1 Common LISP An short introduction on most interesting parts On Principles of Programming Languages Chun Tian (binghe) 

2 CONTENTS HISTORY The History of LISP. . . . . . . . . . . . . . . . . . . . . . . . 3 LANGUAGE OVERVIEW LISP Features . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Common Lisp Features . . . . . . . . . . . . . . . . . . . . 4 EXAMPLE: A FACTORIAL FUNCTION PROGRAMMING PARADIGMS Multi-Paradigms . . . . . . . . . . . . . . . . . . . . . . . . . 6 DATA TYPES IN COMMON LISP Data Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Forms and Functions . . . . . . . . . . . . . . . . . . . . . . 8 PROGRAM STRUCTURE LIST PROCESSING Functions on Lists . . . . . . . . . . . . . . . . . . . . . . . . 9 Map/Reduce: a sample use . . . . . . . . . . . . . . . . . 10 SEQUENCE OPERATIONS The CLOS Approaches . . . . . . . . . . . . . . . . . . . . 11 COMMON LISP OBJECT SYSTEM CLOS, PART I COMMON LISP OBJECT SYSTEM CLOS, PART II COMMON LISP CONDITION SYSTEM MAINTENANCE OF LISP IMAGE RUNTIME SYSTEM CL IMPLEMENTATIONS Common Lisp Implementations (not all!) . . . . . . . . 16 REFERENCES Books . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Papers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

3 The History of LISP . LISP 1 on IBM 704: 1958-1959 . Lisp 1.5 to PDP-6 Lisp: 1960-1965 . MacLisp and InterLisp (late 1960’s - early 1980’s) . The Early 1970’s: various Lisp systems . Lisp Machines: 1973-1980 . Scheme: 1975-1980 . Prelude to Common Lisp (CLTL1): 1980-1984 . Standards Development (CLTL2): 1984-1990 . Modern commercial platforms: 1987-1999 . Modern open source platforms: 1999-2009 . QuickLisp and 3rd-party libraries: 2009-2012 HISTORY FORTRAN = FORmula TRANslator LISP = LISt Process 

4 LISP Features . Fully interactive user interface. . Dynamic linking. . Built-in dynamic storage manage- ment. . Built-in facilities for manipulating lists and symbolic names. . Standard internal representation of programs as list data. . Powerful macro facility. . Extensive runtime environment. . Minimal syntax (as compared with ALGOL-like languages). . Typeless variables. LANGUAGE OVERVIEW Common Lisp Features . Fully lexically scoped variables. . A rich set of numberical data types. . A rich set of numerical primitives. . A string data type. . Arrays and vectors. . Bit and field manipulation. . Dynamic non-local exits, and user-controllable error handling. . Built-in hash facility. . User-defined data types. . Stream-based I/O with a relatively implementation- independent interface. . Formatting and pretty-printing utilities. 

5 Example: a factorial function in C LQWIDFWLQWQ^ LQWVRIDU  ZKLOHQ!VRIDU Q UHWXUQVRIDU ` Common Lisp (version 1) GHIXQIDFWQ OHWVRIDU ORRSZKLOH!QGR VHWTVRIDU VRIDUQ GHFIQ VRIDU Common Lisp (version 2) GHIXQIDFW[ LI [   [IDFW[ EXAMPLE: A FACTORIAL FUNCTION Common Lisp (version 3) GHIXQIDFW[ ODEHOVLWHUQDFF LI Q DFF LWHUQ QDFF LWHU[ Common Lisp (version 4) GHIXQIDFW[ GHFODUHRSWLPL]HVSHHG ODEHOVLWHUQDFF GHFODUHW\SHଘ[QXPQDFF LI Q DFF LWHUWKHଘ[QXPQ WKHଘ[QXP QDFF LWHU[ 

6 Multi-Paradigms . Imperative Programming (for, if, goto, ...) . Functional Programming (lambda) . Object-oriented programming (CLOS & MOP) . Generic programming (macro) . Aspect-oriented programming (AspectL) . Rule-based and Logic progamming (Knowledge- Works & Common Prolog) PROGRAMMING PARADIGMS GOTO in C LQWIDFWLQWQ^ LQWVRIDU  D VRIDU Q LIQ!JRWRD UHWXUQVRIDU ` GOTO in Common Lisp GHIXQIDFWQ OHWVRIDU WDJERG\ D VHWTVRIDU VRIDUQ GHFIQ LI!QJRD VRIDU 

