From 71d2179ea2c1d4ecd9c0b76e043e58caa8117579 Mon Sep 17 00:00:00 2001
From: Juerd Waalboer <juerd@tnx.nl>
Date: Thu, 28 Dec 2023 20:36:57 +0100
Subject: [PATCH] Better cursor position after input syntax error

---
 lib/RevBank/Prompt.pm | 14 +++++++++-----
 revbank               | 12 +++++++-----
 t/prompt.t            | 19 +++++++++++++------
 3 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/lib/RevBank/Prompt.pm b/lib/RevBank/Prompt.pm
index 890173d..d91547c 100755
--- a/lib/RevBank/Prompt.pm
+++ b/lib/RevBank/Prompt.pm
@@ -21,13 +21,16 @@ sub split_input($input) {
 
     my @terms;
     my $pos = 0;
+    my $lastpos = 0;
+
+    my sub _P($nudge = 0) { $pos = pos($input) + $nudge; }
 
     while (
         $input =~ m[
             \G \s*+
-            (?| (') ( (?: \\. | [^\\']  )*+ ) '   (?=\s|;|$)
-              | (") ( (?: \\. | [^\\"]  )*+ ) "   (?=\s|;|$)
-              | ()  ( (?: \\. | [^\\;'"\s] )++ )  (?=\s|;|$)
+            (?| (') (?{_P -1}) ( (?: \\. | [^\\']  )*+ ) ' (?{_P}) (?=\s|;|$)
+              | (") (?{_P -1}) ( (?: \\. | [^\\"]  )*+ ) " (?{_P}) (?=\s|;|$)
+              | ()  ( (?: \\. | [^\\;'"\s] )++ )           (?{_P}) (?=\s|;|$)
               | ()  (;)
             )
         ]xg
@@ -38,11 +41,12 @@ sub split_input($input) {
             : $1 && $2 eq "abort" ? "abort"
             : $2
         );
-        $pos = pos($input) || 0;
+        $lastpos = pos($input) || 0;
+        $pos ||= $lastpos;
     }
 
     # End of string not reached
-    return \$pos if $pos < length($input);
+    return \$pos if $lastpos < length($input);
 
     # End of string reached
     s[\\(.)]{ $escapes{$1} // $1 }ge for @terms;
diff --git a/revbank b/revbank
index b1cface..b991557 100755
--- a/revbank
+++ b/revbank
@@ -18,7 +18,7 @@ use RevBank::Messages;
 use RevBank::Cart;
 use RevBank::Prompt;
 
-our $VERSION = "5.1.0";
+our $VERSION = "5.1.1";
 our %HELP1 = (
     "abort" => "Abort the current transaction",
 );
@@ -101,10 +101,9 @@ OUTER: for (;;) {
                     }
                 }
 
-                $default = $word_based
-                    ? join(" ", @accepted, @rejected, @trailing)
-                    : join("", @accepted, @rejected);
-                $pos = @accepted ? 1 + length "@accepted" : 0;
+                my $sep = $word_based ? " " : "";
+                $default = join($sep, @accepted, @rejected, @trailing);
+                $pos = @accepted ? length "@accepted$sep" : 0;
 
                 @retry = ();
                 $retry = 0;
@@ -122,14 +121,17 @@ OUTER: for (;;) {
                 @words = RevBank::Prompt::split_input($input);
                 if (ref $words[0]) {
                     my $pos = ${ $words[0] };
+
                     @retry = @words = ();
                     $retry = "Syntax error.";
+
                     if ($input =~ /['"]/) {
                         $retry .= " (Quotes must match and (only) be at both ends of a term.)";
                         if (($input =~ tr/'//) == 1 and $input !~ /"/) {
                             $retry .= "\nDid you mean: " . $input =~ s/'/\\'/r;
                         }
                     }
+
                     push @retry, substr($input, 0, $pos) if $pos > 0;
                     push @retry, substr($input, $pos);
                     redo PROMPT;
diff --git a/t/prompt.t b/t/prompt.t
index 345b0c2..19b3034 100644
--- a/t/prompt.t
+++ b/t/prompt.t
@@ -72,13 +72,20 @@ are '"abort"', [qw/abort/];
 
 are "\\", 0;
 are "'foo", 0;
-are "foo'", 0;
-are "foo'bar", 0;
 
-are "bar 'foo", 3;
-are "bar foo'", 3;
-are "bar foo'bar", 3;
+#    0123
+are "foo'", 3;
+#    0123
+are "foo'bar", 3;
 
-are "foo 'bar'\"baz\"", 3;
+#    01234
+are "bar 'foo", 4;
+#    01234567
+are "bar foo'", 7;
+#    01234567
+are "bar foo'bar", 7;
+
+#    0123456789
+are "foo 'bar'\"baz\"", 9;
 
 done_testing;