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Data update

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Ingy döt Net 2026-02-01 16:33:20 -08:00
parent 5150844a7d
commit 4bb20c9b71
7735 changed files with 38060 additions and 199180 deletions
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94
Task/ISBN13-check-digit/Pascal/isbn13-check-digit.pas
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@ -1,85 +1,85 @@
program ISBNChecksum(output);
const
codeIndexMaximum = 17;
ISBNIndexMinimum = 1;
ISBNIndexMaximum = 13;
ISBNIndexRange = ISBNIndexMaximum - ISBNIndexMinimum + 1;
codeIndexMaximum = 17;
ISBNIndexMinimum = 1;
ISBNIndexMaximum = 13;
ISBNIndexRange = ISBNIndexMaximum - ISBNIndexMinimum + 1;
type
code = string(codeIndexMaximum);
codeIndex = 1..codeIndexMaximum value 1;
decimalDigit = '0'..'9';
decimalValue = 0..9;
ISBNIndex = ISBNIndexMinimum..ISBNIndexMaximum;
ISBN = array[ISBNIndex] of decimalDigit;
code = string(codeIndexMaximum);
codeIndex = 1..codeIndexMaximum value 1;
decimalDigit = '0'..'9';
decimalValue = 0..9;
ISBNIndex = ISBNIndexMinimum..ISBNIndexMaximum;
ISBN = array[ISBNIndex] of decimalDigit;
{ returns the integer value represented by a character }
function numericValue(protected c: decimalDigit): decimalValue;
begin
{ in Pascal result variable bears the same name as the function }
numericValue := ord(c) - ord('0')
{ in Pascal result variable bears the same name as the function }
numericValue := ord(c) - ord('0')
end;
{ determines whether an ISBN is technically valid (checksum correct) }
function isValidISBN(protected n: ISBN): Boolean;
var
sum: 0..225 value 0;
i: ISBNIndex;
sum: 0..225 value 0;
i: ISBNIndex;
begin
{ NB: in Pascal for-loop-limits are _inclusive_ }
for i := ISBNIndexMinimum to ISBNIndexMaximum do
begin
{ alternating scale factor 3^0, 3^1 based on Boolean }
sum := sum + numericValue(n[i]) * 3 pow ord(not odd(i))
end;
isValidISBN := sum mod 10 = 0
{ NB: in Pascal for-loop-limits are _inclusive_ }
for i := ISBNIndexMinimum to ISBNIndexMaximum do
begin
{ alternating scale factor 3^0, 3^1 based on Boolean }
sum := sum + numericValue(n[i]) * 3 pow ord(not odd(i))
end;
isValidISBN := sum mod 10 = 0
end;
{ transform '978-0-387-97649-5' into '9780387976495' }
function digits(n: code): code;
var
sourceIndex, destinationIndex: codeIndex;
sourceIndex, destinationIndex: codeIndex;
begin
for sourceIndex := 1 to length(n) do
begin
if n[sourceIndex] in ['0'..'9'] then
begin
n[destinationIndex] := n[sourceIndex];
destinationIndex := destinationIndex + 1
end
end;
{ to alter a string’s length you need overwrite it completely }
digits := subStr(n, 1, destinationIndex - 1)
for sourceIndex := 1 to length(n) do
begin
if n[sourceIndex] in ['0'..'9'] then
begin
n[destinationIndex] := n[sourceIndex];
destinationIndex := destinationIndex + 1
end
end;
{ to alter a string’s length you need overwrite it completely }
digits := subStr(n, 1, destinationIndex - 1)
end;
{ data type coercion }
function asISBN(protected n: code): ISBN;
var
result: ISBN;
result: ISBN;
begin
unpack(n[1..length(n)], result, 1);
asISBN := result
unpack(n[1..length(n)], result, 1);
asISBN := result
end;
{ tells whether a string value contains a proper ISBN representation }
function isValidISBNString(protected hyphenatedForm: code): Boolean;
var
digitOnlyForm: code;
digitOnlyForm: code;
begin
digitOnlyForm := digits(hyphenatedForm);
{ The Extended Pascal `and_then` Boolean operator allows us }
{ to first check the length before invoking `isValidISBN`. }
isValidISBNString := (length(digitOnlyForm) = ISBNIndexRange)
and_then isValidISBN(asISBN(digitOnlyForm))
digitOnlyForm := digits(hyphenatedForm);
{ The Extended Pascal `and_then` Boolean operator allows us }
{ to first check the length before invoking `isValidISBN`. }
isValidISBNString := (length(digitOnlyForm) = ISBNIndexRange)
and_then isValidISBN(asISBN(digitOnlyForm))
end;
{ === MAIN ============================================================= }
begin
writeLn(isValidISBNString('978-0596528126'));
writeLn(isValidISBNString('978-0596528120'));
writeLn(isValidISBNString('978-1788399081'));
writeLn(isValidISBNString('978-1788399083'))
writeLn(isValidISBNString('978-0596528126'));
writeLn(isValidISBNString('978-0596528120'));
writeLn(isValidISBNString('978-1788399081'));
writeLn(isValidISBNString('978-1788399083'))
end.