Little Languages

LITTLELANGUAGESLITTLELANGUAGESBYJonBentleyBYJonBentley

PRESENTEDBY:AlejandraYepezPRESENTEDBY:AlejandraYepez

MississippiStateUniversity

LANGUAGESLANGUAGESIt is a particular kind of system for encoding and It is a particular kind of system for encoding and decoding information.decoding information.

Combination of symbols in order to produce any Combination of symbols in order to produce any meaning that can be understood by a group meaning that can be understood by a group domain.domain.

Examples?Examples?


LANGUAGESLANGUAGESExamples:Examples:

Human LanguagesHuman Languages



Artificial LanguagesArtificial Languages



Artificial Languages: Artificial Languages: AdunaicAdunaic



Artificial LanguagesArtificial Languages


ProgrammingProgramming LanguagesLanguagesProgramming languages can be used to create Programming languages can be used to create programs that control the behavior of a programs that control the behavior of a machine, to express algorithms precisely, or as machine, to express algorithms precisely, or as a mode of human communicationa mode of human communication..


EvolutionoftheMajorProgrammingLanguagesEvolutionoftheMajorProgrammingLanguagesMississippiStateUniversity

RootofsomeHumanRootofsomeHuman LanguagesLanguagesNatural,preNatural,preexistinglanguagesmayalsobeusedinexistinglanguagesmayalsobeusedin

thisway;theirdevelopersmerelycataloguedandthisway;theirdevelopersmerelycataloguedand standardizedtheirvocabularyandidentifiedtheirstandardizedtheirvocabularyandidentifiedtheir grammaticalrules.grammaticalrules.

Onesuchlanguage,Onesuchlanguage,LatinoSineLatinoSineFlexioneFlexione,,

wasthewasthe basedforthedevelopmentofnewhumanlanguagesbasedforthedevelopmentofnewhumanlanguages

likeSpanish,Portuguese,French,Italian,andothers.likeSpanish,Portuguese,French,Italian,andothers.


LITTLELANGUAGESLITTLELANGUAGESAny

Mechanism

to

express

intent,

and

the

input

to

many

programsAny

Mechanism

to

express

intent,

and

the

input

to

many

programs

canbeviewedasstatementinalanguagecanbeviewedasstatementinalanguage..

Littlelanguages=computerlanguages(JonBentley,1986).Littlelanguages=computerlanguages(JonBentley,1986).

Little

languages

commonly

known

as

domainLittle

languages

commonly

known

as

domainspecific

languagesspecific

languages

((DSLsDSLs),ormicro),ormicrolanguages.languages.

DomainDomainSpecific

Language

(DSL):Specific

Language

(DSL):

A

small,

usually

declarative,A

small,

usually

declarative,

languageexpressiveoverthedistinguishingcharacteristicsofalanguageexpressiveoverthedistinguishingcharacteristicsofa

setofsetof

programsinaparticularproblemdomainprogramsinaparticularproblemdomain

(Walton,1996).(Walton,1996).

In

contrast

to

a

general

purpose

language

(GPL),

a

domainIn

contrast

to

a

general

purpose

language

(GPL),

a

domainspecificspecific

language

(DSL)

is

a

language

that

is

expressive

uniquely

over

thlanguage

(DSL)

is

a

language

that

is

expressive

uniquely

over

thee

specificfeaturesofprogramsinagivenproblemdomain.specificfeaturesofprogramsinagivenproblemdomain.


LITTLELANGUAGESLITTLELANGUAGESLittle

languages

commonly

known

as

domainLittle

languages

commonly

known

as

domainspecific

languagesspecific

languages

((DSLsDSLs),ormicro),ormicrolanguages.languages.

In

contrast

to

a

general

purpose

language

(GPL),

a

domainIn

contrast

to

a

general

purpose

language

(GPL),

a

domainspecificspecific

language

(DSL)

is

a

language

that

is

expressive

uniquely

over

thlanguage

(DSL)

is

a

language

that

is

expressive

uniquely

over

thee

specificfeaturesofprogramsinagivenproblemdomain.specificfeaturesofprogramsinagivenproblemdomain.


Someone asked: "What do little programming languages have to do with domain analysis/reuse?

