Replaced explicit calls to Component::build() with implicit calls to Component::__toString().

Fixed bugs that caused field names like '0', '0.0', etc. to be considered invalid.
Refactoring.

25 files changed, 112 insertions, 134 deletions

diff --git a/src/Components/AlterOperation.php b/src/Components/AlterOperation.php
index c99d391..348f81f 100644
--- a/src/Components/AlterOperation.php
+++ b/src/Components/AlterOperation.php
@@ -202,7 +202,6 @@ class AlterOperation extends Component
                 __('Unrecognized alter operation.'),
                 $list->tokens[$list->idx]
             );
-            return null;
         }
 
         --$list->idx;
@@ -216,9 +215,9 @@ class AlterOperation extends Component
      */
     public static function build($component)
     {
-        $ret = OptionsArray::build($component->options) . ' ';
-        if (!empty($component->field)) {
-            $ret .= Expression::build($component->field) . ' ';
+        $ret = $component->options . ' ';
+        if ((isset($component->field)) && ($component->field !== '')) {
+            $ret .= $component->field . ' ';
         }
         $ret .= TokensList::build($component->unknown);
         return $ret;
diff --git a/src/Components/ArrayObj.php b/src/Components/ArrayObj.php
index 0e0b183..d3017fa 100644
--- a/src/Components/ArrayObj.php
+++ b/src/Components/ArrayObj.php
@@ -136,7 +136,6 @@ class ArrayObj extends Component
                     break;
                 }
             }
-
         }
 
         return $ret;
@@ -150,21 +149,11 @@ class ArrayObj extends Component
     public static function build($component)
     {
         if (is_array($component)) {
-            $values = array();
-            foreach ($component as $c) {
-                $values[] = static::build($c);
-            }
-            return implode(', ', $values);
+            return implode(', ', $component);
+        } elseif (!empty($component->raw)) {
+            return '(' . implode(', ', $component->raw) . ')';
         } else {
-            $values = array();
-            if (!empty($component->raw)) {
-                $values = $component->raw;
-            } else {
-                foreach ($component->values as $value) {
-                    $values[] = $value;
-                }
-            }
-            return '(' . implode(', ', $values) . ')';
+            return '(' . implode(', ', $component->values) . ')';
         }
     }
 }
diff --git a/src/Components/Condition.php b/src/Components/Condition.php
index 1f515dc..c8b4d1e 100644
--- a/src/Components/Condition.php
+++ b/src/Components/Condition.php
@@ -202,10 +202,10 @@ class Condition extends Component
      */
     public static function build($component)
     {
-        $ret = array();
-        foreach ($component as $c) {
-            $ret[] = $c->expr;
+        if (is_array($component)) {
+            return implode(' ', $component);
+        } else {
+            return $component->expr;
         }
-        return implode(' ', $ret);
     }
 }
diff --git a/src/Components/CreateDefinition.php b/src/Components/CreateDefinition.php
index 5671801..54c2475 100644
--- a/src/Components/CreateDefinition.php
+++ b/src/Components/CreateDefinition.php
@@ -278,11 +278,7 @@ class CreateDefinition extends Component
     public static function build($component)
     {
         if (is_array($component)) {
-            $ret = array();
-            foreach ($component as $c) {
-                $ret[] = static::build($c);
-            }
-            return "(\n" . implode(",\n", $ret) . "\n)";
+            return "(\n" . implode(",\n", $component) . "\n)";
         } else {
             $tmp = '';
 
@@ -290,23 +286,23 @@ class CreateDefinition extends Component
                 $tmp .= 'CONSTRAINT ';
             }
 
-            if (!empty($component->name)) {
+            if ((isset($component->name)) && ($component->name !== '')) {
                 $tmp .= Context::escape($component->name) . ' ';
             }
 
             if (!empty($component->type)) {
-                $tmp .= DataType::build($component->type) . ' ';
+                $tmp .= $component->type . ' ';
             }
 
             if (!empty($component->key)) {
-                $tmp .= Key::build($component->key) . ' ';
+                $tmp .= $component->key . ' ';
             }
 
             if (!empty($component->references)) {
-                $tmp .= 'REFERENCES ' . Reference::build($component->references) . ' ';
+                $tmp .= 'REFERENCES ' . $component->references . ' ';
             }
 
