my @expression_start_keywords = (
'SELECT',
'UPDATE',
+ 'SET',
'INSERT \s+ INTO',
'DELETE \s+ FROM',
'FROM',
- 'SET',
'(?:
(?:
(?: (?: LEFT | RIGHT | FULL ) \s+ )?
'ON',
'WHERE',
'(?: DEFAULT \s+ )? VALUES',
- 'EXISTS',
+ '(?: NOT \s+)? EXISTS',
'GROUP \s+ BY',
'HAVING',
'ORDER \s+ BY',
# * BETWEEN without paranthesis around the ANDed arguments (which
# makes it a non-binary op) is detected and accomodated in
# _recurse_parse()
+# * AS is not really an operator but is handled here as it's also LHS/RHS
# this will be included in the $binary_op_re, the distinction is interesting during
# testing as one is tighter than the other, plus mathops have different look
my $binary_op_re = '(?: NOT \s+)? (?:' . join ('|', qw/IN BETWEEN R?LIKE/) . ')';
$binary_op_re = join "\n\t|\n",
- "$op_look_behind (?i: $binary_op_re ) $op_look_ahead",
+ "$op_look_behind (?i: $binary_op_re | AS ) $op_look_ahead",
$math_re,
$op_look_behind . 'IS (?:\s+ NOT)?' . "(?= \\s+ NULL \\b | $op_look_ahead )",
;
my $all_known_re = join("\n\t|\n",
$expr_start_re,
$binary_op_re,
- "$op_look_behind (?i: AND|OR|NOT ) $op_look_ahead",
- (map { quotemeta $_ } qw/, ( ) */),
+ "$op_look_behind (?i: AND|OR|NOT|\\* ) $op_look_ahead",
+ (map { quotemeta $_ } qw/, ( )/),
$placeholder_re,
);
my $magenta = [$c->('magenta'), $c->('reset')];
my $b_o_w = [$c->('black on_white'), $c->('reset')];
(
- placeholder_surround => [q(') . $c->('black on_magenta'), $c->('reset') . q(')],
+ placeholder_surround => [$c->('black on_magenta'), $c->('reset')],
colormap => {
'begin work' => $b_o_w,
commit => $b_o_w,
$self->_recurse_parse($tokens, PARSE_TOP_LEVEL);
}
+{
+# this is temporary, lists can be parsed *without* recursing, but
+# it requires a massive rewrite of the AST generator
+no warnings qw/recursion/;
sub _recurse_parse {
my ($self, $tokens, $state) = @_;
elsif ($token =~ /^ (?: OR | AND | \, ) $/xi ) {
my $op = ($token eq ',') ? 'LIST' : uc $token;
- my $right = $self->_recurse_parse($tokens, PARSE_IN_EXPR);
+ my $right = $self->_recurse_parse($tokens, PARSE_IN_EXPR) || [];
# Merge chunks if logic matches
- if (ref $right and $op eq $right->[0]) {
- $left = [ (shift @$right ), [$left||(), map { @$_ } @$right] ];
+ if (ref $right and @$right and $op eq $right->[0]) {
+ $left = [ (shift @$right ), [$left||[], map { @$_ } @$right] ];
}
else {
- $left = [$op => [ $left||(), $right||() ]];
+ $left = [$op => [ $left||[], $right ]];
}
}
# binary operator keywords
elsif ( $token =~ /^ NOT $/ix ) {
my $op = uc $token;
my $right = $self->_recurse_parse ($tokens, PARSE_RHS);
- $left = $left ? [ @$left, [$op => [$right] ]]
- : [ $op => [$right] ];
+ $left = $left ? [ @$left, [$op => [$right||()] ]]
+ : [ $op => [$right||()] ];
}
elsif ( $token =~ $placeholder_re) {
}
}
}
+}
sub format_keyword {
my ($self, $keyword) = @_;
if ($self->fill_in_placeholders) {
my $val = shift @{$bindargs} || '';
+ my $quoted = $val =~ s/^(['"])(.*)\1$/$2/;
my ($left, $right) = @{$self->placeholder_surround};
$val =~ s/\\/\\\\/g;
$val =~ s/'/\\'/g;
+ $val = qq('$val') if $quoted;
return qq($left$val$right)
}
return '?'
return '';
}
+ $self->_parenthesis_unroll($tree);
my ($car, $cdr) = @{$tree}[0,1];
if (! defined $car or (! ref $car and ! defined $cdr) ) {
return $self->fill_in_placeholder($bindargs);
}
elsif ($car eq 'PAREN') {
- return sprintf ('(%s)',
+ return sprintf ('( %s )',
join (' ', map { $self->_unparse($_, $bindargs, $depth + 2) } @{$cdr} )
.