Someone asked: "Currently, therere many systems that we can learn to use and master it within a short period of time but Im sure that theyre not small languages so is there any other outstanding characteristic of little language?

LITTLELANGUAGESLITTLELANGUAGESSomewidelyusedSomewidelyusedDSLsDSLs

withtheirapplicationdomains:withtheirapplicationdomains:

Someone asked: "Is the Microsoft Visual Studio a little language, since it has ways for users to point and click to put together a Windows application? Someone asked: "Are little languages common in today's market?Someone asked: "Are the principles introduced in this paper still valid these days?

Someone asked: "This is a 1986 paper when computer technology was used by pretty advanced users and scientists. However, in current globalized market, how feasible it is to develop little languages from business point of view?Someone asked: "Although the advantages of the little languages, I really double about their abilities to handling complex problems nowadays, considering such idea was proposed nearly twenty years ago and problems become much complex.

PICPICCreatedbyBrianKernighan.CreatedbyBrianKernighan.

HeisthecreatoroftheexpressionWYSIAYG,andHeisthecreatoroftheexpressionWYSIAYG,and WYSIWYG.WYSIWYG.


PICPIC

WYSIAYG:WYSIAYG:"WhatYouSeeIsAll"WhatYouSeeIsAll YouGet"YouGet"

WYSIWYG:WYSIWYG:"WhatYouSeeIs"WhatYouSeeIs WhatYouGetWhatYouGet


PICPIC Howdoweuseit?Howdoweuseit?PicPic

isadomainisadomainspecificlanguagefordrawingpictures.specificlanguagefordrawingpictures.

PicPic

providesboxes,lines,arrows,circles,ellipses,arcs,providesboxes,lines,arrows,circles,ellipses,arcs, andandsplinessplines,plusfacilitiesforpositioningandlabeling,plusfacilitiesforpositioningandlabeling

them.them.


PICPIC Howdoweuseit?Howdoweuseit?Each

picture

begins

withEach

picture

begins

with

..PS

and

ends

withand

ends

with

.PE.PE;;

betweenthemarecommandstodescribethepicture.betweenthemarecommandstodescribethepicture.

Eachcommandistypedonalinebyitself.Eachcommandistypedonalinebyitself.

PicPic

is

ais

a

trofftroff

preprocessor;

it

passes

most

of

its

inputpreprocessor;

it

passes

most

of

its

input through

untouched,

but

translates

commands

betweenthrough

untouched,

but

translates

commands

between

.PS

and

.PE

into.PS

and

.PE

into

trofftroff

commands

that

draw

thecommands

that

draw

the pictures.pictures.


PICPIC Basic!!Basic!!Forexample:Forexample:

.PS.PS

box"thisis""aboxbox"thisis""abox

.PE.PE

ResultResult


PICPIC Basic!!Basic!!

Textiscenteredonlinesandarrows;ifthereismorethanoneTextiscenteredonlinesandarrows;ifthereismorethanone lineoftext,thelinesarecenteredaboveandbelow:lineoftext,thelinesarecenteredaboveandbelow:

line"thisis""alineline"thisis""aline

arrow"thisis""anarrowarrow"thisis""anarrow

Boxesandlinesmaybedashedordotted;justaddthewordBoxesandlinesmaybedashedordotted;justaddtheword dashedordottedafterboxorline:dashedordottedafterboxorline:

linedashed"dashed""linelinedashed"dashed""line


Wecanusecircleorellipseinplaceofabox:Wecanusecircleorellipseinplaceofabox:

PICPIC Basic!!Basic!!MississippiStateUniversity

Arcsbydefaultturn90degreescounterclockwisefromtheArcsbydefaultturn90degreescounterclockwisefromthe currentdirection;youcanmakethemturnclockcurrentdirection;youcanmakethemturnclockwisebysayingwisebysaying

arcarccwcw::

lineline;arc;arc;arc;arccwcw;;arrowarrow

Whatistheshapeofarc;arc;arc;arc?


Whatistheshapeofarc;arc;arc;arc???


