'HAVING',
'ORDER \s+ BY',
'SKIP',
+ 'FETCH',
'FIRST',
'LIMIT',
'OFFSET',
# These are binary operator keywords always a single LHS and RHS
# * AND/OR are handled separately as they are N-ary
# * so is NOT as being unary
-# * BETWEEN without paranthesis around the ANDed arguments (which
-# makes it a non-binary op) is detected and accomodated in
+# * BETWEEN without parentheses around the ANDed arguments (which
+# makes it a non-binary op) is detected and accommodated 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
-# ahead/behind (e.g. "x"="y" )
-my @math_op_keywords = (qw/ < > != <> = <= >= /);
-my $math_op_re = join ("\n\t|\n", map
+# testing as one is tighter than the other, plus alphanum cmp ops have different
+# look ahead/behind (e.g. "x"="y" )
+my @alphanum_cmp_op_keywords = (qw/< > != <> = <= >= /);
+my $alphanum_cmp_op_re = join ("\n\t|\n", map
{ "(?: (?<= [\\w\\s] | $quote_right ) | \\A )" . quotemeta ($_) . "(?: (?= [\\w\\s] | $quote_left ) | \\z )" }
- @math_op_keywords
+ @alphanum_cmp_op_keywords
);
-$math_op_re = qr/$math_op_re/x;
+$alphanum_cmp_op_re = qr/$alphanum_cmp_op_re/x;
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 | AS ) $op_look_ahead",
- $math_op_re,
+ $alphanum_cmp_op_re,
$op_look_behind . 'IS (?:\s+ NOT)?' . "(?= \\s+ NULL \\b | $op_look_ahead )",
;
$binary_op_re = qr/$binary_op_re/x;
$unary_op_re,
$asc_desc_re,
$and_or_re,
- "$op_look_behind \\* $op_look_ahead",
+ $op_look_behind . ' \* ' . $op_look_ahead,
(map { quotemeta $_ } qw/, ( )/),
$placeholder_re,
);
# this one *is* capturing for the split below
# splits on whitespace if all else fails
-# has to happen before the composiign qr's are anchored (below)
+# has to happen before the composing qr's are anchored (below)
$tokenizer_re = qr/ \s* ( $tokenizer_re ) \s* | \s+ /x;
# Parser states for _recurse_parse()
my $expr_term_re = qr/$expr_start_re | \)/x;
my $rhs_term_re = qr/ $expr_term_re | $binary_op_re | $unary_op_re | $asc_desc_re | $and_or_re | \, /x;
-my $common_single_args_re = qr/ \* | $placeholder_re /x;
-my $all_std_keywords_re = qr/ $rhs_term_re | \( | $common_single_args_re /x;
+my $all_std_keywords_re = qr/ $rhs_term_re | \( | $placeholder_re /x;
# anchor everything - even though keywords are separated by the tokenizer, leakage may occur
for (
$quote_right,
$placeholder_re,
$expr_start_re,
- $math_op_re,
+ $alphanum_cmp_op_re,
$binary_op_re,
$unary_op_re,
$asc_desc_re,
$and_or_re,
$expr_term_re,
$rhs_term_re,
- $common_single_args_re,
$all_std_keywords_re,
) {
$_ = qr/ \A $_ \z /x;
}
-
+# what can be bunched together under one MISC in an AST
+my $compressable_node_re = qr/^ \- (?: MISC | LITERAL | PLACEHOLDER ) $/x;
my %indents = (
select => 0,
@right = $self->_recurse_parse($tokens, PARSE_IN_EXPR);
}
- @left = [$op => [ @left, @right ]];
+ push @left, [$op => [ (@left ? pop @left : ''), @right ]];
}
# unary op keywords
}
# check if the current token is an unknown op-start
- elsif (@$tokens and ($tokens->[0] eq '(' or $tokens->[0] =~ $common_single_args_re ) ) {
+ elsif (@$tokens and ($tokens->[0] eq '(' or $tokens->[0] =~ $placeholder_re ) ) {
push @left, [ $token => [ $self->_recurse_parse($tokens, PARSE_RHS) ] ];
}
# we're now in "unknown token" land - start eating tokens until
- # we see something familiar
+ # we see something familiar, OR in the case of RHS (binop) stop
+ # after the first token
+ # Also stop processing when we could end up with an unknown func
else {
my @lits = [ -LITERAL => [$token] ];
- while (@$tokens and $tokens->[0] !~ $all_std_keywords_re) {
- push @lits, [ -LITERAL => [ shift @$tokens ] ];
- }
+ unshift @lits, pop @left if @left == 1;
- if (@left == 1) {
- unshift @lits, pop @left;
- }
+ unless ( $state == PARSE_RHS ) {
+ while (
+ @$tokens
+ and
+ $tokens->[0] !~ $all_std_keywords_re
+ and
+ ! ( @$tokens > 1 and $tokens->[1] eq '(' )
+ ) {
