Type system for declarative data scripting language

摘要

An efficient, logical and expressive type system is provided for flexibly defining types of a declarative programming language so that efficient and structurally compact data intensive applications can be generated. The type system supports the combination of refinement types and type membership expressions, as well as a top type that encompasses all valid values as members. With the type system, types can be expressed as intersections and/or unions of other types. Thus, types can be efficiently represented for a full range of types of data as may be found in real world data stores.

主权项

1. A method for defining declarative code according to a declarative programming model comprising a type system supporting type refinement and type membership, including:
receiving a specification of at least one programming construct of a declarative programming language including receiving a specification of a type refinement construct that defines at least one type by specifying values for which a Boolean expression is true, and receiving, within a first expression of the type refinement construct, a specification of a type membership test construct that determines whether one or more resulting values of evaluating a second expression that is included in the first expression is a member of an indicated type; and generating a machine readable representation of code based on the specification of the at least one programming construct, one or more judgments associated with the type membership test being associated with the first expression, the one or more judgments being based on at least one context associated with at least one type.