CP/M/CPM_CDROM.iso/mbug/mbug003.arc/PASCAL.007

Text File | 1979-12-31 | 9KB | 226 lines

                    PASCAL   FOR   BASIC   PROGRAMMERS

                               Dixon Kenney

                                 PART VII

     Iε thi≤ nex⌠ par⌠ iε thσ serie≤ oµ programminτ iε Pascal¼ wσ arσ goinτ ì
t∩ writσ ß procedurσ b∙ whicΦ wσ caε adΣ aε iteφ oµ stocδ ¿ tha⌠ is¼ ß datß ì
recorΣ ⌐ t∩ thσ datß file«á  Iε doinτ this¼á wσ arσ goinτ t∩ usσ ß mask¼ s∩ ì
tha⌠á thσ operato≥ wh∩ i≤ fillinτ iε thσ informatioε wil∞ kno≈ exactl∙ wha⌠ ì
informatioε wσ wan⌠ theφ t∩ typσ in«á  Mos⌠ oµ thσ prograφ i≤ lef⌠ out¼á a≤ ì
i⌠á doesn'⌠á diffe≥á froφá thosσ iε previou≤á part≤á oµá thσá series«á  Thσ ì
function≤ anΣ procedure≤ wσ havσ useΣ beforσ arσ indicateΣ b∙ thei≥ Includσ ì
calls«á  Thσ linσ number¼ therefore¼ arσ no⌠ mean⌠ t∩ refe≥ t∩ thσ wholσ oµ ì
thσ program«  The∙ arσ therσ simpl∙ fo≥ referencσ iε thσ text.

  1áá Prograφ Inventory_3;

  3áááType
  4ááá  St3░     ╜ String[30];

  6áááVar
áá7ááá  Heade≥     ║ St30;


 10ááá{$╔ EXISTS.FN├ }


 12ááá{$╔ CREATEFL.PR╧ }


 14   {$╔ FWRITE.PR╧ }

 16 ááProcedurσ FormWritσ ¿ ╚ ║ St3░ );

 18áááConst
á19ááá  TabΓ ╜ º               ';

 21áááBegin

 23ááá  ClrScr;
á24ááá  Write(º ':25);
á25ááá  Writeln(H);
á26ááá  Writeln╗ Writeln;
á27ááá  Writeln(Tabb¼ 'Par⌠ Numbe≥   ║ ');
á28ááá  Writeln(Tabb¼ 'Descriptioε   ║ ');
á29ááá  Writeln;
á30ááá  Writeln(Tabb¼ 'Cos⌠ t∩ u≤    ║ ');
á31ááá  Writeln(Tabb¼ 'Retai∞ Pricσ  ║ ');
á32ááá  Writeln;
á33ááá  Writeln(Tabb¼ 'Minimuφ Leve∞ ║ ');
á34ááá  Writeln(Tabb¼ 'Maximuφ Leve∞ ║ ');
á35ááá  Writeln;
á36ááá  Writeln(Tabb¼ 'Oε HanΣ No≈   ║ ');

 38áááEnd╗    √ Procedurσ FormWritσ }

 41   {$╔ NEWITEM.PR╧ }
è 43áááProcedurσ NewItem;

á45áááConst
á46 áá  Heade≥ ╜ º ¬ AD─ ENTR┘ T╧ MASTE╥ FIL┼ *';

á48áááVar
á49ááá  Agaiε  ║ Boolean;
á50ááá  YesN∩  ║ Char;

á52áááBegin

á54ááá  Agaiε :╜ True;

á56ááá  Assign(PartFile¼ FileName);
á57ááá  Reset(PartFile);
á58ááá  Seek(PartFile¼ FileSize(PartFile));

á60ááá  Repeat
á61ááá    FormWrite(Header);
á62ááá    WitΦ Par⌠ do
á63ááá      Begin
á64ááá        GoToXY(32¼ 4)╗ Read(PartNum);
á65ááá        GoToXY(32¼ 5)╗ Read(Description);
á66ááá        GoToXY(32¼ 7)╗ Read(Cost);
á67ááá        GoToXY(32¼ 8)╗ Read(Retail);
á68ááá        GoToXY(32,10)╗ Read(MinOH);
á69ááá        GoToXY(32,11)╗ Read(MaxReorder);
á70ááá        GoTOXY(32,13)╗ Read(CurrentOH);
á71 áá        Write(PartFile¼ Part)
á72ááá    End;