7 DATA TYPES IN COMMON LISP Data Types . Numbers . Characters . Symbols . Lists . Arrays . Hash tables . Readtables . Packages . Pathnames . Streams . Random-states . Structures . Functions . Conditions . Classes . Methods . Generic Functions number complex real rational float integer fixnum bignum signed-byte unsigned-byte bit short-float single-float double-float long-float ratio sequence list cons null (nil) vector string bit-vector data type = creation + operation array 

8 PROGRAM STRUCTURE Forms and Functions . Forms: (+ 3 4) . Self-Evaluating Forms: numbers, charac- ters, strings and bit-vectors. . Variables . Special Forms . Macros . Function calls . Named Functions: defun . Lambda-Expressions ODPEGDDEDE ! 

9 LIST PROCESSING ONE TWO THREE (ONE TWO THREE) (ONE . TWO) = (cons ‘one ‘two) Functions on Lists GHIXQJRRGUHYHUVHOVW ODEHOVUHYOVWDFF LIQXOOOVW DFF UHYFGUOLVW FRQVFDUOVWDFF UHYOVWQLO !VHWTOVW DEF $%& !JRRGUHYHUVHOVW &%$ !OVW $%& 

10 SEQUENCE OPERATIONS Map/Reduce: a sample use 7DUJHWD  D  D  D Q  " GHIXQVTXDUHVXPVHT ODEHOVVTXDUH[ [[ UHGXFH  PDS OLVW VTXDUHVHT !VHWTD   !VTXDUHVXPD  !VHWTD  !VTXDUHVXPD  4XHVWLRQD  D  D  D Q  " Another version GHIXQVTXDUHVXPVHT UHGXFH  PDS OLVW ODPEGD[ [[VHT 

11 COMMON LISP OBJECT SYSTEM CLOS, PART I The CLOS Approaches . The Layered Approach . The Generic Function Approach . The Multiple Inheritance Approach . The Method Combination Approach . First-Class Objects 7KHÀUVWOHYHORIWKH2EMHFW6\VWHPSURYLGHVDSURJUDPPDWLF LQWHUIDFHWRREMHFWRULHQWHGSURJUDPPLQJ7KLVOHYHOLVGHVLJQHGWR PHHWWKHQHHGVRIPRVWVHULRXVXVHUVDQGWRSURYLGHDV\QWD[WKDW LVFULVSDQGXQGHUVWDQGDEOH7KHVHFRQGOHYHOSURYLGHVDIXQFWLRQDO LQWHUIDFHLQWRWKHKHDUWRIWKH2EMHFW6\VWHP7KLVOHYHOLVLQWHQGHG IRUWKHSURJUDPPHUZKRLVZULWLQJYHU\FRPSOH[VRIWZDUHRUD SURJUDPPLQJHQYLURQPHQW7KHÀUVWOHYHOLVZULWWHQLQWHUPVRIWKLV VHFRQGOHYHO7KHWKLUGOHYHOSURYLGHVWKHWRROVIRUWKHSURJUDPPHU ZKRLVZULWLQJKLVRZQREMHFWRULHQWHGODQJXDJH,WDOORZVDFFHVV WRWKHSULPLWLYHREMHFWVDQGRSHUDWRUVRIWKH2EMHFW6\VWHP,WLV WKLVOHYHORQZKLFKWKHLPSOHPHQWDWLRQRIWKH2EMHFW6\VWHPLWVHOI LVEDVHG 7KH&RPPRQ/LVS2EMHFW6\VWHPLVEDVHGRQJHQHULFIXQFWLRQV UDWKHUWKDQRQPHVVDJHSDVVLQJ7KLVFKRLFHLVPDGHIRUWZR UHDVRQVWKHUHDUHVRPHSUREOHPVZLWKPHVVDJHSDVVLQJLQRS HUDWLRQVRIPRUHWKDQRQHDUJXPHQWWKHFRQFHSWRIJHQHULFIXQF WLRQVLVDJHQHUDOL]DWLRQRIWKHFRQFHSWRIRUGLQDU\/LVSIXQFWLRQV *HQHULFIXQFWLRQVDUHÀUVWFODVVREMHFWVLQWKH2EMHFW6\VWHP7KH\ FDQEHXVHGLQWKHVDPHZD\VWKDWRUGLQDU\IXQFWLRQVFDQEHXVHG LQ&RPPRQ/LVS$JHQHULFIXQFWLRQLVDWUXHIXQFWLRQWKDWFDQEH SDVVHGDVDQDUJXPHQWXVHGDVWKHÀUVWDUJXPHQWWRIXQFDOODQGDS SO\DQGVWRUHGLQWKHIXQFWLRQFHOORIDV\PERO2UGLQDU\IXQFWLRQV DQGJHQHULFIXQFWLRQVDUHFDOOHGZLWKLGHQWLFDOV\QWD[ 

