Microsoft Technology Licensing, LLC

Microsoft Corporation

Mads Torgersen

Anders Hejlsberg

Matthew J Warren

Henricus Johannes Maria Meijer

Dinesh Chandrakant Kulkarni

Stephen Harris Toub

Neal M Gafter

Lucas James Hoban

Steven E Lucco

Niklas Gustafsson

Peter A Hallam

Charles P Jazdzewski

Jared Porter Parsons

Joseph Pamer

Robert Eric Lippert

Avner Y Aharoni

Erik Meijer

David N Schach

Samuel Ng

John Wesley Dyer

Peter H Golde

Aleksey V Tsingauz

James J Hugunin

Dmitry Lomov

Lucian Wischik

Christopher Joseph Burrows

Karen Liu

Renaud Paquay

Clemens Alden Szyperski

Amanda K Silver

Eric Lynn Eilebrecht

Luca Bolognese

David Charles Wrighton

Paul Allen Vick, Jr

Danny Van Velzen

Gavin Mark Bierman

Jomo Fisher

Terry A Adams

Daigo Hamura

Julien Couvreur

Kevin Pilch-Bisson

Alex Christopher Turner

Martin Maly

Kevin Andrew Pilch

Lucian Jules Wishchik

Utilizing role types that extend underlying types. Within a program definition, a computer system identifies a statement assigning an object of an underlying type to a role type that extends the underlying type. The underlying type implements a first interface, and the role type implements a second interface. Based on the role type extending the underlying type, the computer system assigns the object of the underlying type to the role type. Based on assigning the object of the underlying type to the role type, the role type is usable to interact with the object of the underlying type using both the first interface and the second interface.

Runtime support for role types that extend underlying types

A single asynchronous enumerable object is generated that contains the data and methods needed to iterate through an enumerable asynchronously. The asynchronous enumerable object contains the code for traversing the enumerable one step at a time and the operations needed to suspend an iteration to await completion of an asynchronous operation and to resume the iteration upon completion of the asynchronous operation. The allocation of a single object to perform all of these tasks reduces the memory consumption needed to execute an asynchronous enumeration.

Compiler-generated asynchronous enumerable object

Efficient immutable syntax representation with parent pointers under incremental change is enabled by creating a data structure comprising at least one tree structure that allows both upward and downward references in the tree and a tree structure that is immutable (read-only), and allows parts of itself to be re-used in other data structures. The data structure described enables tools to search and target particular sub trees. The fragment of the tree representing the targeted sub tree is produced as it is used. The rest of the tree is not produced. The read-only tree retains relative information, allowing it to be reassembled and shared.

Efficient immutable syntax representation with incremental change

Static type checking can be performed on types and values defined in modules in a system that dynamically composes programs from modules. The types and values do not share a global namespace. Each module defines its own module universe, disjoint from other modules. A language mechanism can establish a local name binding to one module within the content of another module. When type checking at compile time an environment can be established that corresponds to a runtime instance of the program. The static type system can be arranged to align with the runtime values, such that the names used to refer to objects at runtime are the same as the names used to refer to the types of those objects in the static type system. Aliases of a particular type are resolved to a known compile time description of the type.

Static type checking across module universes

Type inference is used to provide the benefits of static type checking without explicitly declaring type in the source code. Type inference that proceeds in a bottom up direction is augmented by contextual typing that proceeds in a top down direction. Contextual typing types enclosed expressions by associating the type of a directly enclosing expression with the enclosed expression. Object literals, function literals and array literals enclosed in assignment and call expressions, can be contextually typed.

Contextual typing

Statically extensible types allow a static type system to model the behavior of dynamic object model extension in dynamic runtime systems. Static types that model dynamically extended types can be extended using additional declarations in the same compilation. Declarations for a particular type can come from multiple independent sources which can have been defined at multiple points in time. Extension declarations can use the same syntax as the initial type declaration. Hence presence of one or more declarations for the same type in a compilation can indicate that the type has been extended. These features allow static type checking of dynamic plug-ins to be supported using statically extensible types. Declarations and extension declarations for a type can be merged together to create an extended type that enables different processing paths and dependencies.