-            $tmp .= OptionsArray::build($component->options);
+            $tmp .= $component->options;
 
             return trim($tmp);
         }
diff --git a/src/Components/DataType.php b/src/Components/DataType.php
index 48ce5b7..8d42ea1 100644
--- a/src/Components/DataType.php
+++ b/src/Components/DataType.php
@@ -160,9 +160,7 @@ class DataType extends Component
         if (!empty($component->parameters)) {
             $tmp = '(' . implode(', ', $component->parameters) . ')';
         }
-        return trim(
-            $component->name . $tmp . ' '
-            . OptionsArray::build($component->options)
-        );
+
+        return trim($component->name . $tmp . ' ' . $component->options);
     }
 }
diff --git a/src/Components/Expression.php b/src/Components/Expression.php
index 11e7132..ad4d5e8 100644
--- a/src/Components/Expression.php
+++ b/src/Components/Expression.php
@@ -350,32 +350,36 @@ class Expression extends Component
     }
 
     /**
-     * @param Expression $component The component to be built.
+     * @param Expression|Expression[] $component The component to be built.
      *
      * @return string
      */
     public static function build($component)
     {
-        if (!empty($component->expr)) {
-            $ret = $component->expr;
+        if (is_array($component)) {
+            return implode($component, ', ');
         } else {
-            $fields = array();
-            if (!empty($component->database)) {
-                $fields[] = $component->database;
-            }
-            if (!empty($component->table)) {
-                $fields[] = $component->table;
+            if (!empty($component->expr)) {
+                $ret = $component->expr;
+            } else {
+                $fields = array();
+                if ((isset($component->database)) && ($component->database !== '')) {
+                    $fields[] = $component->database;
+                }
+                if ((isset($component->table)) && ($component->table !== '')) {
+                    $fields[] = $component->table;
+                }
+                if ((isset($component->column)) && ($component->column !== '')) {
+                    $fields[] = $component->column;
+                }
+                $ret = implode('.', Context::escape($fields));
             }
-            if (!empty($component->column)) {
-                $fields[] = $component->column;
+
+            if (!empty($component->alias)) {
+                $ret .= ' AS ' . Context::escape($component->alias);
             }
-            $ret = implode('.', Context::escape($fields));
-        }
 
-        if (!empty($component->alias)) {
-            $ret .= ' AS ' . Context::escape($component->alias);
+            return $ret;
         }
-
-        return $ret;
     }
 }
diff --git a/src/Components/FunctionCall.php b/src/Components/FunctionCall.php
index 43eb082..55d9e2c 100644
--- a/src/Components/FunctionCall.php
+++ b/src/Components/FunctionCall.php
@@ -120,6 +120,6 @@ class FunctionCall extends Component
      */
     public static function build($component)
     {
-        return $component->name . ArrayObj::build($component->parameters);
+        return $component->name . $component->parameters;
     }
 }
diff --git a/src/Components/IntoKeyword.php b/src/Components/IntoKeyword.php
index 5e4afcb..05540e6 100644
--- a/src/Components/IntoKeyword.php
+++ b/src/Components/IntoKeyword.php
@@ -141,7 +141,7 @@ class IntoKeyword extends Component
         if ($component->dest instanceof Expression) {
             $columns = !empty($component->columns) ?
                 '(' . implode(', ', $component->columns) . ')' : '';
-            return Expression::build($component->dest) . $columns;
+            return $component->dest . $columns;
         } else {
             return 'OUTFILE "' . $component->dest . '"';
         }
diff --git a/src/Components/JoinKeyword.php b/src/Components/JoinKeyword.php
index 237022a..b95912e 100644
--- a/src/Components/JoinKeyword.php
+++ b/src/Components/JoinKeyword.php
@@ -158,8 +158,8 @@ class JoinKeyword extends Component
     {
         $ret = array();
         foreach ($component as $c) {
-            $ret[] = (($c->type === 'JOIN') ? 'JOIN ' : ($c->type . ' JOIN ')) .
-                Expression::build($c->expr) . ' ON ' . Condition::build($c->on);
+            $ret[] = (($c->type === 'JOIN') ? 'JOIN ' : ($c->type . ' JOIN '))
+               . $c->expr . ' ON ' . Condition::build($c->on);
         }
         return implode(' ', $ret);
     }
diff --git a/src/Components/Key.php b/src/Components/Key.php
index 1364a8c..ef5d3a8 100644
--- a/src/Components/Key.php
+++ b/src/Components/Key.php
@@ -145,7 +145,6 @@ class Key extends Component
                 ++$list->idx;
                 break;
             }
-
         }
 
