Lisp in Small Pieces

ThisisacomprehensiveaccountofthesemanticsandtheimplementationofthewholeLispfamilyoflanguages,namelyLisp,Schemeandrelateddialects.Itdescribes11interpretersand2compilers,includingveryrecenttechniquesofinterpretationandcompilation.Thebookisintwoparts.Thefirststartsfromasimpleevaluationfunctionandenrichesitwithmultiplenamespaces,continuationsandside-effectswithcommentedvariants,whileatthesametimethelanguageusedtodefinethesefeaturesisreducedtoasimplelambda-calculus.Denotationalsemanticsisthennaturallyintroduced.Thesecondpartfocusesmoreonimplementationtechniquesanddiscussesprecompilationforfastinterpretation:threadedcodeorbytecode;compilationtowardsC.Someextensionsarealsodescribedsuchasdynamicevaluation,reflection,macrosandobjects.ThiswillbecomethenewstandardreferenceforpeoplewantingtoknowmoreabouttheLispfamilyoflanguages:howtheywork,howtheyareimplemented,whattheirvariantsareandwhysuchvariantsexist.Thefullcodeissupplied(andalsoavailableovertheNet).Alargebibliographyisgivenaswellasaconsiderablenumberofexercises.ThusitmayalsobeusedbystudentstoaccompanysecondcoursesonLisporScheme.