Statically extensible types

A static type, called 'dynamic', is introduced into a statically bound programming language. An expression or subexpression that is defined as a static type called 'dynamic' in the source code of a program written in the statically bound programming language, is bound based on its runtime type instead of on its compile time type. Binding can be performed based on a mixture of compile time and runtime types that are based on the specification of types of expressions in source code. This type of binding is called hybrid binding. Operations are bound using the runtime type of constituent expressions (i.e., the runtime type of a receiver, an argument, or an operand) typed as dynamic and the compile time type of static constituents. If any constituent expression of an operation is dynamic, binding occurs at runtime instead of at compile time.

Dynamic binding directed by static types

Unsuspended co-routines are handled by the machine call stack mechanism in which the stack grows and shrinks as recursive calls are made and returned from. When a co-routine is suspended, however, additional call stack processing is performed. A suspension message is issued, and the entire resume-able part of the call stack is removed, and is copied to the heap. A frame that returns control to a driver method (a resumer) is copied to the call stack so that resumption of the co-routine does not recursively reactivate the whole call stack. Instead the resumer reactivates only the topmost or most current frame called the leaf frame. When a co-routine is suspended, it does not return to its caller, but instead returns to the resumer that has reactivated it.

Efficient resumption of co-routines on a linear stack

The present invention extends to methods, systems, and computer program products for transforming source code to await execution of asynchronous operations. Embodiments of the invention simplify authoring and use of asynchronous methods, by generating statements that use well-defined awaitable objects to await completion of asynchronous operations. For example, a computer system can transform a statement that requests to await the completion of an asynchronous operation into a plurality of statements that use a predefined pattern of members of an awaitable object corresponding the asynchronous operation. The pattern can include one or more members configured to return a completion status of the asynchronous operation, one or more members configured to resume execution of the asynchronous method at a resumption point when the asynchronous operation completes, and one or more members configured to retrieve completion results. Accordingly, the plurality of statements can use these members to await execution of the asynchronous operation.

Pattern-based compilation of asynchronous consumption

Queries targeting various data sources are processed in a query processing pipeline that parses the query into a set of operations (e.g., an expression tree or a translated SQL query) using a set of query operators, each handling a particular type of operation. The query operators are often designed in an unspecialized manner, such that each query operator handles one query operation in an atomic, generic manner (e.g., sorting generic data items for an ORDER BY clause.) More efficient queries may be devised by including specialized queries that operate in common but special cases, such as a sorting of a particular data type (e.g., a floating-point number sort) or a sequence of two or more operations that are often performed together (e.g., a WHERE test of an attribute followed by a SELECT of the same attribute.) The use of specialized operators may result in the formulation of more efficient queries.

Query processing with specialized query operators

A design time debugging tool provides debugging information available from the compiler during design time, as if a user were debugging code that provided the debugging information, by exposing information available from the compiler without initiation of a debugging session and without executing the program being debugged.

Time debugging

The present invention extends to methods, systems, and computer program products for representing various programming elements with compiler-generated tasks. Embodiments of the invention enable access to the future state of a method through a handle to a single and composable task object. For example, an asynchronous method is rewritten to generate and return a handle to an instance of a builder object, which represents one or more future states of the asynchronous method. Information about operation of the asynchronous method is then passed through the handle. Accordingly, state of the asynchronous method is trackable prior to and after completing.

Using compiler-generated tasks to represent programming elements

APIs are provided, that are external to a programming language but that provide functionality that can be plugged into a language compiler. The provided APIs tailor functionality associated with asynchronous programming, iterators or writing symmetric co-routines using a generalized pattern-based approach. Several types of resumable methods are provided in the APIs which can be applied to method bodies written in traditional program code. Syntactically distinguishable control points in method bodies written in traditional program code invoke transformation of the code by the compiler using the external APIs. The transformed code enables the pausing and resumption of the code sandwiched between control points in the transformed code. The source code contained within a method having control points in it is transformed so that code within the method can be executed in discrete parts, each part starting and ending at a control point in the transformed code.

Resumable methods

A method of providing asynchronous programming support at run time for scope-based ambient state at a method call is disclosed. In response to the method call, an asynchronous method stack frame is created along with ambient state for the asynchronous method call. In one example of the method, a current frame of a method stack is captured. A new frame is instantiated by setting a previous reference of the new frame to the current frame and moving data from the previous frame into the current frame. One example of instantiating the new frame includes pushing the current frame onto the stack. In another example, the new frame is lazily created when changes have been made. A state machine used to transform the synchronously-created method into an asynchronous method is moved from a current state to a next state. The captured frame is restored.

Ambient state for asynchronous methods

Growing community of inventors

Issaquah, WA, United States of America

Mads Torgersen