Domain-Specific Languages

Transcription

1 Domain-Specific Languages Tijs van der Storm

2 @tvdstorm #IPASpringDays

3 Some facts Robert Glass, Facts and fallacies of Software Engineering, Addison-Wesley 2003

4 Reuse?

5 Reuse?

6 Reuse?

7 Reuse? Domain Specific Languages!

8 Domain specific languages

9 Domain specific languages

10 Observations Special purpose Restricted Concise Expert usage Formalized Textual or graphic or combination

11 General purpose languages (GPLs)

12 DSLs

13 Programming Domain Programmer Code

14 Programming Domain Programmer Code

15 Programming is lossy encoding obfuscating encrypting dispersing tangling distorting

16 Time consuming

17 Change is error-prone

18 Cognitive distance?

19 Design reuse is hard

20 Design reuse

21 The problem a lot of code, low level code, characterized by lack of abstraction encoding domain knowledge and encoding design knowledge

22 Abstraction Pier and ocean Mondrian s Pier and Ocean

23 Modeling the domain domain analysis Ceci n est pas une vache

24 System families

25 Domain Specific Language formalized = notation capturing Cows variation points

26 Domain Specific Languages grammar, = template, metamodel sentence, = instance, model

27 Code generation Code generator Code

28 APT: numerical control from the 50s (!)

29 LaTeX: document preparation

30 VHDL: hardware description

31 Risla: financial products product LOAN Time to market went down from 3 months to 3 weeks. Developed at CWI declaration contract data PAMOUNT : amount %% Principal Amount STARTDATE : date %% Starting date MATURDATE : date %% Maturity data INTRATE : int-rate %% Interest rate RDMLIST := [] : cashflow-list %% List of redemptions. information PAF : cashflow-list IAF : cashflow-list %% Principal Amount Flow %% Interest Amount Flow registration %% Register one redemption. RDM(AMOUNT : amount, DATE : date)

32 Rascal module lang::daspec::syntax::datum extend lang::daspec::syntax::lexical; extend lang::daspec::syntax::expr; Developed at CWI start syntax Datum datum: "gegeven" LongName name "[" Key key "]" ":" Type type ; "{" Section* body "}" syntax Section definition: "definitie" "{" Text text explanation: "toelichting" "{" Text text algorithm: "bereken" "{" Text text "}" page: "pagina" Nat source: "bron" "{" Text text "}" condition: "conditie" Label? label Exp exp formula: "bereken" Label? label Exp exp usedby: "gebruikt" "in" {Key ","}+ keys shorthand: "alias" Id lowerbound: "minimaal" "voorkomen" Int upperbound: "maximaal" "voorkomen" Int

33 Tax-spec gegeven periode woonachtig in woonland [117300]: DDMMEEJJ { alias EPerWoonland minimaal voorkomen 0 maximaal voorkomen 1 pagina 60 definitie { De periode in het belastingjaar waarin de aangever in een land woont. } conditie Als is.gevuld([117300]<periode woonachtig in woonland>) dan is.gevuld([ ]<aangiftesoort DA..IBPV Buitenl>) conditie [ B]<periode woonachtig in woonland.begindatum> <= [ E]<periode woonachtig in woonland.einddatum> }

34 Other examples Make: software building Dot: graph visualization SQL: relational querying SWUL: Swing GUIs HTML: hypertext CLOPS: commandline options GNUPlot: plotting R: statistics CML: kernel config Lex: lexical scanning Excel: spreadheets Rascal: meta-programming...

35 DSL Implementation

36 DSL Code cow spots false color orange end cow spots true color brown end cow spots true color black end

37 Embedding new Cow().spots(false).color("orange").end(); cow spots false color orange end (cow spots #t color 'orange) cow do spots false color :orange end

38 Advantages No need to write/maintain parser Host language available if needed Use of existing tools (IDE) etc.

39 Drawbacks Restricted to host language Less static checking Fewer opportunities for optimization

40 Syntax definition Repetition Cow ::= cow Prop* end Prop ::= horns Bool spots Bool color Color Bool ::= true false Color ::= black brown literal orange alternative

41 Parser generation yacc bison Grammar Cow ::= cow Prop* end Prop ::= horns Bool spots Bool color Color Bool ::= true false Color ::= black brown orange lemon javacup antlr Rats! Parser parse.exe

42 Parsing Cow cow spots false color orange end parse Prop Prop* Prop spots Bool color Color whitespace omitted false orange

43 Abstract syntax tree (AST) Cow Cow Prop* implode spots color Prop Prop false orange spots Bool color Color false orange

44 Semantic analysis Constraint: Cow spots color check true orange

45 Code generation Cow spots color generate false orange

46 Tools Parser generators Attribute grammar systems Transformation systems Language workbenches Rascal Ensō

47 Upcoming DSL highlights Jurgen Vinju: Rascal Jeroen van den Bos: Derric Eelco Visser: Spoofax Hans Vangheluwe: evolution Tony Sloane: embedding

48 Thank you