($self->_is_key($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%s$r",
+ $self->format_keyword($car),
+ ( ref $cdr eq 'ARRAY' and ref $cdr->[0] eq 'ARRAY' and $cdr->[0][0] and $cdr->[0][0] eq 'PAREN' )
+ ? '' # mysql--
+ : ' '
+ ,
+ $self->_unparse($cdr, $bindargs, $depth),
+ ;
}
}
+# All of these keywords allow their parameters to be specified with or without parenthesis without changing the semantics
+my @unrollable_ops = (
+ 'ON',
+ 'WHERE',
+ 'GROUP \s+ BY',
+ 'HAVING',
+ 'ORDER \s+ BY',
+ 'I?LIKE',
+);
+my $unrollable_ops_re = join ' | ', @unrollable_ops;
+$unrollable_ops_re = qr/$unrollable_ops_re/xi;
+
+sub _parenthesis_unroll {
+ my $self = shift;
+ my $ast = shift;
+
+ #return if $self->parenthesis_significant;
+ return unless (ref $ast and ref $ast->[1]);
+
+ my $changes;
+ do {
+ my @children;
+ $changes = 0;
+
+ for my $child (@{$ast->[1]}) {
+ # the current node in this loop is *always* a PAREN
+ if (! ref $child or ! @$child or $child->[0] ne 'PAREN') {
+ push @children, $child;
+ next;
+ }
+
+ # unroll nested parenthesis
+ while ( @{$child->[1]} && $child->[1][0][0] eq 'PAREN') {
+ $child = $child->[1][0];
+ $changes++;
+ }
+
+ # if the parenthesis are wrapped around an AND/OR matching the parent AND/OR - open the parenthesis up and merge the list
+ if (
+ ( $ast->[0] eq 'AND' or $ast->[0] eq 'OR')
+ and
+ $child->[1][0][0] eq $ast->[0]
+ ) {
+ push @children, @{$child->[1][0][1]};
+ $changes++;
+ }
+
+ # if the parent operator explcitly allows it nuke the parenthesis
+ elsif ( $ast->[0] =~ $unrollable_ops_re ) {
+ push @children, $child->[1][0];
+ $changes++;
+ }
+
+ # only *ONE* LITERAL or placeholder element
+ # as an AND/OR/NOT argument
+ elsif (
+ @{$child->[1]} == 1 && (
+ $child->[1][0][0] eq 'LITERAL'
+ or
+ $child->[1][0][0] eq 'PLACEHOLDER'
+ ) && (
+ $ast->[0] eq 'AND' or $ast->[0] eq 'OR' or $ast->[0] eq 'NOT'
+ )
+ ) {
+ push @children, $child->[1][0];
+ $changes++;
+ }
+
+ # only one element in the parenthesis which is a binary op
+ # and has exactly two grandchildren
+ # the only time when we can *not* unroll this is when both
+ # the parent and the child are mathops (in which case we'll
+ # break precedence) or when the child is BETWEEN (special
+ # case)
+ elsif (
+ @{$child->[1]} == 1
+ and
+ $child->[1][0][0] =~ SQL::Abstract::Tree::_binary_op_re()
+ and
+ $child->[1][0][0] ne 'BETWEEN'
+ and
+ @{$child->[1][0][1]} == 2
+ and
+ ! (
+ $child->[1][0][0] =~ SQL::Abstract::Tree::_math_op_re()
+ and
+ $ast->[0] =~ SQL::Abstract::Tree::_math_op_re()
+ )
+ ) {
+ push @children, $child->[1][0];
+ $changes++;
+ }
+
+ # a function binds tighter than a mathop - see if our ancestor is a
+ # mathop, and our content is:
+ # a single non-mathop child with a single PAREN grandchild which
+ # would indicate mathop ( nonmathop ( ... ) )
+ # or a single non-mathop with a single LITERAL ( nonmathop foo )
+ # or a single non-mathop with a single PLACEHOLDER ( nonmathop ? )
+ elsif (
+ @{$child->[1]} == 1
+ and
+ @{$child->[1][0][1]} == 1
+ and
+ $ast->[0] =~ SQL::Abstract::Tree::_math_op_re()
+ and
+ $child->[1][0][0] !~ SQL::Abstract::Tree::_math_op_re
+ and
+ (
+ $child->[1][0][1][0][0] eq 'PAREN'
+ or
+ $child->[1][0][1][0][0] eq 'LITERAL'
+ or
+ $child->[1][0][1][0][0] eq 'PLACEHOLDER'
+ )
+ ) {
+ push @children, $child->[1][0];
+ $changes++;
+ }
+
+
+ # otherwise no more mucking for this pass
+ else {
+ push @children, $child;
+ }
+ }
+
+ $ast->[1] = \@children;
+
+ } while ($changes);
+
+}
+
sub format { my $self = shift; $self->unparse($self->parse($_[0]), $_[1]) }
1;
=pod
+=head1 NAME
+
+SQL::Abstract::Tree - Represent SQL as an AST
+
=head1 SYNOPSIS
my $sqla_tree = SQL::Abstract::Tree->new({ profile => 'console' });
projects / dbsrgits/SQL-Abstract.git / blobdiff