Objectsarenormallydrawnoneafteranother,lefttoright,andObjectsarenormallydrawnoneafteranother,lefttoright,and connectedattheobviousplaces:connectedattheobviousplaces:

arrow;arrow;

box"inputbox"input;;

arrow;arrow;

box"process";box"process";

arrow;arrow;

box"output";box"output";

Arrow;Arrow;

PICPICControllingSizes!!ControllingSizes!!MississippiStateUniversity

EachobjectthatPICknowsabout(boxes,circles,etc.)hasEachobjectthatPICknowsabout(boxes,circles,etc.)has associateddimensions,likeheight(ht),width(associateddimensions,likeheight(ht),width(widwid),radius),radius ((radrad),andsoon.),andsoon.

Forexample:Forexample:

boxwidth3height0.1;

circleradius0.1;

Box

34"wide 12"highCircle

12 diameterEllipse

34 wide 12"highArc

12 radiuslineorarrow12 longmove

12 inthecurrentdirection

PICPICControllingPositions!!ControllingPositions!!MississippiStateUniversity

Youcanplacethingsanywhereyouwant.Youcanplacethingsanywhereyouwant.

PicPic

usesastandardCartesiancoordinatesystemwithxusesastandardCartesiancoordinatesystemwithx increasingrightwardsandyincreasingupwards,soanypointincreasingrightwardsandyincreasingupwards,soanypoint

orobjecthasanxandyposition,measuredininches.orobjecthasanxandyposition,measuredininches.

PICPICControllingSizes!!ControllingSizes!!MississippiStateUniversity

EachLinesandarrowsaremosteasilydrawnbyspecifyingtheEachLinesandarrowsaremosteasilydrawnbyspecifyingthe amountofmotionfromwhereyouarerightnow,intermsofamountofmotionfromwhereyouarerightnow,intermsof

directions.directions.

Accordinglythewordsup,down,leftandrightandanoptionalAccordinglythewordsup,down,leftandrightandanoptional distancecanbeattachedtoline,arrow,andmove.distancecanbeattachedtoline,arrow,andmove.

Forexample:Forexample:

PICPIC

Labels!Labels!


ObjectscanbeObjectscanbelabelledlabelled

ornamedsothatyoucantalkaboutornamedsothatyoucantalkabout themlater.themlater.

Forexample,Forexample,

Box1:Box1:

boxbox

LetLetsdoanexercise!sdoanexercise!TheGOALisTheGOALiscreateapictureusingagivencreateapictureusingagivenPICPICss

inputinput..


Rules!Rules!Youhavesomesymbolsinthismoment!Youhavesomesymbolsinthismoment!

LetLetscreateapictureonthewallwiththesymbolsyouhave.screateapictureonthewallwiththesymbolsyouhave. ONEATATIME!ONEATATIME!

YouhavearoundYouhavearound30seconds30seconds

toputasymbolinitsrespectivetoputasymbolinitsrespective positiononthefigure.After30secondsifyouhavethepositiononthefigure.After30secondsifyouhavethe

followingsymbolandyoudidnotputit,youfollowingsymbolandyoudidnotputit,youreout!reout!

IfyoumakeamistakeyouIfyoumakeamistakeyoureout!reout!

ThepersonwhowinswillreceiveaThepersonwhowinswillreceiveagiftgift!:)!:)

LetLetsdoanexercise!sdoanexercise!LetLetss

createacreatea picturepicture

usingtheusingthe followingfollowing input:input:


.PSarrow"source""code"

LA:

box"lexical""analyzer"arrow"tokens"above

P:

box"parser"arrow"intermediate""code"

Sem:

box"semantic""checker"arrow

arrowupfromtopofLALC:

box"lexical""corrector"arrowupfromtopofP

Syn:

box"syntactic""corrector"arrowup

DMP:

box"diagnostic""message""printer"arrowrightfromrightofDMP

ST:

box"symbol""table"arrowfromLC.ne

toDMP.swarrowfromSem.nw

toDMP.searrowfromSem.top

toST.bot.PE

LetLetsdoanexercise!sdoanexercise!MississippiStateUniversity

PICPICss CompilerVsCompilerVs CompilerCompiler




LEX

PICPICss

CompilerVsCompilerCompilerVsCompiler LexicalAnalysisLexicalAnalysis


LEX

ThelexicalanalyzerbreakstheinputtextintounitscalledThelexicalanalyzerbreakstheinputtextintounitscalledtokenstokens..