         --$list->idx;
@@ -163,8 +162,8 @@ class Key extends Component
         if (!empty($component->name)) {
             $ret .= Context::escape($component->name) . ' ';
         }
-        $ret .= '(' . implode(', ', Context::escape($component->columns)) . ')';
-        $ret .= OptionsArray::build($component->options);
+        $ret .= '(' . implode(', ', Context::escape($component->columns)) . ') '
+            . $component->options;
         return trim($ret);
     }
 }
diff --git a/src/Components/OptionsArray.php b/src/Components/OptionsArray.php
index 6b43844..a496273 100644
--- a/src/Components/OptionsArray.php
+++ b/src/Components/OptionsArray.php
@@ -256,9 +256,10 @@ class OptionsArray extends Component
      */
     public static function build($component)
     {
-        if ((empty($component)) || (!is_array($component->options))) {
+        if (empty($component->options)) {
             return '';
         }
+
         $options = array();
         foreach ($component->options as $option) {
             if (!is_array($option)) {
@@ -266,9 +267,7 @@ class OptionsArray extends Component
             } else {
                 $options[] = $option['name']
                     . (!empty($option['equals']) ? '=' : ' ')
-                    . (!empty($option['expr']) ? ((string) $option['expr']) : $option['value']);
-                // If `$option['expr']` happens to be a component, the magic
-                // method will build it automatically.
+                    . (!empty($option['expr']) ? $option['expr'] : $option['value']);
             }
         }
         return implode(' ', $options);
diff --git a/src/Components/OrderKeyword.php b/src/Components/OrderKeyword.php
index 81bff2f..b6918e9 100644
--- a/src/Components/OrderKeyword.php
+++ b/src/Components/OrderKeyword.php
@@ -126,20 +126,16 @@ class OrderKeyword extends Component
     }
 
     /**
-     * @param OrderKeyword $component The component to be built.
+     * @param OrderKeyword|OrderKeyword[] $component The component to be built.
      *
      * @return string
      */
     public static function build($component)
     {
         if (is_array($component)) {
-            $ret = array();
-            foreach ($component as $c) {
-                $ret[] = static::build($c);
-            }
-            return implode(", ", $ret);
+            return implode(', ', $component);
         } else {
-            return Expression::build($component->expr) . ' ' . $component->type;
+            return $component->expr . ' ' . $component->type;
         }
     }
 }
diff --git a/src/Components/ParameterDefinition.php b/src/Components/ParameterDefinition.php
index 79b4845..d24aefc 100644
--- a/src/Components/ParameterDefinition.php
+++ b/src/Components/ParameterDefinition.php
@@ -130,7 +130,7 @@ class ParameterDefinition extends Component
         }
 
         // Last iteration was not saved.
-        if (!empty($expr->name)) {
+        if ((isset($expr->name)) && ($expr->name !== '')) {
             $ret[] = $expr;
         }
 
@@ -145,18 +145,17 @@ class ParameterDefinition extends Component
      */
     public static function build($component)
     {
-        $ret = array();
-        foreach ($component as $c) {
+        if (is_array($component)) {
+            return '(' . implode(', ', $component) . ')';
+        } else {
             $tmp = '';
-            if (!empty($c->inOut)) {
-                $tmp .= $c->inOut . ' ';
+            if (!empty($component->inOut)) {
+                $tmp .= $component->inOut . ' ';
             }
 
