Microsoft Technology Licensing, LLC

Oracle International Corporation

Gavin Mark Bierman

Brian Goetz

John Robert Rose

Henricus Johannes Maria Meijer

Donald F Box

Bradford H Lovering

David E Langworthy

Andrew Donald Gordon

Jeffrey C Schlimmer

John David Doty

Wolfram Schulte

Anders Hejlsberg

Matthew J Warren

Amanda K Silver

Mads Torgersen

Paul Allen Vick, Jr

Peter A Hallam

Danny Van Velzen

Guy L Steele

Robert Eric Lippert

Techniques for accessing a migrated method include: identifying a request to invoke a method defined by a particular type; identifying, in the particular type: an older version of the method that is (a) associated with a method name and (b) configured to return values of a first return type, and a current version of the method that is (a) associated with the method name and (b) configured to return values of a second return type; determining that the first request specifies the first return type; responsive to determining that the first request specifies the first return type: executing the current version of the method to obtain a value of the second return type; applying one or more conversion functions to convert the value of the second return type to a value of the first return type; returning the value of the first return type responsive to the first request.

Accessing a migrated member in an updated type

Techniques for accessing a migrated method include: identifying a request to invoke a method defined by a type, the request including one or more arguments associated with respective argument types; identifying, in the type, an older version of the method associated with (a) a method name and (b) a first set of one or more parameter types, and a current version of the method associated with (a) the method name and (b) a second set of one or more parameter types; determining that the argument type(s) match(es) the first set of one or more parameter types; responsive to determining that the argument type(s) match(es) the first set of one or more parameter types: applying one or more conversion functions to convert the argument(s) to the second set of one or more parameter types; executing the current version of the method using the converted argument(s).

Accessing migrated members in an updated type is described. Instructions to access a migrated member may be: (a) storing a value of a particular type as a value of a migrated field, or (b) invoking a migrated method using an argument of a particular type. The argument of the particular type, specified in the instructions, is converted into a value of the type associated with the current version of the migrated member. The migrated member is accessed using the converted value. Alternatively, instructions may be: (a) fetching and returning a value of a migrated field as a value of a particular type, or (b) returning a value from a migrated method as a value of a particular type. A value is returned via accessing the current version of the migrated member. The returned value is converted into a value of the particular type specified in the instructions.

Overriding a migrated method in an updated type is described. Instructions to invoke a particular method, in a sub-type, that overrides a migrated method, in a super-type, are identified. The instructions may invoke the particular method using a set of arguments associated with a particular set of types. The particular set of types is different from the set of parameter types associated with the particular method as defined in the sub-type. Additionally or alternatively, the instructions may include returning a value of a particular type from the particular method. The particular type is different from the return type associated with the particular method as defined in the sub-type. A new method is generated. The new method includes instructions for (a) converting the set of arguments and/or (b) converting the value returned from the particular method. The new method is stored in a runtime environment and executed.

Overriding a migrated method in an updated type

Techniques for flow-based scoping are disclosed. A first code segment in a sequence of same-level code segments encapsulates a first lower-level lexical scope. The first lower-level scope is inclusive of scoping provided for the sequence of same-level code segments. The first code segment comprises a condition and an uninitialized variable. If executed, the first code segment causes the condition to be evaluated. If the condition is satisfied, the uninitialized variable is initialized and made available only within the first lower-level lexical scope. If a second code segment (a) references the uninitialized variable and (b) is in the sequence of same-level code segments or in a second lower-level lexical scope outside of the first lower-level lexical scope, an error message is presented indicating that the uninitialized variable is out of scope for the second code segment.

Flow-based scoping

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.

Type system for declarative data scripting language

An efficient, logical and expressive 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. A bidirectional type checking algorithm is provided for the type system including synthesis and checking steps to statically verify types of code based on the type system.

Bidirectional type checking for declarative data scripting language

An efficient, logical and expressive 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. Various embodiments verify the validity of subtyping relationships by translating to first-order logic, and invoking a general-purpose theorem prover with the first-order logic as input. In contrast to treating formulas as types, types are translated into formulas of standard first-order logic. Moreover, to represent data structures of the programming language as first-order logic, universal and existential quantifiers of first-order logic, and function symbols in terms, are exploited. Data intensive applications can be generated, verified, and deployed with greater speed and scale.

Semantic subtyping for declarative data scripting language by calling a prover

A set of syntactic extensions that are compiled with a type-directed translation method to facilitate lifting member access on base types to a newly constructed type. The extensions are processed with a type system that facilitates seamless data access to relational and semi-structured data in an object oriented host language.

Compositional lifting of operations over structural types

Systems and methods facilitate type inference in a computer-programming environment. Type inference can be applied to generic method or function invocation in object-oriented languages to determine a type argument list left implicit by a programmer. One or more type arguments can be identified as a parameter type to which all other types in a set of associated parameter types can be converted.

Type inference for object-oriented languages

A type system that facilitates seamless integration of data access to relational and semi-structured data in an object oriented host language. A data access component includes the type system and corresponding set of syntax constructions that facilitates coercive subtyping and restricts covariance to identity conversions.

Growing community of inventors

Cambridge, United Kingdom

Gavin Mark Bierman