Proper placeholder support in the AST

[dbsrgits/SQL-Abstract.git] / lib / SQL / Abstract / Tree.pm

diff --git a/lib/SQL/Abstract/Tree.pm b/lib/SQL/Abstract/Tree.pm
index 7b97b29..fd9f665 100644 (file)
--- a/lib/SQL/Abstract/Tree.pm
+++ b/lib/SQL/Abstract/Tree.pm
@@ -40,6 +40,8 @@ my $op_look_behind = '(?: (?<= [\,\s\)\(] ) | \A )';
 my $quote_left = qr/[\`\'\"\[]/;
 my $quote_right = qr/[\`\'\"\]]/;
 
+my $placeholder_re = qr/(?: \? | \$\d+ )/x;
+
 # These SQL keywords always signal end of the current expression (except inside
 # of a parenthesized subexpression).
 # Format: A list of strings that will be compiled to extended syntax ie.
@@ -114,6 +116,7 @@ my $all_known_re = join("\n\t|\n",
   $binary_op_re,
   "$op_look_behind (?i: AND|OR|NOT ) $op_look_ahead",
   (map { quotemeta $_ } qw/, ( ) */),
+  $placeholder_re,
 );
 
 $all_known_re = qr/$all_known_re/x;
@@ -131,7 +134,7 @@ use constant PARSE_RHS => 4;
 
 my $expr_term_re = qr/ ^ (?: $expr_start_re | \) ) $/x;
 my $rhs_term_re = qr/ ^ (?: $expr_term_re | $binary_op_re | (?i: AND | OR | NOT | \, ) ) $/x;
-my $func_start_re = qr/^ (?: \? | \$\d+ | \( ) $/x;
+my $func_start_re = qr/^ (?: \* | $placeholder_re | \( ) $/x;
 
 my %indents = (
    select        => 0,
@@ -326,6 +329,10 @@ sub _recurse_parse {
                     : [ $op => [$right] ];
 
     }
+    elsif ( $token =~ $placeholder_re) {
+      $left = $left ? [ $left, [ PLACEHOLDER => [ $token ] ] ]
+                    : [ PLACEHOLDER => [ $token ] ];
+    }
     # we're now in "unknown token" land - start eating tokens until
     # we see something familiar
     else {
@@ -395,10 +402,14 @@ sub fill_in_placeholder {
    return '?'
 }
 
+# FIXME - terrible name for a user facing API
 sub unparse {
-  my ($self, $tree, $bindargs, $depth) = @_;
+  my ($self, $tree, $bindargs) = @_;
+  $self->_unparse($tree, [@{$bindargs||[]}], 0);
+}
 
-  $depth ||= 0;
+sub _unparse {
+  my ($self, $tree, $bindargs, $depth) = @_;
 
   if (not $tree or not @$tree) {
     return '';
@@ -414,29 +425,29 @@ sub unparse {
   }
 
   if (ref $car) {
-    return join (' ', map $self->unparse($_, $bindargs, $depth), @$tree);
+    return join (' ', map $self->_unparse($_, $bindargs, $depth), @$tree);
   }
   elsif ($car eq 'LITERAL') {
-    if ($cdr->[0] eq '?') {
-      return $self->fill_in_placeholder($bindargs)
-    }
     return $cdr->[0];
   }
+  elsif ($car eq 'PLACEHOLDER') {
+    return $self->fill_in_placeholder($bindargs);
+  }
   elsif ($car eq 'PAREN') {
     return '(' .
       join(' ',
-        map $self->unparse($_, $bindargs, $depth + 2), @{$cdr}) .
+        map $self->_unparse($_, $bindargs, $depth + 2), @{$cdr}) .
     ($self->_is_key($cdr)?( $self->newline||'' ).$self->indent($depth + 1):'') . ') ';
   }
   elsif ($car eq 'AND' or $car eq 'OR' or $car =~ / ^ $binary_op_re $ /x ) {
-    return join (" $car ", map $self->unparse($_, $bindargs, $depth), @{$cdr});
+    return join (" $car ", map $self->_unparse($_, $bindargs, $depth), @{$cdr});
   }
   elsif ($car eq 'LIST' ) {
-    return join (', ', map $self->unparse($_, $bindargs, $depth), @{$cdr});
+    return join (', ', map $self->_unparse($_, $bindargs, $depth), @{$cdr});
   }
   else {
     my ($l, $r) = @{$self->pad_keyword($car, $depth)};
-    return sprintf "$l%s %s$r", $self->format_keyword($car), $self->unparse($cdr, $bindargs, $depth);
+    return sprintf "$l%s %s$r", $self->format_keyword($car), $self->_unparse($cdr, $bindargs, $depth);
   }
 }