allow deep data structure interpolation in ysql

'$.foo.bar' now gets the right thing out of a hash of hashes.

Fixes #70

bin/ysql

@@ -65,11 +65,17 @@ named placeholders, which begin with C<$.>. For example:
     ---
     name: Stormy Waters
     email: stormy@example.com
+    profile:
+        dept: Pilot
     ---
     name: Debbie Dupree
     email: debbie@example.com
+    profile:
+        dept: Wildlife
 
-    $ ysql write 'INSERT INTO person ( name, email ) VALUES ( $.name, $.email )' <input.yml
+    $ ysql write 'INSERT INTO person ( name, email, dept ) \
+                  VALUES ( $.name, $.email, $.profile.dept )' \
+                  < input.yml
 
 =head1 ARGUMENTS
 

lib/ETL/Yertl/Command/ysql.pm

@@ -32,19 +32,29 @@ sub main {
     elsif ( $command eq 'write' ) {
         my $query = shift;
 
-        my @fields = $query =~ m/\$\.(\w+)/g;
-        $query =~ s/\$\.\w+/?/g;
+        my @fields = $query =~ m/\$(\.[.\w]+)/g;
+        $query =~ s/\$\.[\w.]+/?/g;
 
         my $dbh = DBI->connect( $opt{dsn} );
         my $sth = $dbh->prepare( $query );
 
         my $in_fmt = ETL::Yertl::Format::yaml->new( input => \*STDIN );
         for my $doc ( $in_fmt->read ) {
-            $sth->execute( map { $doc->{ $_ } } @fields );
+            $sth->execute( map { select_doc( $_, $doc ) } @fields );
         }
     }
 }
 
+sub select_doc {
+    my ( $select, $doc ) = @_;
+    $select =~ s/^[.]//; # select must start with .
+    my @parts = split /[.]/, $select;
+    for my $part ( @parts ) {
+        $doc = $doc->{ $part };
+    }
+    return $doc;
+}
+
 1;
 __END__
 

t/bin/ysql.t

@@ -77,6 +77,32 @@ subtest 'write' => sub {
             );
     };
 
+    subtest 'interpolation' => sub {
+
+        subtest 'deep data structure' => sub {
+            my $tmp = tempfile;
+            my $dbi = DBI->connect( 'dbi:SQLite:dbname=' . $tmp );
+            $dbi->do( 'CREATE TABLE person ( id INT, name VARCHAR, email VARCHAR )' );
+            local *STDIN = $SHARE_DIR->child( 'command', 'ysql', 'deep.yml' )->openr;
+
+            my ( $stdout, $stderr, $exit ) = capture {
+                ysql->main( '--dsn', 'dbi:SQLite:dbname=' . $tmp, 'write',
+                    'INSERT INTO person (id, name, email) VALUES ($.id, $.profile.name, $.email)',
+                );
+            };
+            is $exit, 0;
+            ok !$stderr, 'nothing on stderr' or diag $stderr;
+            ok !$stdout, 'nothing on stdout' or diag $stdout;
+
+            cmp_deeply
+                $dbi->selectall_arrayref( 'SELECT id,name,email FROM person' ),
+                bag(
+                    [ 1, 'Hazel Murphy', 'hank@example.com' ],
+                    [ 2, 'Quentin Quinn', 'quinn@example.com' ],
+                );
+        };
+    };
+
 };
 
 

t/share/command/ysql/deep.yml

@@ -0,0 +1,10 @@
+---
+id: 1
+profile:
+    name: Hazel Murphy
+email: hank@example.com
+---
+id: 2
+profile:
+    name: Quentin Quinn
+email: quinn@example.com