Downloaded 84 times
![How does it work?
What is a classifier?
type Classifier<'T> =
ClassifyFunc of ((DateTime * float)[] -> 'T)
A function value!
Given data, calculate the result
Generic – can produce any value
Abstract – representation is hidden](https://image.slidesharecdn.com/dsls-130227182823-phpapp01/75/Creating-Domain-Specific-Languages-in-F-20-2048.jpg)
![F# active patterns
Extending the pattern language
match input with
| Bracketed '*' '*' (body, rest) -> (...)
| Bracketed '[' ']' (body,
Bracketed '(' ')' (link, rest)) -> (...)
| _ -> (...)
Parsing Markdown format
Detecting character patterns
Detecting multi-line patterns
See more at http://manning.com/petricek2](https://image.slidesharecdn.com/dsls-130227182823-phpapp01/75/Creating-Domain-Specific-Languages-in-F-27-2048.jpg)
![How does it work?
What is a classifier?
type Classifier<'T> =
ClassifyFunc of ((DateTime * float)[] -> 'T)
A function value!
Given data, calculate the result
Generic – can produce any value
Abstract – representation is hidden](https://crownmelresort.com/image.slidesharecdn.com/dsls-130227182823-phpapp01/75/Creating-Domain-Specific-Languages-in-F-20-2048.jpg)
![F# active patterns
Extending the pattern language
match input with
| Bracketed '*' '*' (body, rest) -> (...)
| Bracketed '[' ']' (body,
Bracketed '(' ')' (link, rest)) -> (...)
| _ -> (...)
Parsing Markdown format
Detecting character patterns
Detecting multi-line patterns
See more at http://manning.com/petricek2](https://crownmelresort.com/image.slidesharecdn.com/dsls-130227182823-phpapp01/75/Creating-Domain-Specific-Languages-in-F-27-2048.jpg)
Uploaded byTomas Petricek
Creating Domain Specific Languages in F#
The document discusses the creation of domain-specific languages (DSLs) using F#, detailing their advantages, disadvantages, and practical examples in areas like finance and data processing. It emphasizes the distinction between internal and external DSLs, providing insights into how to model languages, define primitives and combinators, and create custom syntax. Additionally, it includes demonstrations related to option pricing and pattern detection, along with resources for further learning and community engagement.
In this document
Powered by AI
Introduction to F#, roles, industry applications, community support, and training resources.
Definition, purpose, and examples of DSLs, contrasting them with general-purpose languages.
Building a DSL for option pricing with focus on primitives and diagramming capabilities.
Discussion on advantages, disadvantages, and specific characteristics of internal and external DSLs.
Constructing a DSL for detecting price patterns, highlighting combinators and classifiers.
Classifier functions, advanced techniques, meta-programming, and monadic expressions in F#.
Utilizing F# for complex pattern matching and query expressions in DSLs.
Summary of contents and a guide on building DSLs, along with additional resources.
More Related Content
Similar to Creating Domain Specific Languages in F#
Creating Domain Specific Languages in F#
- 1. Creating Domain Specific Languages in F# PhD student @ University of Cambridge tomas@tomasp.net Tomas Petricek @tomaspetricek Conspirator behind http://fsharp.org
- 2. Real World Functional Programming tutorials F# and C# monads functional concepts practical examples industry experts F# Deep Dives . domain modeling financial & insurance web & data actor model concurrency social gaming F# Trainings & Consulting testing London async & concurrent New York DSLs data processing http://functional-programming.net
- 3. software stacks trainings teaching F# user groups snippets mac and linux cross-platform books and tutorials F# Software Foundation F# community open-source MonoDevelop http://www.fsharp.org contributions research support consultancy mailing list
- 4. Domain-specific languages We havea class of problems Create a language for the class Use language to solve them DSLs and functional languages Internal DSLs are just library External DSLs are easier to build
- 5. Domain-specific languages Language forsolving specific problems Fun.cylinder |> Fun.translate (0, 0, 1) |> Fun.color Color.Gold $ Fun.cone |> Fun.color Color.DarkRed Contrast with general purpose languages
- 6. Demo: Building acastle Domain Specific Language Defines a few simple primitives Extensible by composition Single-purpose or general-purpose? Most code is single-purpose Can use general-purpose if needed See also FAKE: the F# Make
- 7. Building a DSLfor: Option Pricing
- 8. Demo: Modeling Eurooptions What is the language? Primitive values Composition operations How do we use the model? Drawing a pay-off diagram Calculating option price Checking for execution
- 9.