12 COMMON LISP OBJECT SYSTEM CLOS, PART II Multimethods VS. Method Overloading SXEOLFFODVV$^ SXEOLFYRLGIRR$D^6\VWHPRXWSULQWOQ$$` SXEOLFYRLGIRR%E^6\VWHPRXWSULQWOQ$%` ` SXEOLFFODVV%H[WHQGV$^ SXEOLFYRLGIRR$D^6\VWHPRXWSULQWOQ%$` SXEOLFYRLGIRR%E^6\VWHPRXWSULQWOQ%%` ` SXEOLFFODVV0DLQ^ SXEOLFVWDWLFYRLGPDLQ6WULQJ>@DUJY^ $REM DUJY>@HTXDOV$"QHZ$QHZ% REMIRRREM ` ` MDYDFRPJLJDPRQNH\V0DLQ$ $$ MDYDFRPJLJDPRQNH\V0DLQ% %$ CLOS Demo Code GHIFODVVD GHIFODVVED GHIJHQHULFIRRDE GHIPHWKRGIRRDDDD$$ GHIPHWKRGIRRDDEE$% GHIPHWKRGIRREEDD%$ GHIPHWKRGIRREEEE%% !GHIYDUDPDNHLQVWDQFH D !GHIYDUEPDNHLQVWDQFH E !IRRDD $$ !IRREE %% !IRRDE $% !IRRED %$ 

13 COMMON LISP CONDITION SYSTEM Java-style exception handling WU\^ GR6WXII GR0RUH6WXII `FDWFK6RPH([FHSWLRQVH^ UHFRYHUVH ` or this in Python: WU\ GR6WXII GR0RUH6WXII H[FHSW6RPH([FHSWLRQVH UHFRYHUVH In Common Lisp you'd write this: KDQGOHUFDVH SURJQ GRVWXII GRPRUHVWXII VRPHH[FHSWLRQVH UHFRYHUVH Restart GHIXQIRRQ UHVWDUWFDVHQ XVHYDOXH[[ !IRR  !IRR (UURU'LYLVLRQE\]HURFDXVHGE\RI FRQWLQXH5HWXUQDYDOXHWRXVH 6XSSO\QHZDUJXPHQWVWRXVH 86(9$/8( DERUW5HWXUQWROHYHO 5HWXUQWRWRSORRSOHYHO !KDQGOHUELQGGLYLVLRQE\]HUR  ODPEGDLJQRUHXVHYDOXH IRR  

