Principles of Programming Languages

Introducesthefundamentalsofprogramminglanguageswithinformationonsuchtopicsasfunctions，records，datatypes，programmingwithlists，exceptions，objects，andtrees.，We’veknownaboutalgorithmsformillennia，butwe’veonlybeenwritingc-puterprogramsforafewdecades.Abigdi?erencebetweentheEuclideanorEratosthenesageandoursisthatsincethemiddleofthetwentiethcentury，weexpressthealgorithmsweconceiveusingformallanguages：programminglanguages.Computerscientistsarenottheonlyoneswhouseformallanguages.-tometrists，forexample，prescribeeyeglassesusingverytechnicalexpressions，??suchas“OD：-1.25(-0.50)180OS：-1.00(-0.25)180”，inwhichtheparent-sesareessential.Manysuchformallanguageshavebeencreatedthroughouthistory：musicalnotation，algebraicnotation，etc.Inparticular，suchlanguageshavelongbeenusedtocontrolmachines，suchasloomsandcathedralchimes.However，untiltheappearanceofprogramminglanguages，thoselanguageswereonlyoflimitedimportance：theywererestrictedtospecialised?eldswithonlyafewspecialistsandwrittentextsofthoselanguagesremainedrelativelyscarce.Thissituationhaschangedwiththeappearanceofprogrammingl-guages，whichhaveawiderrangeofapplicationsthantheprescriptionofe-glassesorthecontrolofaloom，areusedbylargecommunities，andhaveallowedthecreationofprogramsofmanyhundredsofthousandsoflines.