-            $ret[] = trim(
-                $tmp . Context::escape($c->name) . ' ' .
-                DataType::build($c->type)
+            return trim(
+                $tmp . Context::escape($component->name) . ' ' . $component->type
             );
         }
-        return '(' . implode(', ', $ret) . ')';
     }
 }
diff --git a/src/Components/PartitionDefinition.php b/src/Components/PartitionDefinition.php
index df6d3f6..ad31176 100644
--- a/src/Components/PartitionDefinition.php
+++ b/src/Components/PartitionDefinition.php
@@ -198,11 +198,7 @@ class PartitionDefinition extends Component
     public static function build($component)
     {
         if (is_array($component)) {
-            $ret = array();
-            foreach ($component as $c) {
-                $ret[] = static::build($c);
-            }
-            return "(\n" . implode(",\n", $ret) . "\n)";
+            return "(\n" . implode(",\n", $component) . "\n)";
         } else {
             if ($component->isSubpartition) {
                 return 'SUBPARTITION ' . $component->name;
@@ -213,7 +209,6 @@ class PartitionDefinition extends Component
                     . ' VALUES ' . $component->type . ' ' . $component->expr
                     . $subpartitions;
             }
-
         }
     }
 }
diff --git a/src/Components/Reference.php b/src/Components/Reference.php
index 36d3971..3515791 100644
--- a/src/Components/Reference.php
+++ b/src/Components/Reference.php
@@ -145,7 +145,7 @@ class Reference extends Component
         return trim(
             Context::escape($component->table)
             . ' (' . implode(', ', Context::escape($component->columns)) . ') '
-            . OptionsArray::build($component->options)
+            . $component->options
         );
     }
 }
diff --git a/src/Components/RenameOperation.php b/src/Components/RenameOperation.php
index 34c62bb..b8b1691 100644
--- a/src/Components/RenameOperation.php
+++ b/src/Components/RenameOperation.php
@@ -168,14 +168,9 @@ class RenameOperation extends Component
     public static function build($component)
     {
         if (is_array($component)) {
-            $values = array();
-            foreach ($component as $c) {
-                $values[] = static::build($c);
-            }
-            return implode(', ', $values);
+            return implode(', ', $component);
         } else {
-            return Expression::build($component->old) . ' TO '
-                . Expression::build($component->new);
+            return $component->old . ' TO ' . $component->new;
         }
     }
 }
diff --git a/src/Components/SetOperation.php b/src/Components/SetOperation.php
index 8b6af87..d272cab 100644
--- a/src/Components/SetOperation.php
+++ b/src/Components/SetOperation.php
@@ -128,11 +128,7 @@ class SetOperation extends Component
     public static function build($component)
     {
         if (is_array($component)) {
-            $ret = array();
-            foreach ($component as $c) {
-                $ret[] = static::build($c);
-            }
-            return implode(", ", $ret);
+            return implode(', ', $component);
         } else {
             return $component->column . ' = ' . $component->value;
         }
diff --git a/src/Components/UnionKeyword.php b/src/Components/UnionKeyword.php
index cbdb529..8cf8a9f 100644
--- a/src/Components/UnionKeyword.php
+++ b/src/Components/UnionKeyword.php
@@ -30,10 +30,6 @@ class UnionKeyword extends Component
      */
     public static function build($component)
     {
-        $ret = array();
-        foreach ($component as $c) {
-            $ret[] = $c->build();
-        }
-        return implode(" UNION ", $ret);
+        return implode(' UNION ', $component);
     }
 }
diff --git a/src/Lexer.php b/src/Lexer.php
index 1d18399..e4561de 100644
--- a/src/Lexer.php
+++ b/src/Lexer.php
@@ -331,7 +331,7 @@ namespace SqlParser {
                     $pos = $this->last + 1;
 
