Enum PatternAst

enum PatternAst {
    Literal {
        op: UnaryOp,
        pattern: String,
    },
    Binary {
        op: BinaryOp,
        children: Vec<PatternAst>,
    },
    Group {
        op: UnaryOp,
        child: Box<PatternAst>,
    },
}

Variants

Literal

A leaf node that matches a column with pattern

Fields

op: UnaryOp

pattern: String

Binary

Flattened binary chains

Fields

op: BinaryOp

children: Vec<PatternAst>

Group

A sub-tree enclosed by parenthesis

Fields

op: UnaryOp

child: Box<PatternAst>

Implementations

impl PatternAst

fn into_like_expr(self, column: &str) -> Expr

fn convert_literal(column: &str, pattern: &str) -> Expr

fn escape_pattern(pattern: &str) -> String

fn transform_ast(self) -> Result<Self>

Transform this AST with preset rules to make it correct.

fn collapse_binary_branch_fn(self) -> DfResult<Transformed<Self>>

Collapse binary branch with the same operator. I.e., this transformer changes the binary-tree AST into a multiple branching AST.

This function is expected to be called in a bottom-up manner as it won’t recursion.

fn eliminate_optional_fn(self) -> DfResult<Transformed<Self>>

Eliminate optional pattern. An optional pattern can always be omitted or transformed into a must pattern follows the following rules:

• If there is only one pattern and it’s optional, change it to must
• If there is any must pattern, remove all other optional patterns

fn eliminate_single_child_fn(self) -> DfResult<Transformed<Self>>

Eliminate single child PatternAst::Binary node. If a binary node has only one child, it can be replaced by its only child.

This function prefers to be applied in a top-down manner. But it’s not required.

Trait Implementations

impl Clone for PatternAst

fn clone(&self) -> PatternAst

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for PatternAst

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for PatternAst

fn eq(&self, other: &PatternAst) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl TreeNode for PatternAst

fn apply_children<'n, F: FnMut(&'n Self) -> DfResult<TreeNodeRecursion>>( &'n self, f: F, ) -> DfResult<TreeNodeRecursion>

Low-level API used to implement other APIs.

fn map_children<F: FnMut(Self) -> DfResult<Transformed<Self>>>( self, f: F, ) -> DfResult<Transformed<Self>>

Low-level API used to implement other APIs.

fn visit<'n, V>( &'n self, visitor: &mut V, ) -> Result<TreeNodeRecursion, DataFusionError>

where V: TreeNodeVisitor<'n, Node = Self>,

Visit the tree node with a [TreeNodeVisitor], performing a depth-first walk of the node and its children.

fn rewrite<R>( self, rewriter: &mut R, ) -> Result<Transformed<Self>, DataFusionError>

where R: TreeNodeRewriter<Node = Self>,

Rewrite the tree node with a [TreeNodeRewriter], performing a depth-first walk of the node and its children.

fn apply<'n, F>(&'n self, f: F) -> Result<TreeNodeRecursion, DataFusionError>

where F: FnMut(&'n Self) -> Result<TreeNodeRecursion, DataFusionError>,

Applies f to the node then each of its children, recursively (a top-down, pre-order traversal).

fn transform<F>(self, f: F) -> Result<Transformed<Self>, DataFusionError>

where F: FnMut(Self) -> Result<Transformed<Self>, DataFusionError>,

Recursively rewrite the node’s children and then the node using f (a bottom-up post-order traversal).

fn transform_down<F>(self, f: F) -> Result<Transformed<Self>, DataFusionError>

where F: FnMut(Self) -> Result<Transformed<Self>, DataFusionError>,

Recursively rewrite the tree using f in a top-down (pre-order) fashion.

fn transform_down_mut<F>( self, f: &mut F, ) -> Result<Transformed<Self>, DataFusionError>

where F: FnMut(Self) -> Result<Transformed<Self>, DataFusionError>,

👎Deprecated since 38.0.0: Use transform_down instead

Same as [Self::transform_down] but with a mutable closure.

fn transform_up<F>(self, f: F) -> Result<Transformed<Self>, DataFusionError>

where F: FnMut(Self) -> Result<Transformed<Self>, DataFusionError>,

Recursively rewrite the node using f in a bottom-up (post-order) fashion.

fn transform_up_mut<F>( self, f: &mut F, ) -> Result<Transformed<Self>, DataFusionError>

where F: FnMut(Self) -> Result<Transformed<Self>, DataFusionError>,

👎Deprecated since 38.0.0: Use transform_up instead

Same as [Self::transform_up] but with a mutable closure.

fn transform_down_up<FD, FU>( self, f_down: FD, f_up: FU, ) -> Result<Transformed<Self>, DataFusionError>

where FD: FnMut(Self) -> Result<Transformed<Self>, DataFusionError>, FU: FnMut(Self) -> Result<Transformed<Self>, DataFusionError>,

Transforms the node using f_down while traversing the tree top-down (pre-order), and using f_up while traversing the tree bottom-up (post-order).

fn exists<F>(&self, f: F) -> Result<bool, DataFusionError>

where F: FnMut(&Self) -> Result<bool, DataFusionError>,

Returns true if f returns true for any node in the tree.

impl Eq for PatternAst

impl StructuralPartialEq for PatternAst