WWhenapattern(onthelefthenapattern(onthelefthandside)isrecognized,theactiononhandside)isrecognized,theactionon

therightisperformed.therightisperformed.


>> return(GTreturn(GT););

Forexample,thePICinputline:Forexample,thePICinputline:linedownfromB1.SlinedownfromB1.S

WillbereturnbytheWillbereturnbythelexerlexer

usingthefollowingsequence:usingthefollowingsequence:

LINELINE

DOWNDOWN

FROMFROM

SYMBOL:B1SYMBOL:B1

SOUTHSOUTH

PIC

input

line

PICPICss



LEX

Someone asked: "LEX uses a little language for regular expressions to specify lexical analyzers. What other programs on your system employ regular expressions? How do they differ and why?


AC++sample:AC++sample:Sum=4;Sum=4;

WillbereturnbytheWillbereturnbythelexerlexer

usingthefollowingsequence:usingthefollowingsequence:

LEXEMELEXEME

TOKENTOKEN

TOKENTOKEN

##

VALUE/NAMEVALUE/NAME

SumSum

IDENTIDENT

3030

SumSum

==

ASSIGNASSIGN

55

44

INTEGERINTEGER

5858

44

;;

ENDSTATMENDSTATM

99

PICPICss




YACC

PICPICss

CompilerVsCompilerCompilerVsCompiler SyntaxAnalysisSyntaxAnalysis


YACC=YACC=YetAnotherCompilerYetAnotherCompiler

Compiler.Compiler.

PParsergenerator.arsergenerator.

TheinputhasthesameformasLEX.TheinputhasthesameformasLEX.


Primitive:Primitive:

BOXBOXattrlistattrlist {boxgen($1);}{boxgen($1);}AttrlistAttrlist::

attrlistattrattrlistattr;;

AttrAttr::

DIRDIRexprexpr

{storefattr($1,!DEF,$2);}{storefattr($1,!DEF,$2);}

PICPICss

CompilerVsCompilerCompilerVsCompiler SymbolTableSymbolTable


PICPICss

CompilerVsCompilerCompilerVsCompiler

CodeGenerationCodeGeneration


MAKE

PICPICss

CompilerVsCompilerCompilerVsCompiler MAKEMAKE


MAKE:keepingupMAKE:keepinguptotodateversionsofthefilescontainingheaderdateversionsofthefilescontainingheader

code,sourcecode,objectcode,documentation,andtestcases.code,sourcecode,objectcode,documentation,andtestcases.

PICPICss AdvantagesAdvantagesMississippiStateUniversity

LEX

YACC

MAKE

PICPICss AdvantagesAdvantagesMississippiStateUniversity

LEX

YACC

MAKE

Someone asked: "How can processors of little languages respond to linguistic errors?

Someone asked: "How can a better understanding of linguistic Insight can give you a better understanding of the tools you now use and how can it help you in programming better?

PICPICss AdvantagesAdvantagesOne

of

the

greatest

advantages

of

little

languages

is

thatOne

of

the

greatest

advantages

of

little

languages

is

that

oneprocessoroneprocessorsinputisanotherprocessorsinputisanotherprocessorsoutput.soutput.


Someone asked: "How exactly little languages like PIC support other processors output (the preprocessor concept that the paper is talking about)?

Someone asked: " All problems today can be solved using object oriented programming (at least Dr. Boggess said so). I could see the relevancy for one to make their own programming languages years ago, but why would they need to do that today?

PrinciplesandAdvantagePrinciplesandAdvantage ofLittleLanguagesofLittleLanguages

Little

languages

are

important

part

of

the

fourthLittle

languages

are

important

part

of

the

fourth

and

Fifthand

Fifth GenerationLanguagesandApplicationGenerators.GenerationLanguagesandApplicationGenerators.

Provide

an

elegant

interface

for

humans

to

control

complexProvide

an

elegant

interface

for

humans

to

control

complex programs.programs.

Itissimplertohaveaalargesystemcomposedofmodules.Itissimplertohaveaalargesystemcomposedofmodules.