                     // Parsing the delimiter.
-                    $this->delimiter = '';
+                    $this->delimiter = null;
                     while ((++$this->last < $this->len) && (!Context::isWhitespace($this->str[$this->last]))) {
                         $this->delimiter .= $this->str[$this->last];
                     }
diff --git a/src/Statements/CreateStatement.php b/src/Statements/CreateStatement.php
index bc7cf73..9b07737 100644
--- a/src/Statements/CreateStatement.php
+++ b/src/Statements/CreateStatement.php
@@ -343,7 +343,7 @@ class CreateStatement extends Statement
             )
         );
 
-        if (empty($this->name)) {
+        if ((!isset($this->name)) || ($this->name === '')) {
             $parser->error(
                 __('The name of the entity was expected.'),
                 $list->tokens[$list->idx]
diff --git a/src/Utils/Misc.php b/src/Utils/Misc.php
index 1597648..cec5653 100644
--- a/src/Utils/Misc.php
+++ b/src/Utils/Misc.php
@@ -60,11 +60,12 @@ class Misc
         }
 
         foreach ($expressions as $expr) {
-            if (empty($expr->table)) {
+            if ((!isset($expr->table)) || ($expr->table === '')) {
                 continue;
             }
 
-            $thisDb = empty($expr->database) ? $database : $expr->database;
+            $thisDb = ((isset($expr->database)) && ($expr->database !== '')) ?
+                $expr->database : $database;
 
             if (!isset($retval[$thisDb])) {
                 $retval[$thisDb] = array(
@@ -75,7 +76,8 @@ class Misc
 
             if (!isset($retval[$thisDb]['tables'][$expr->table])) {
                 $retval[$thisDb]['tables'][$expr->table] = array(
-                    'alias' => empty($expr->alias) ? null : $expr->alias,
+                    'alias' => ((isset($expr->alias)) && ($expr->alias !== '')) ?
+                        $expr->alias : null,
                     'columns' => array(),
                 );
             }
@@ -87,20 +89,23 @@ class Misc
         }
 
         foreach ($statement->expr as $expr) {
-            if ((empty($expr->column)) || (empty($expr->alias))) {
+            if ((!isset($expr->column)) || ($expr->column === '')
+                || (!isset($expr->alias)) || ($expr->alias === '')
+            ) {
                 continue;
             }
 
-            $thisDb = empty($expr->database) ? $database : $expr->database;
+            $thisDb = ((isset($expr->database)) && ($expr->database !== '')) ?
+                $expr->database : $database;
 
-            if (empty($expr->table)) {
-                foreach ($retval[$thisDb]['tables'] as &$table) {
-                    $table['columns'][$expr->column] = $expr->alias;
-                }
-            } else {
+            if ((isset($expr->table)) && ($expr->table !== '')) {
                 $thisTable = isset($tables[$thisDb][$expr->table]) ?
                     $tables[$thisDb][$expr->table] : $expr->table;
                 $retval[$thisDb]['tables'][$thisTable]['columns'][$expr->column] = $expr->alias;
+            } else {
+                foreach ($retval[$thisDb]['tables'] as &$table) {
+                    $table['columns'][$expr->column] = $expr->alias;
+                }
             }
         }
 
diff --git a/src/Utils/Query.php b/src/Utils/Query.php
index 5723ec6..4325b65 100644
--- a/src/Utils/Query.php
+++ b/src/Utils/Query.php
@@ -372,7 +372,7 @@ class Query
     {
         $parser = new Parser($query);
 
-        if (!isset($parser->statements[0])) {
+        if (empty($parser->statements[0])) {
             return array();
         }
 
