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Uploaded byTomas Petricek
Teaching F#
The document discusses the use of F# as an introductory programming language for students with basic math knowledge, highlighting its mathematical orientation and industry relevance. It emphasizes the ease of transitioning to other programming languages and the language's applicability in graphical demonstrations and functional programming concepts. Additionally, it touches upon recursion and creating 3D graphics using F#, providing examples and links for further resources.
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Teaching F#
- 1. Teaching F#From numericalexpressions to 3D graphicsTomáš PetříčekF# enthusiast and F# book authorPhD student at University of Cambridge
- 2. Target audienceFreshman studentsBasicknowledge of math principles(Not too much – they may not like it)Earlier in high-school or later at university should be fine tooPossibly first programming courseControversial topic, but F# has many benefits
- 3. Related functional textbooks#1Emphasize theory and abstract thinking
- 4. Related functional textbooks#2Functional programming with fun demos
- 5. Why F# asa first language?Mathematically oriented languageSupplements math and theory courses Eliminates differences between studentsOpen-source with cross-platform support F# for MonoDevelop on Linux/MacPractical language with some market.NET/Mono skills are valued by industryVery easy transition to C# and other languages
- 6. Expressions in F#Firstfunctional programming steps
- 7. What F# shareswith math?Language is exact – we need to precisely say what we want to getComposition does not break things – we can mix various correct factsThings do not change – theorems will always be true, π will not change
- 8. Pythagorean theoremMath hasequations and expressionsExpressions can be evaluatedUsing F# Interactive> sqrt((pown 3.0 2) + (pown 4.0 2));;val it : float = 5.0
- 9. Introducing let declarationsand ifSolving quadratic equationsScript for solving written in F#let d = pown b 2 - 4.0 * a * c;;if d < 0.0 then "No real solution"elifd > 0.0 then "Two solutions"else "One solution";;let x1 = (-b + sqrt d) / 2.0 * alet x2 = (-b - sqrt d) / 2.0 * a;;
- 10. DEMOWorking with F#expressions
- 11. Composing graphics inF#Fun examples for students to play with
- 12. Composing graphicsExpressions thathave drawing as the resultSame concepts as mathematical expressions Basic shapesFunctions for creating new shapes> Fun.circle100.0f;;val it : Drawing = (Drawing 100x100)> Fun.fillColorColor.Goldenrod (Fun.circle 100.0f);;val it : Drawing = (Drawing 100x100)
- 13. Composing drawings usingcustom operator ($)Let declarations to reuse drawingsFun.circle200.0f $ Fun.move 0.0f 150.0f (Fun.circle 100.0f)let plus = Fun.lineStyle 2.0f Color.SteelBlue ( Fun.line -10.0f 0.0f 10.0f 0.0f $ Fun.line 0.0f -10.0f 0.0f 10.0f )let star = plus $ (Fun.rotate 45.0f plus)let bigStar = Fun.scale 2.0f 2.0f starWorking with shapes
- 14. DEMOCreating drawings usingF# expressions
- 15. Introducing recursion and3DDifficult concepts explained using graphics
- 16. Explaining recursionRecursion istricky conceptTwo types of recursions (from HTDP)Structural – follows recursive data structureFor example lists, trees, expressions etc.Such functions must terminate in F#General – arbitrary recursive callsMay not terminate (if it is not well written)For example generating fractals
- 17. General recursion forlistsNot tail-recursive list lengthEasy visualization of executionNot tail-recursive – work done on the “way back”let rec length list = match list with | [] -> 0 | head::tail -> (length tail) + 1
- 18. General recursion forlistsTail-recursive list lengthAll work done on the way “forward”This is what tail-recursive means!let rec length acc list = match list with | head::tail -> let newacc = acc + 1 in length newacc tail | [] -> acc;;
- 19.
- 20. Adding new dimensionto drawingsExpressions that define 3D objectsJust like math and 2D graphicsFun.colorColor.DarkRedFun.cone $( Fun.colorColor.Goldenrod (Fun.translate (0.0, 0.0, 1.0) Fun.cylinder) );;val it : Drawing3D = (...)> Fun.cube;;val it : Drawing3D = (...)
- 21. DEMOIntroducing general recursionusing 3D objects
- 22. Links and Q& AFunctional variations Web SiteCross-platform F# supportTeaching materials for F#, etc…http://functional-variations.netIf you’re interested in more, get in touch!http://tomasp.net | tomas@tomasp.net http://twitter.com/tomaspetricek