Package org.apache.iceberg.expressions

Class Binder

java.lang.Object

org.apache.iceberg.expressions.Binder

public class Binder
extends Object

Rewrites expressions by replacing unbound named references with references to fields in a struct schema.

Method Summary

Modifier and Type	Method	Description
static Expression	bind(Types.StructType struct, Expression expr, boolean caseSensitive)	Replaces all unbound/named references with bound references to fields in the given struct.
static Set<Integer>	boundReferences(Types.StructType struct, List<Expression> exprs, boolean caseSensitive)
static boolean	isBound(Expression expr)	Returns whether an expression is bound.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

bind

public static Expression bind(Types.StructType struct,
 Expression expr,
 boolean caseSensitive)

Replaces all unbound/named references with bound references to fields in the given struct.

When a reference is resolved, any literal used in a predicate for that field is converted to the field's type using Literal.to(Type). If automatic conversion to that type isn't allowed, a validation exception is thrown.

The result expression may be simplified when constructed. For example, isNull("a") is replaced with alwaysFalse() when "a" is resolved to a required field.

The expression cannot contain references that are already bound, or an IllegalStateException will be thrown.

Parameters:

struct - The struct type to resolve references by name.

expr - An expression to rewrite with bound references.

caseSensitive - A boolean flag to control whether the bind should enforce case sensitivity.

Returns:

the expression rewritten with bound references

Throws:

ValidationException - if literals do not match bound references

IllegalStateException - if any references are already bound

boundReferences

public static Set<Integer> boundReferences(Types.StructType struct,
 List<Expression> exprs,
 boolean caseSensitive)

isBound

public static boolean isBound(Expression expr)

Returns whether an expression is bound.

An expression is bound if all of its predicates are bound.

Parameters:

expr - an Expression

Returns:

true if the expression is bound

Throws:

IllegalArgumentException - if the expression has both bound and unbound predicates.