14 MAINTENANCE OF LISP IMAGE . Redefine variables: defvar v.s. defparameter . Redefine functions . Redefine macros . Delete unused objects . Change the classes of instances . Upgrade instaces for redefined class A example Suppose a class definition of triangle: GHIFODVVWULDQJOHVKDSH DUHDGHUVLGHDLQLWDUJVLGHD EUHDGHUVLGHELQLWDUJVLGHE FUHDGHUVLGHFLQLWDUJVLGHF was changed to: GHIFODVVWULDQJOHVKDSH DUHDGHUVLGHDLQLWDUJVLGHD EUHDGHUVLGHELQLWDUJVLGHE DQJOH&UHDGHUDQJOH&LQLWDUJDQJOH& GHIPHWKRGXSGDWHLQVWDQFHIRUUHGHଘQHGFODVVDIWHU LQVWDQFHWULDQJOH DGGHGVORWVGLVFDUGHGVORWV SOLVW UHVWLQLWDUJV GHFODUHLJQRUHLQLWDUJV LIDQGPHPEHU FGLVFDUGHGVORWV PHPEHU DQJOH&DGGHGVORWV VHWIVORWYDOXHLQVWDQFH DQJOH& WKUHHVLGHVWRDQJOH JHWISOLVW F VLGHDLQVWDQFH VLGHELQVWDQFH GHIPHWKRGVLGHFWULWULDQJOH WKLUGVLGHVLGHDWUL VLGHEWUL DQJOH&WUL $OJRULWKPLVFA DAEADEFRV& GHIXQWKLUGVLGHDEDQJOH& VTUWH[SWD H[SWE  DEFRVDQJOH& 

15 RUNTIME SYSTEM . Lisp application = System code + User code . Lisp image can be dumped into executions . Unused system code can be stripped out for saving application file size (optional) . Building process of Common Lisp systems: Bootstrap (mostly) 

16 CL IMPLEMENTATIONS Common Lisp Implementations (not all!) NAME COMPILER SUPPORTING PLATFORMS ARCHITECTURE AVG. COST CMUCL Bytecode & Native Linux, Mac OS X, Solaris, FreeBSD, NetBSD Intel x86, SPARC Free SBCL Native Linux, Mac OS X, Solaris, FreeBSD, NetBSD, OpenBSD, Windows Intel x86, AMD64, PPC, SPARC, Alpha, MIPSbe, MIPEle Free CLISP Bytecode (old), Native Windows and all UNIX-like systems Most architectures Free ECL Native via C, also byte- code Linux, FreeBSD, NetBSD, OpenBSD, Solaris, Windows, Mac OS X, iOS Most architectures Free ABCL JVM Bytecode All platforms with JDK JDK supported architectures Free CLOZURE CL Native Mac OS X, Linux, FreeBSD, Solaris, Android, Windows Intel x86, AMD64, PPC, PPC64 Free MCL Native Mac OS 9, Mac OS X PPC Free since version 5.2 ALLEGRO CL Native Linux, Mac OS X, Windows, FreeBSD, Solaris Intel x86, AMD64, SPARC $599+ LISPWORKS Native Windows, Mac OS X, Linux, Solaris, AIX, HP-UX Intel x86, AMD64, PPC, PPC64, PA-RISC $1500 (pro), $5000 (ent) LIQUID CL Native Solaris, UP-UX, AIX SPARC, PA-RISC, IBM RS/6000 Unknown SCIENEER CL Native Linux, Solaris, HP-UX Intel x86, AMD64, SPARC, IA64, PA-RISC $299+ CORMAN LISP Native Windows Intel x86 $99 GCL Native via C Windows, Linux Most architectures Free XCL Native Windows, Linux, FreeBSD Intel x86, AMD64 Free 

17 Books . Common Lisp: The Language, 2nd Edi- tion . Practical Common Lisp . On Lisp: Advanced Techniques for Com- mon LISP . Paradigms of Artificial Intelligence: Case study in Common Lisp . COMMON LISP: An Interactive Approach . Common LISP: a gentle introduction to symbolic computation . Object-Oriented Programming in Com- mon Lisp: A Programmer's Guide to CLOS . The Art of the Metaobject Protocol REFERENCES Papers . Recursive Functions of Symbolic Expressions and their Computation by Machine, Part I, by John McCarthy . History of LISP, by JohnMcCarthy . The Evolution of Lisp, by Guy L. Steele Jr. etc. . The Common Lisp Object System: An Over- view, by Linda G. DeMichiel . SBCL: a Sanely-Bootstrappable Common Lisp, by Christophe Rhodes Links . Common Lisp HyperSpec: http://www.lispworks.com/documentation/ HyperSpec/Front/index.htm