
 a synonym for "."

This is made possible due to the recent improvements by @notoria.
---
 README.md              | 4 ++--
 src/prolog/toplevel.pl | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 4fa1bab5..652e7b98 100644
--- a/README.md
+++ b/README.md
@@ -168,8 +168,8 @@ predicates it defines. For example, with the program shown above:
 ;  What = pure_world.
 ```
 
-Press `SPACE` to show further answers, if any exist. Press&nbsp;`.` to
-abort the search and return to the toplevel&nbsp;prompt.
+Press `SPACE` to show further answers, if any exist. Press `RETURN` or
+&nbsp;`.` to abort the search and return to the toplevel&nbsp;prompt.
 Press&nbsp;`h` to show a help message.
 
 To quit Scryer Prolog, use the standard predicate `halt/0`:
diff --git a/src/prolog/toplevel.pl b/src/prolog/toplevel.pl
index 09131d6d..6cee5ecc 100644
--- a/src/prolog/toplevel.pl
+++ b/src/prolog/toplevel.pl
@@ -161,7 +161,7 @@
     ;  C = h ->
        '$help_message',
        '$read_input'(ThreadedGoals, NewVarList)
-    ;  C = '.' ->
+    ;  member(C, ['\n', .]) ->
        nl, write(';  ...'), nl
     ; '$read_input'(ThreadedGoals, NewVarList)
     ).
@@ -169,7 +169,7 @@
 '$help_message' :-
     nl, nl,
     write('SPACE, "n" or ";": next solution, if any\n'),
-    write('".": stop enumeration\n'),
+    write('RETURN or ".": stop enumeration\n'),
     write('"h": display this help message\n'),
     write('"w": write terms without depth limit\n'),
     write('"p": print terms with depth limit\n\n').

From 2ae5472872b11110f014670edd548839c2f12da5 Mon Sep 17 00:00:00 2001
From: Markus Triska <triska@metalevel.at>
Date: Sat, 18 Apr 2020 18:08:08 +0200
Subject: [PATCH 3/3] reintroduce "n" as a synonym for ";" and " "

---
 src/prolog/toplevel.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/prolog/toplevel.pl b/src/prolog/toplevel.pl
index 6cee5ecc..aad24573 100644
--- a/src/prolog/toplevel.pl
+++ b/src/prolog/toplevel.pl
@@ -156,7 +156,7 @@
        write('   '),
        '$write_eq'(ThreadedGoals, NewVarList, 20),
        '$read_input'(ThreadedGoals, NewVarList)
-    ;  member(C, [';', ' ']) ->
+    ;  member(C, [';', ' ', n]) ->
        nl, write(';  '), false
     ;  C = h ->
        '$help_message',