- 10. Building the model Primitivesof the language type OptionKind = Call | Put type Option = | European of OptionKind * float Composition combinators | Combine of Option * Option | Times of float * Option
- 11. Demo: Building &using the DSL Make it more convenient Custom operators Derived primitives Use it for its purpose Drawing pay-off diagrams Evaluating option price
- 12. Domain-specific languages Advantages Disadvantages Readability Additional abstraction Greater for External DSL Smaller for Internal DSL Maintainability Time to implement Hides the implementation Easier for Internal DSL Internals can be changed Time to learn Domain Focus Avoid crazy operators Non-experts can read it Make it familiar
- 13. Internal DSL: BuildingBlocks Vanilla .NET F# Specific Method chaining Pipelining Enumerations Discriminated Unions Classes Records Operator Overloading Custom Operators Attributes Quotations Iterators & LINQ Computation Expressions Extension methods Functions
- 14. Building a DSLfor: Detecting Price Patterns
- 15.
- 16.
- 17.
- 18. Doman-specific language approach Primitiveclassifiers Declining price Rising price Combinators for classifiers Average using regression Sequence multiple patterns Check patterns at the same time
- 19. Demo: Detecting pricepatterns Building complex from simple Check multiple conditions let bothAnd a b = both a b |> map (fun (a, b) -> a && b) Calculate minimum value let minimum = reduce min |> map (fun v -> Math.Round(v, 2)) All values are in a range let inRange min max = bothAnd (atLeast min) (atMost max)
- 20. How does itwork? What is a classifier? type Classifier<'T> = ClassifyFunc of ((DateTime * float)[] -> 'T) A function value! Given data, calculate the result Generic – can produce any value Abstract – representation is hidden
- 21. Demo: Detecting morepatterns Double bottom pattern Change over regression Down–Up two times Declining fast pattern Declining over regression (Max – Min) > 3 USD
- 22. Advanced Techniques forEmbedded DSLs
- 23. Advanced Embedded DSLs Computationexpressions Reinterpret expression composition Add constructs with F# 3.0 queries Meta-programming with quotations Reinterpret F# expressions Active patterns More expressive pattern language Implementing external DSLs
- 24. Repeating patterns inDSLs Repeating functions in DSLs Map: transform the produced value ('T -> 'R) -> Clsif<'T> -> Clsif<'R> Bind & return: composition of computations ('T -> Clsif<'R>) -> Clsif<'T> -> Clsif<'R> 'T -> Clsif<'T> Simplify using them? With language syntax?
- 25. F# computation expressions Syntaxfor computations For types with certain operations Aka monads in Haskell Declining fast pattern classify { let! max = P.maximum let! min = P.minimum let! upwards = P.regression P.rising return upwards & (abs (min - max) > 3.0) }
- 26. F# query expressions Customizethe meaning of a query event { for e in frm.MouseDown do pairwise into (e1, e2) select (e1.X - e2.X, e1.Y - e2.Y) into r iter (printfn "%A" r) } Query for event processing Custom operators e.g. iter, select, pairwise Transformations, joins, merging and more Full power to be explored!
- 27. F# active patterns Extendingthe pattern language match input with | Bracketed '*' '*' (body, rest) -> (...) | Bracketed '[' ']' (body, Bracketed '(' ')' (link, rest)) -> (...) | _ -> (...) Parsing Markdown format Detecting character patterns Detecting multi-line patterns See more at http://manning.com/petricek2
- 28.
- 29. How To: Buildingyour own DSL ❶ Understand Primitives and Combinators ❷ Model the language using Discriminated Unions ❸ Add convenient Syntax
- 30. For more information… Learnand explore F# Read tutorials at http://tryfsharp.org Join & help with F# Foundation Visit http://fsharp.org and for on GitHub! New York F# Trainings & Tutorials in May Check out: http://functional-programming.net Contact me directly: tomas@tomasp.net
Editor's Notes
- #13 Prefer internal DSLs