á74ááá    Writeln╗ Writeln;
á75ááá    Write('D∩ yo⌡ havσ anothe≥ par⌠ t∩ ente≥ [Y/N▌ ┐ ');
á76ááá    Read(YesNo);
á77ááá    Iµ YesN∩ iε █ 'Y'¼ 'y']
á78ááá      theε Agaiε :╜ True
á79ááá    Else
á80ááá           Agaiε :╜ False
á81ááá  Unti∞ Agaiε ╜ False;

á83ááá  Close(PartFile)

á85áááEnd╗   √ Procedurσ NewIteφ }

 87   {$╔ MENU.PR╧ }

á89áááBegin  { Main Section of the program }

á91ááá    Casσ Iteφ of
á92ááá      1║ NewItem;

á94áááEnd.


     Therσá arσ onσ o≥ tw∩ necessar∙ extrß declarations╗á wσ havσá onl∙á t∩ ì
dea∞á witΦá thσ materia∞ iε thσ tw∩ ne≈ procedures«á  Let'≤ dea∞á witΦá thσ ì
procedurσ FormWritσ first.

è     Thi≤á procedurσá exist≤ simpl∙ t∩ writσ ß datß masδ oε thσá screen«á ┴ ì
masδá i≤ ß screeε whicΦ describe≤ thσ recorΣ iε word≤ whicΦá thσá oper-ato≥ ì
caεá understand«á  "MinOHó migh⌠ bσ understooΣ b∙ thσ persoε wh∩ wrotσá thσ ì
code¼á bu⌠á ß use≥ oµ thσ prograφ woulΣ understanΣ "Minimuφ Leveló ß littlσ ì
morσá easily«á  Thσá detail≤á oµá eacΦ fielΣá oµá thσá recorΣá arσá printeΣ ì
sequentiall∙ oε thσ screen.

     Iεá linσá 16¼á thσá procedurσ header¼á ß paramete≥ i≤á passeΣá t∩á thσ ì
procedure«  I⌠ i≤ thσ Heade≥ fo≥ thσ screeε mask«  Thi≤ particula≥ masδ caε ì
bσá useΣá fo≥ morσ thaε th≤ procedure¼á sincσ i⌠ describe≤ eacΦá recorΣá iε ì
full«á  So¼á wσá pas≤ t∩ thσ procedurσ whicΦ use≤ thσ masδ thσ titlσ oµ thσ ì
mask¼á whicΦ i≤ se⌠ u≡ iε thσ callinτ procedure¼á herσ linσ 46«  B∙ passinτ ì
thi≤ header¼á mucΦ codσ writinτ i≤ saved¼á sincσ wσ d∩ no⌠ neeΣ t∩ writσá ß ì
masδ fo≥ eacΦ individua∞ procedure.

     No≈á let'≤ movσ oε t∩ thσ nex⌠ procedurσ - Procedurσá NewItem«á  Therσ ì
arσ ß numbe≥ oµ item≤ t∩ looδ a⌠ here«á  Thi≤ procedurσ i≤ calleΣ froφ linσ ì
92¼ whicΦ i≤ par⌠ oµ thσ Casσ statemen⌠ iε thσ Maiε blocδ oµ thσ program.

     Iε linσ 57¼ thσ filσ whicΦ ha≤ beeε previousl∙ createΣ i≤ opened«  Thσ ì
functioεá Rese⌠á open≤á aε alread∙ createΣ file«á  Herσ i⌠ open≤á thσá filσ ì
referreΣ t∩ b∙ thσ filσ variablσ PartFile¼ tha⌠ is¼ "INVENT.DAT"«  Wheε thσ ì
filσ i≤ opened¼á thσ recorΣ pointe≥ i≤ se⌠ t∩ poin⌠ a⌠ thσ beginninτ oµ thσ ì
file¼á tha⌠ is¼ t∩ recorΣ 0«  Thσ filσ i≤ closeΣ iε linσ 83¼ usinτ thσ samσ ì
functioε a≤ wσ useΣ iε thσ CreateFilσ proced-urσ - Close«  Iε betweeε thesσ ì
tw∩ functions¼ wσ d∩ ß lo⌠ oµ work.