@@ -390,10 +390,12 @@ class Query
             // Finding tables' aliases and their associated real names.
             $tableAliases = array();
             foreach ($statement->from as $expr) {
-                if ((!empty($expr->table)) && (!empty($expr->alias))) {
+                if ((isset($expr->table)) && ($expr->table !== '')
+                    && (isset($expr->alias)) && ($expr->alias !== '')
+                ) {
                     $tableAliases[$expr->alias] = array(
                         $expr->table,
-                        !empty($expr->database) ? $expr->database : null
+                        isset($expr->database) ? $expr->database : null
                     );
                 }
             }
@@ -402,14 +404,15 @@ class Query
             // Sometimes, this is not possible because the tables aren't defined
             // explicitly (e.g. SELECT * FROM film, SELECT film_id FROM film).
             foreach ($statement->expr as $expr) {
-                if (!empty($expr->table)) {
-                    if (empty($tableAliases[$expr->table])) {
+                if ((isset($expr->table)) && ($expr->table !== '')) {
+                    if (isset($tableAliases[$expr->table])) {
+                        $arr = $tableAliases[$expr->table];
+                    } else {
                         $arr = array(
                             $expr->table,
-                            !empty($expr->database) ? $expr->database : null
+                            ((isset($expr->database)) && ($expr->database !== '')) ?
+                                $expr->database : null
                         );
-                    } else {
-                        $arr = $tableAliases[$expr->table];
                     }
                     if (!in_array($arr, $ret['select_tables'])) {
                         $ret['select_tables'][] = $arr;
@@ -424,10 +427,11 @@ class Query
             // extracted from the FROM clause.
             if (empty($ret['select_tables'])) {
                 foreach ($statement->from as $expr) {
-                    if (!empty($expr->table)) {
+                    if ((isset($expr->table)) && ($expr->table !== '')) {
                         $arr = array(
                             $expr->table,
-                            !empty($expr->database) ? $expr->database : null
+                            ((isset($expr->database)) && ($expr->database !== '')) ?
+                                $expr->database : null
                         );
                         if (!in_array($arr, $ret['select_tables'])) {
                             $ret['select_tables'][] = $arr;
@@ -607,7 +611,7 @@ class Query
             }
 
             if ($brackets == 0) {
-                // Checking if we changed sections.
+                // Checking if the section was changed.
                 if (($token->type === Token::TYPE_KEYWORD)
                     && (isset($clauses[$token->value]))
                     && ($clauses[$token->value] >= $currIdx)
diff --git a/tests/Components/CreateDefinitionTest.php b/tests/Components/CreateDefinitionTest.php
index 81c8ba8..a7b7f86 100644
--- a/tests/Components/CreateDefinitionTest.php
+++ b/tests/Components/CreateDefinitionTest.php
@@ -19,7 +19,7 @@ class CreateDefinitionTest extends TestCase
         $this->assertEquals('str', $component[0]->name);
         $this->assertEquals('FULLTEXT INDEX', $component[1]->key->type);
         $this->assertEquals('indx', $component[1]->key->name);
-        $this->assertEquals('FULLTEXT INDEX `indx` (`str`)', $component[1]);
+        $this->assertEquals('FULLTEXT INDEX `indx` (`str`)', (string) $component[1]);
     }
 
     public function testParseErr1()
diff --git a/tests/Components/ExpressionTest.php b/tests/Components/ExpressionTest.php
index 01492fd..863d914 100644
--- a/tests/Components/ExpressionTest.php
+++ b/tests/Components/ExpressionTest.php
@@ -60,7 +60,13 @@ class ExpressionTest extends TestCase
 
     public function testBuild()
     {
-        $component = new Expression('1 + 2', 'three');
-        $this->assertEquals(Expression::build($component), '1 + 2 AS `three`');
+        $component = array(
+            new Expression('1 + 2', 'three'),
+            new Expression('1 + 3', 'four')
+        );
+        $this->assertEquals(
+            Expression::build($component),
+            '1 + 2 AS `three`, 1 + 3 AS `four`'
+        );
     }
 }
diff --git a/tools/TestGenerator.php b/tools/TestGenerator.php
index 1d1be2d..d833463 100644
--- a/tools/TestGenerator.php
+++ b/tools/TestGenerator.php
@@ -158,9 +158,11 @@ class TestGenerator
 
                 // Creating required directories to maintain the structure.
                 // Ignoring errors if the folder structure exists already.
-                @mkdir($outputFile);
-                if ($debug !== null) {
-                    @mkdir($debugFile);
+                if (!is_dir($outputFile)) {
+                    mkdir($outputFile);
+                }
+                if (($debug !== null) && (!is_dir($debugFile))) {
+                    mkdir($debugFile);
                 }
 
                 // Generating tests recursively.