v0.2.0

This release is highlighted by the addition of end-to-end PartiQL query evaluation. This release introduces a logical plan and evaluation API along with AST lowering to logical plan with name resolution. There are some breaking changes to the parsed AST.

Changed

• BREAKING: Refactors the AST
  • Removes Location from the AST, replacing with a 'node id' that gives the AST node identity; the id can be used to retrieve Location
  • Removes redundancies and extraneous nesting
  • Refactor some AST nodes (including FROM, WHERE, and HAVING clauses) for better visitation
  • Refactor FromSource to not wrap in AstNode

Added

• Adds end-to-end PartiQL query evaluation with the following supported features
  • SELECT-FROM-WHERE
  • LATERAL LEFT, INNER, CROSS JOINs
  • UNPIVOT
  • SELECT VALUE
  • Query expressions
  • List, Bag, Tuple constructors
  • Path expressions (wildcard & unpivot path are not yet supported)
  • Subquery (supported in logical and eval plan; not yet in AST to plan conversion)
  • DISTINCT
  • Variable references
  • Literals
  • Arithmetic operators (+, -, *, /, %)
  • Logical operators (AND, OR, NOT)
  • Equality operators (= , !=)
  • Comparison operators (<, >, <=, >=)
  • IS [NOT] MISSING, IS [NOT] NULL
  • IN
  • BETWEEN
  • LIKE
  • Searched and simple case expressions
  • COALESCE and NULLIF
  • CONCAT
  • And the following functions
    • LOWER
    • UPPER
    • CHARACTER_LENGTH
    • LTRIM
    • BTRIM
    • RTRIM
    • SUBSTRING
    • EXISTS
• Adds Visit and Visitor traits for visiting AST
• Add AST node Visit impls via proc_macros
• Adds PartiQL Value, an in-memory representation of PartiQL values
  • Supports PartiQL values other than DATE, TIME, s-expressions
  • Supports basic arithmetic, logical, equality, and comparison operators
  • Supports partiql parsing of Ion into Value
• Defines logical plan and evaluation DAG
• AST lowering to logical plan with name resolution
• partiql-conformance-tests support for parsing and running evaluation tests from partiql-tests