The narrowest possible type that is produced when this expression is evaluated.
The narrowest possible type that is produced when this expression is evaluated.
Returns a Seq of the children of this node
Returns a Seq of the children of this node
The output element data types in structure of Seq[(DataType, Nullable)] TODO we probably need to add more information like metadata etc.
Should be implemented by child classes to perform specific Generators.
Should be implemented by child classes to perform specific Generators.
Returns the tree node at the specified number.
Returns the tree node at the specified number. Numbers for each node can be found in the numberedTreeString.
Returns a string representing the arguments to this node, minus any children
Returns a string representing the arguments to this node, minus any children
Returns a 'scala code' representation of this TreeNode
and its children.
Returns a 'scala code' representation of this TreeNode
and its children. Intended for use
when debugging where the prettier toString function is obfuscating the actual structure. In the
case of 'pure' TreeNodes
that only contain primitives and other TreeNodes, the result can be
pasted in the REPL to build an equivalent Tree.
Returns true if all the children of this expression have been resolved to a specific schema and false if any still contains any unresolved placeholders.
Returns true if all the children of this expression have been resolved to a specific schema and false if any still contains any unresolved placeholders.
Returns a Seq containing the result of applying a partial function to all elements in this tree on which the function is defined.
Returns a Seq containing the result of applying a partial function to all elements in this tree on which the function is defined.
Finds and returns the first TreeNode of the tree for which the given partial function is defined (pre-order), and applies the partial function to it.
Returns the DataType of the result of evaluating this expression.
Returns the DataType of the result of evaluating this expression. It is
invalid to query the dataType of an unresolved expression (i.e., when resolved
== false).
Returns true when the current expression always return the same result for fixed input values.
Returns true when the current expression always return the same result for fixed input values.
Faster version of equality which short-circuits when two treeNodes are the same instance.
Faster version of equality which short-circuits when two treeNodes are the same instance.
We don't just override Object.equals, as doing so prevents the scala compiler from
generating case class equals
methods
Find the first TreeNode that satisfies the condition specified by f
.
Returns a Seq by applying a function to all nodes in this tree and using the elements of the resulting collections.
Returns a Seq by applying a function to all nodes in this tree and using the elements of the resulting collections.
Returns true when an expression is a candidate for static evaluation before the query is executed.
Returns true when an expression is a candidate for static evaluation before the query is executed.
The following conditions are used to determine suitability for constant folding:
Runs the given function on this node and then recursively on children.
Runs the given function recursively on children then on this node.
Appends the string represent of this node and its children to the given StringBuilder.
Appends the string represent of this node and its children to the given StringBuilder.
Creates a copy of this type of tree node after a transformation.
Creates a copy of this type of tree node after a transformation. Must be overridden by child classes that have constructor arguments that are not present in the productIterator.
the new product arguments.
Returns a Seq containing the result of applying the given function to each node in this tree in a preorder traversal.
Returns a Seq containing the result of applying the given function to each node in this tree in a preorder traversal.
the function to be applied.
Returns a copy of this node where f
has been applied to all the nodes children.
Returns a copy of this node where f
has been applied to all the nodes children.
Returns the name of this type of TreeNode.
Returns the name of this type of TreeNode. Defaults to the class name.
Returns a string representation of the nodes in this tree, where each operator is numbered.
Args to the constructor that should be copied, but not transformed.
Args to the constructor that should be copied, but not transformed. These are appended to the transformed args automatically by makeCopy
Returns a string representation of this expression that does not have developer centric debugging information like the expression id.
Returns a string representation of this expression that does not have developer centric debugging information like the expression id.
Returns true
if this expression and all its children have been resolved to a specific schema
and false
if it still contains any unresolved placeholders.
Returns true
if this expression and all its children have been resolved to a specific schema
and false
if it still contains any unresolved placeholders. Implementations of expressions
should override this if the resolution of this type of expression involves more than just
the resolution of its children.
Returns true when two expressions will always compute the same result, even if they differ cosmetically (i.e.
Returns true when two expressions will always compute the same result, even if they differ cosmetically (i.e. capitalization of names in attributes may be different).
String representation of this node without any children
String representation of this node without any children
The arguments that should be included in the arg string.
The arguments that should be included in the arg string. Defaults to the productIterator
.
Notifies that there are no more rows to process, clean up code, and additional rows can be made here.
Returns a copy of this node where rule
has been recursively applied to the tree.
Returns a copy of this node where rule
has been recursively applied to the tree.
When rule
does not apply to a given node it is left unchanged.
Users should not expect a specific directionality. If a specific directionality is needed,
transformDown or transformUp should be used.
the function use to transform this nodes children
Returns a copy of this node where rule
has been recursively applied to all the children of
this node.
Returns a copy of this node where rule
has been recursively applied to all the children of
this node. When rule
does not apply to a given node it is left unchanged.
the function used to transform this nodes children
Returns a copy of this node where rule
has been recursively applied to it and all of its
children (pre-order).
Returns a copy of this node where rule
has been recursively applied to it and all of its
children (pre-order). When rule
does not apply to a given node it is left unchanged.
the function used to transform this nodes children
Returns a copy of this node where rule
has been recursively applied first to all of its
children and then itself (post-order).
Returns a copy of this node where rule
has been recursively applied first to all of its
children and then itself (post-order). When rule
does not apply to a given node, it is left
unchanged.
the function use to transform this nodes children
Returns a string representation of the nodes in this tree
Returns a string representation of the nodes in this tree
Returns a copy of this node with the children replaced.
Returns a copy of this node with the children replaced. TODO: Validate somewhere (in debug mode?) that children are ordered correctly.
An expression that produces zero or more rows given a single input row.
Generators produce multiple output rows instead of a single value like other expressions, and thus they must have a schema to associate with the rows that are output.
However, unlike row producing relational operators, which are either leaves or determine their output schema functionally from their input, generators can contain other expressions that might result in their modification by rules. This structure means that they might be copied multiple times after first determining their output schema. If a new output schema is created for each copy references up the tree might be rendered invalid. As a result generators must instead define a function
makeOutput
which is called only once when the schema is first requested. The attributes produced by this function will be automatically copied anytime rules result in changes to the Generator or its children.