Purpose

Linked issue: close #155

Add ReadBuilder::with_filter(Predicate) and wire partition predicate evaluation into TableScan::plan_snapshot to prune manifest entries by partition values, using the split-then-evaluate approach aligned with Java Paimon's splitPartitionPredicatesAndDataPredicates.

Brief change log

• Add Predicate enum, Datum, PredicateOperator, and PredicateBuilder with name-based field resolution and type validation
• Add ReadBuilder::with_filter(Predicate) to accept user filters
• Wire partition predicate evaluation into TableScan::plan_snapshot using split-then-evaluate: split at AND boundaries, remap partition-only conjuncts, evaluate against partition BinaryRow, with result caching
• Error handling: BinaryRow decode failure → fail-open; eval_row error → fail-fast

Tests

API and Format

New public API additions:

• Datum, PredicateOperator, Predicate, PredicateBuilder — public types in paimon::spec
• field_idx_to_partition_idx() — public utility function
• ReadBuilder::with_filter(Predicate) — new builder method

Documentation