     Iε linσ 58¼á wσ pu⌠ thσ recorΣ pointe≥ t∩ thσ enΣ oµ thσá file«á  Thi≤ ì
linσá contain≤ tw∩ functions«á  Thσ functioε Seek(filevariable,n)ô move≤ thσ ì
recorΣá pointe≥ througΦ thσ filσ 'filevariableº unti∞ i⌠ point≤á a⌠á recorΣ ì
numbe≥á 'n'«á  Thi≤ functioε caε bσ useΣ a⌠ an∙ timσ t∩ acces≤ ß particula≥ ì
recorΣ iµ thσ numbe≥ oµ thσ recorΣ i≤ known.

     Iεá orde≥ t∩ appenΣ ß recorΣ t∩ thσ file¼á wσ mus⌠ movσ t∩ thσ enΣá oµ ì
thσ filσ - tha⌠ is¼á t∩ thσ recorΣ nex⌠ pas⌠ thσ fina∞ recorΣ oµ thσá file«  ì
Thi≤á i≤ donσ b∙ usinτ thσ functioε FileSize(filevariable)«á  Thi≤ functioε ì
count≤ thσ numbe≥ oµ record≤ iε thσ file«á  So¼á iµ wσ haΣ ╕á records¼á thσ ì
functioε return≤ thσ numbe≥ 8«  However¼ sincσ thσ firs⌠ recorΣ i≤ numbereΣ ì
0¼ thσ fina∞ actua∞ recorΣ i≤ numbe≥ 7¼ anΣ thσ Seeδ functioε i≤ positioneΣ ì
t∩á poin⌠á t∩ thσ nex⌠ recorΣ t∩ bσ appendeΣ t∩ thσ file«á  Notσ tha⌠á thi≤ ì
functioε i≤ oµ typσ integer¼á anΣ thσ numbe≥ 'nº supplieΣ t∩ Seeδ mus⌠ als∩ ì
bσ oµ typσ Integer.

     No≈ looδ a⌠ linσ 6▓ - WIT╚ Par⌠ DO«á  Wheε wσ wan⌠ t∩ acces≤ ß record¼ ì
wσá caε finΣ ourselve≤ iε ß bi⌠ oµ trouble¼á a≤ wσ usuall∙ wan⌠ t∩ worδá oε ì
thσ individua∞ field≤ oµ eacΦ record«á  Iε Pascal¼ wσ caε referencσ eacΦ oµ ì
thσ field≤ oµ ß record≤ b∙ usinτ ß fielΣ selector«á  Thi≤ fielΣ selecto≥ i≤ ì
madσ u≡ oµ thσ recorΣ namσ followeΣ b∙ ß perioΣ followeΣ b∙ thσ fielΣ name«  ì
S∩ here¼ t∩ acces≤ eacΦ field¼ wσ woulΣ havσ t∩ say¼ fo≥ example

     Part.Partnuφ             Part.Retai∞         Part.CurrentOH

     I⌠á woulΣ bσ mucΦ easie≥ fo≥ u≤ iµ wσ werσ ablσ t∩ acces≤á eacΦá fielΣ ì
simpl∙á b∙ it≤ owε label¼á withou⌠ thσ neeΣ fo≥ thσ prefixeΣ recorΣá label«  ì
Wσ caε makσ thing≤ mucΦ shorte≥ b∙ usinτ thi≤ WIT╚ statement¼ a≤ yo⌡ seσ i⌠ ì
useΣ here«  Thσ synta° i≤ quitσ simplσ -

                 WIT╚ record_variable_labe∞ D╧ statement.
è     Thσ 'statementº par⌠ i≤ wha⌠ yo⌡ wan⌠ t∩ d∩ witΦ thσ individua∞ field≤ ì
oµá thσá recorΣá yo⌡á arσ accessing«á  I⌠ ma∙ bσ a≤á simplσá o≥á comple°á ß ì
statemen⌠á a≤á yo⌡ wish«á  Thσ WIT╚ statemen⌠ caε bσ mucΦ morσá complicateΣ ì
thaεá thi≤ - you≥ Turb∩ Pasca∞ manua∞ wil∞ sho≈ yo⌡ ho≈ iµ yo⌡á arσá reall∙ ì
interested¼ bu⌠ thi≤ i≤ complicateΣ enougΦ fo≥ u≤ now.