+ push @lits, [ -LITERAL => [ shift @$tokens ] ];
+ }
+ }
@lits = [ -MISC => [ @lits ] ] if @lits > 1;
push @left, @lits;
}
- # deal with post-fix operators (only when sql is sane - i.e. we have one element to apply to)
- if (@left == 1 and @$tokens) {
-
- # asc/desc
- if ($tokens->[0] =~ $asc_desc_re) {
- my $op = shift @$tokens;
-
- # if -MISC - this is a literal collection, do not promote asc/desc to an op
- if ($left[0][0] eq '-MISC') {
- push @{$left[0][1]}, [ -LITERAL => [ $op ] ];
+ # compress -LITERAL -MISC and -PLACEHOLDER pieces into a single
+ # -MISC container
+ if (@left > 1) {
+ my $i = 0;
+ while ($#left > $i) {
+ if ($left[$i][0] =~ $compressable_node_re and $left[$i+1][0] =~ $compressable_node_re) {
+ splice @left, $i, 2, [ -MISC => [
+ map { $_->[0] eq '-MISC' ? @{$_->[1]} : $_ } (@left[$i, $i+1])
+ ]];
}
else {
- @left = [ ('-' . uc ($op)) => [ @left ] ];
+ $i++;
}
}
}
+
+ return @left if $state == PARSE_RHS;
+
+ # deal with post-fix operators
+ if (@$tokens) {
+ # asc/desc
+ if ($tokens->[0] =~ $asc_desc_re) {
+ @left = [ ('-' . uc (shift @$tokens)) => [ @left ] ];
+ }
+ }
}
}
elsif ($op eq '-MISC' ) {
return join (' ', map $self->_unparse($_, $bindargs, $depth), @{$args});
}
+ elsif ($op =~ qr/^-(ASC|DESC)$/ ) {
+ my $dir = $1;
+ return join (' ', (map $self->_unparse($_, $bindargs, $depth), @{$args}), $dir);
+ }
else {
my ($l, $r) = @{$self->pad_keyword($op, $depth)};
- return sprintf "$l%s%s%s$r",
- $self->format_keyword($op),
+
+ my $rhs = $self->_unparse($args, $bindargs, $depth);
+
+ return sprintf "$l%s$r", join(
( ref $args eq 'ARRAY' and @{$args} == 1 and $args->[0][0] eq '-PAREN' )
? '' # mysql--
: ' '
,
- $self->_unparse($args, $bindargs, $depth),
- ;
+ $self->format_keyword($op),
+ (length $rhs ? $rhs : () ),
+ );
}
}
}
# unroll nested parenthesis
- while ( @{$child->[1]} == 1 and $child->[1][0][0] eq '-PAREN') {
+ while ( $ast->[0] ne 'IN' and @{$child->[1]} == 1 and $child->[1][0][0] eq '-PAREN') {
$child = $child->[1][0];
$changes++;
}
- # if the parent operator explcitly allows it nuke the parenthesis
+ # if the parent operator explicitly allows it nuke the parenthesis
if ( $ast->[0] =~ $unrollable_ops_re ) {
push @children, @{$child->[1]};
$changes++;
@{$child->[1][0][1]} == 2
and
! (
- $child->[1][0][0] =~ $math_op_re
+ $child->[1][0][0] =~ $alphanum_cmp_op_re
and
- $ast->[0] =~ $math_op_re
+ $ast->[0] =~ $alphanum_cmp_op_re
)
) {
push @children, @{$child->[1]};
and
@{$child->[1][0][1]} == 1
and
- $ast->[0] =~ $math_op_re
+ $ast->[0] =~ $alphanum_cmp_op_re
and
- $child->[1][0][0] !~ $math_op_re
+ $child->[1][0][0] !~ $alphanum_cmp_op_re
and
(
$child->[1][0][1][0][0] eq '-PAREN'
$changes++;
}
+ # a construct of ... ( somefunc ( ... ) ) ... can safely lose the outer parens
+ # except for the case of ( NOT ( ... ) ) which has already been handled earlier
+ elsif (
+ @{$child->[1]} == 1
+ and
+ @{$child->[1][0][1]} == 1
+ and
+ $child->[1][0][0] ne 'NOT'
+ and
+ ref $child->[1][0][1][0] eq 'ARRAY'
+ and
+ $child->[1][0][1][0][0] eq '-PAREN'
+ ) {
+ push @children, @{$child->[1]};
+ $changes++;
+ }
+
# otherwise no more mucking for this pass
else {
} while ($changes);
}
+sub _strip_asc_from_order_by {
+ my ($self, $ast) = @_;
+
+ return $ast if (
+ ref $ast ne 'ARRAY'
+ or
+ $ast->[0] ne 'ORDER BY'
+ );
+
+
+ my $to_replace;
+
+ if (@{$ast->[1]} == 1 and $ast->[1][0][0] eq '-ASC') {
+ $to_replace = [ $ast->[1][0] ];
+ }
+ elsif (@{$ast->[1]} == 1 and $ast->[1][0][0] eq '-LIST') {
+ $to_replace = [ grep { $_->[0] eq '-ASC' } @{$ast->[1][0][1]} ];
+ }
+
+ @$_ = @{$_->[1][0]} for @$to_replace;
+
+ $ast;
+}
+
sub format { my $self = shift; $self->unparse($self->parse($_[0]), $_[1]) }
1;
=head2 unparse
- $sqlat->parse($tree_structure, \@bindargs)
+ $sqlat->unparse($tree_structure, \@bindargs)
Transform "tree" into SQL, applying various transforms on the way.