It

is

better

before

designing

a

language,

carefully

study

theIt

is

better

before

designing

a

language,

carefully

study

the problemanddividinginparts.problemanddividinginparts.

A

smaller

language

is

easier

to

design,

build,

document,

andA

smaller

language

is

easier

to

design,

build,

document,

and maintain.maintain.

Littlelanguagesarecreative.Littlelanguagesarecreative.



Itissimplertohaveaalargesystemcomposedofmodules.Itissimplertohaveaalargesystemcomposedofmodules.


Someone asked: "Are the reusable components considered the Little Languages we build as programmers?

WhyisLTorDSLsoimportantWhyisLTorDSLsoimportant withintheSoftwareReusearea?withintheSoftwareReusearea?

TheyofferappropriatedomainTheyofferappropriatedomainspecificnotationsfromthestart.specificnotationsfromthestart.

TheirprimarycontributionistoenablereuseofsoftwareartifaTheirprimarycontributionistoenablereuseofsoftwareartifacts.cts.

SoftwarearchitecturesarecommonlyreusedwhenSoftwarearchitecturesarecommonlyreusedwhenDSLsDSLs

areare employed;forexample,GAL(GraphicsAdaptorlanguage).employed;forexample,GAL(GraphicsAdaptorlanguage).


Some people asked: How does "Little Languages" apply to software reuse?

Someone asked: Using/creating little languages is one way to reuse software assets (e.g. tools) to build the program but using big language also reuse some assets too so which one is better?

BibliographyBibliographySlides from Dr. Boggess class in Programming Languages.

J. Bentley, "Programming pearls: little languages", Communications of the ACM, 29(8): 711-721, August 1986, ACM Press.

M. Mernik, J. Heering, and A. M. Sloane, "When and how to develop domain-specific languages", ACM Computing Surveys, 37(4): 316-344, December 2005, ACM Press.

A. Van Deursen and P. Klint, Little Languages:LittleMaintenance?, Journal of Software Maintenance, 10(2), 1998.

B. W. Kernigham, PIC A Graphics Language for Typesetting User Manual, AT&T Bell Laboratories Murray Hill, New Jersey.

S. Thibault, R. Marlet, and C. Consel, A Domain Specific Language for Video Device Drivers: from Design to Implementation, Proceedings of the Conference on Domain-Specific Languages, Santa Barbara, California, Oct. 1997.


BibliographyBibliographyhttp://en.wikipedia.org/wiki/Programming_language

http://en.wikipedia.org/wiki/Language

http://en.wikipedia.org/wiki/Artistic_language

http://en.wikipedia.org/wiki/J._R._R._Tolkien

http://en.wikipedia.org/wiki/Adnaic

http://www.answers.com/topic/programminglanguage

http://en.wikipedia.org/wiki/Brian_Kernighan



LITTLE LANGUAGESLANGUAGESLANGUAGESLANGUAGESLANGUAGESLANGUAGESLANGUAGESProgramming LanguagesEvolution of the Major Programming LanguagesRoot of some Human LanguagesLITTLE LANGUAGESLITTLE LANGUAGESLITTLE LANGUAGESPICPICPIC How do we use it?PIC How do we use it?PIC Basic!!PIC Basic!!PIC Basic!!PIC Basic!!PIC Basic!!PIC Controlling Sizes!!PIC Controlling Positions!!PIC Controlling Sizes!!PIC Labels!Lets do an exercise!Lets do an exercise!Lets do an exercise!PICs Compiler Vs CompilerPICs Compiler Vs CompilerPICs Compiler Vs CompilerPICs Compiler Vs CompilerLexical AnalysisPICs Compiler Vs CompilerLexical AnalysisPICs Compiler Vs CompilerLexical AnalysisPICs Compiler Vs CompilerPICs Compiler Vs CompilerSyntax AnalysisPICs Compiler Vs CompilerSymbol TablePICs Compiler Vs Compiler Code Generation PICs Compiler Vs Compiler MAKE PICs AdvantagesPICs AdvantagesPICs AdvantagesPrinciples and Advantage of Little LanguagesPrinciples and Advantage of Little LanguagesPrinciples and Advantage of Little LanguagesWhy is LT or DSL so important within the Software Reuse area?BibliographyBibliographySlide Number 50

Little Languages

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