     Iεá line≤ 64µ (anΣ iε linσ 14╩ oµ thσ previou≤ prograφ iε par⌠ VI⌐á wσ ì
havσ ß simplσ curso≥ positioninτ statement.

áááááááááThi≤á i≤á equivalen⌠á t∩á MicroWorlΣá Basic'≤á CUR╙ ì
ááááááááástatement¼ anΣ i≤ useΣ iε mucΦ thσ samσ way¼ a≤ yo⌡ ì
ááááááááácan see.

     Thσ curso≥ i≤ moveΣ t∩ thσ positioε oε thσ screeε indicateΣ b∙ thσ tw∩ ì
intege≥á number≤ oε whicΦ thσ functioε operates«á  Thσ firs⌠ i≤ thσá columε ì
number¼á anΣ thσ seconΣ thσ row«  NB«  Thi≤ i≤ thσ reversσ oµ thσ situatioε ì
a≤ describeΣ iε thσ Manual¼ whicΦ say≤ thσ functioε i≤ row¼ column«

     Iε thi≤ function¼á thσ curso≥ i≤ positioneΣ iε turε a⌠ thσ enΣ oµ eacΦ ì
oµá thσá prompt≤á printeΣ oε thσ screeε b∙ thσ mask«á  Thi≤á prevent≤á botΦ ì
scrollinτ oµ thσ screeε anΣ overwritinτ oµ informatioε oε it.

     Iε linσ 71¼á afte≥ al∞ thσ informatioε i≤ obtained¼á wσ actuall∙ writσ ì
thσáá recorΣá t∩á disk¼áá usinτá thσá thσáá procedurσáá WRITE(filevariable¼ ì
recordvariable)«á  Thi≤ functioε differ≤ froφ mos⌠ othe≥ Pascals¼ whicΦ usσ ì
thσ procedurσ PUT«  Iµ yo⌡ arσ writinτ iε anothe≥ versioε oµ Pascal¼ havinτ ì
learn⌠ TPascal¼á theε bσ ver∙ carefu∞ oµ this¼á anΣ finΣ ou⌠ jus⌠ wha⌠ you≥ ì
ne≈ version'≤ synta° is.

     Finally¼á wσ comσ t∩ thσ concep⌠ oµ ß set¼á iε linσ 77«  Iε Pascal¼ wσ ì
arσá ablσá t∩ definσ sets¼á whicΦ thσ manua∞ describe≤ a≤ "collect-ion≤á oµ ì
relateΣá object≤ whicΦ ma∙ bσ though⌠ oµ a≤ ß whole.ó  Thσ member≤á oµá thσ ì
se⌠ ¿ eacΦ oµ it≤ individua∞ item≤ ⌐ mus⌠ bσ oµ thσ samσ type¼ whicΦ caε bσ ì
an∙ scala≥ typσ excep⌠ typσ REAL.

     Herσá wσ simpl∙ writσ ß conditiona∞ statement¼á t∩ seσ iµ thσ content≤ ì
oµ ß variablσ exis⌠ withiε ß set«á  Noticσ tha⌠ thσ member≤ oµ thσ se⌠á arσ ì
defineΣ betweeε squarσ brackets¼ eacΦ separateΣ froφ thσ other≤ b∙ ß comma¼ ì
and¼á iε thσ casσ oµ characters¼ delimiteΣ b∙ singlσ quotσ marks«   ┴ rangσ ì
oµá se⌠á member≤á caεá bσ expresseΣ b∙ separatinτ thσá lowes⌠á anΣá highes⌠ ì
element≤ oµ thσ rangσ b∙ tw∩ consecutivσ periods¼ likσ thi≤ -

                  [ 'A'..'Z' , 'a'..'z' , '0'..'9' ]

Iε thi≤ line¼ wσ arσ writinτ ß mucΦ simple≥ wa∙ oµ saying

                    If YesNo = 'Y' or YesNo = 'y'

     Yo⌡ caε seσ ho≈ mucΦ spacσ i≤ saveΣ iε ou≥ codσ iµ therσ arσ morσ thaε ì
tw∩ element≤ iε thσ se⌠ beinτ tested«

                            END OF PART SEVEN.