Add IN generator

[dbsrgits/SQL-Abstract-2.0-ish.git] / lib / SQL / Abstract.pm

diff --git a/lib/SQL/Abstract.pm b/lib/SQL/Abstract.pm
index c5eafff..5026129 100644 (file)
--- a/lib/SQL/Abstract.pm
+++ b/lib/SQL/Abstract.pm
@@ -8,8 +8,11 @@ class SQL::Abstract {
   use Data::Dump qw/pp/;
 
   use Moose::Util::TypeConstraints;
-  use MooseX::Types -declare => ['NameSeparator'];
+  use MooseX::Types -declare => [qw/NameSeparator/];
   use MooseX::Types::Moose qw/ArrayRef Str/;
+  use MooseX::AttributeHelpers;
+
+  use namespace::clean -except => ['meta'];
 
   subtype NameSeparator,
     as ArrayRef[Str];
@@ -22,6 +25,19 @@ class SQL::Abstract {
 
   our $AST_VERSION = '1';
 
+  # Operator precedence for bracketing
+  our %PRIO = (
+    and => 10,
+    or  => 50
+  );
+
+  our %OP_MAP = (
+    '>' => '>',
+    '<' => '<',
+    '==' => '=',
+    '!=' => '!=',
+  );
+
   has name_separator => ( 
     is => 'rw', 
     isa => NameSeparator,
@@ -37,15 +53,57 @@ class SQL::Abstract {
     required => 1,
   );
 
-  method generate (ArrayRef $ast) {
-    $self = new $self unless blessed($self);
+  has binds => (
+    isa => ArrayRef,
+    is => 'ro',
+    default => sub { [ ] },
+    metaclass => 'Collection::Array',
+    provides => {
+      push => 'add_bind',
+      clear => '_clear_binds',
+    }
+  );
+
+  method generate (Object|ClassName $self: ArrayRef $ast) {
+    my $class_meth = !blessed($self);
+    $self = $self->new if $class_meth;
 
     local $_ = $ast->[0];
-    s/^-/_/ or croak "Unknown type tag '$_'";
-    return $self->$_($ast);
+    s/^-/_/g or croak "Unknown type tag '$_'";
+    my $meth = $self->can($_) || \&_generic_func;
+    return $class_meth
+         ? ($meth->($self, $ast), $self->binds)
+         : $meth->($self, $ast);
+  }
+
+  method _select(ArrayRef $ast) {
+    
+  }
+
+  method _where(ArrayRef $ast) {
+    my (undef, @clauses) = @$ast;
+  
+    return 'WHERE ' . $self->_recurse_where(\@clauses);
   }
 
-  method _name(ArrayRef[Str] $ast) {
+  method _order_by(ArrayRef $ast) {
+    my (undef, @clauses) = @$ast;
+
+    my @output;
+   
+    for (@clauses) {
+      if ($_->[0] =~ /^-(asc|desc)$/) {
+        my $o = $1;
+        push @output, $self->generate($_->[1]) . " " . uc($o);
+        next;
+      }
+      push @output, $self->generate($_);
+    }
+
+    return "ORDER BY " . join(", ", @output);
+  }
+
+  method _name(ArrayRef $ast) {
     my (undef, @names) = @$ast;
 
     my $sep = $self->name_separator;
@@ -64,7 +122,78 @@ class SQL::Abstract {
     return join(
       $self->list_separator,
       map { $self->generate($_) } @items);
-    
   }
 
+  method _alias(ArrayRef $ast) {
+    my (undef, $alias, $as) = @$ast;
+
+    return $self->generate($alias) . " AS $as";
+
+  }
+
+  method _value(ArrayRef $ast) {
+    my ($undef, $value) = @$ast;
+
+    $self->add_bind($value);
+    return "?";
+  }
+
+  method _recurse_where($clauses) {
+
+    my $OP = 'AND';
+    my $prio = $PRIO{and};
+    my $first = $clauses->[0];
+
+    if (!ref $first && $first =~ /^-(and|or)$/) {
+      $OP = uc($1);
+      $prio = $PRIO{$1};
+      shift @$clauses;
+    }
+
+    my @output;
+    foreach (@$clauses) {
+      croak "invalid component in where clause" unless ArrayRef->check($_);
+      my $op = $_->[0];
+
+      unless (substr($op, 0, 1) eq '-') {
+        # A simple comparison op (==, >, etc.)
+        
+        push @output, $self->_binop(@$_);
+        
+      } elsif ($op =~ /^-(and|or)$/) {
+        my $sub_prio = $PRIO{$1}; 
+
+        if ($sub_prio <= $prio) {
+          push @output, $self->_recurse_where($_);
+        } else {
+          push @output, '(' . $self->_recurse_where($_) . ')';
+        }
+      } else {
+        push @output, $self->generate($_);
+      }
+    }
+
+    return join(" $OP ", @output);
+  }
+
+  method _binop($op, $lhs, $rhs) {
+    join (' ', $self->generate($lhs), 
+               $OP_MAP{$op} || croak("Unknown binary operator $op"),
+               $self->generate($rhs)
+    );
+  }
+
+  method _in($ast) {
+    my (undef, $field, @values) = @$ast;
+
+    return $self->generate($field) .
+           " IN (" .
+           join(", ", map { $self->generate($_) } @values ) .
+           ")";
+  }
+
+  method _generic_func(ArrayRef $ast) {
+  }
+
+
 };