diff --git a/wholenumber/errors.go b/wholenumber/errors.go new file mode 100644 index 0000000..4b65240 --- /dev/null +++ b/wholenumber/errors.go @@ -0,0 +1,19 @@ +package rfc8259wholenumber + +import ( + "sourcecode.social/reiver/go-erorr" +) + +const ( + errNilDestination = erorr.Error("rfc8259: nil destination") + errNilRuneScanner = erorr.Error("rfc8259: nil rune-scanner") + errUnexpectedEndOfFile = erorr.Error("rfc8259: unexpected end-of-file") +) + +func errProblemReadingRune(err error) error { + return erorr.Errorf("rfc8259: the JSON parser had a problem — problem reading rune: %w", err) +} + +func errProblemUnreadingRune(err error, r rune) error { + return erorr.Errorf("rfc8259: the JSON parser had an internal-error — problem unreading rune %q (%U): %w", r, r, err) +} diff --git a/wholenumber/parse.go b/wholenumber/parse.go new file mode 100644 index 0000000..33dd2e2 --- /dev/null +++ b/wholenumber/parse.go @@ -0,0 +1,104 @@ +package rfc8259wholenumber + +import ( + "io" + + "sourcecode.social/reiver/go-erorr" +) + +// Parse tries to parse the JSON whole-number literal. +// If it succeeds, then it return nil. +// If it failed, it returns an error. +// +// IETF RFC-8259 calls a whole number an "int" with this definition: +// +// digit1-9 = %x31-39 ; 1-9 +// +// int = zero / ( digit1-9 *DIGIT ) +// +// zero = %x30 ; 0 +// +// To avoid confusion, rather than calling this "Int" as IETF RFC-8259 does (as in other contexts +// often "int" and "integer" include negative numbers) we call this "WholeNumber". +// +// Example usage: +// +// var runescanner io.RuneScanner +// +// // ... +// +// var dst rfc8259wholenumber.WholeNumber +// err := rfc8259wholenumber.Parse(runescanner, &dst) +// +// if nil != err { +// return err +// } +// +// fmt.Printf("dst = %#v\n", dst) +func Parse(runescanner io.RuneScanner, dst *WholeNumber) error { + if nil == runescanner { + return errNilRuneScanner + } + if nil == dst { + return errNilDestination + } + + var buffer [256]byte + var p []byte = buffer[0:0] + + { + var r rune + { + var err error + + r, _, err = runescanner.ReadRune() + if nil != err { + if io.EOF == err { + return errUnexpectedEndOfFile + } + return errProblemReadingRune(err) + } + } + + switch r { + case '0': + *dst = Zero() + return nil + case '1','2','3','4','5','6','7','8','9': + p = append(p, string(r)...) + default: + return erorr.Errorf("rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was %q (%U)", r, r) + } + } + + + loop: for { + var r rune + { + var err error + + r, _, err = runescanner.ReadRune() + if nil != err && io.EOF != err { + return errProblemReadingRune(err) + } + if io.EOF == err { + /////////////////////// BREAK + break loop + } + + switch r { + case '0','1','2','3','4','5','6','7','8','9': + p = append(p, string(r)...) + default: + if err := runescanner.UnreadRune(); nil != err { + return errProblemUnreadingRune(err, r) + } + /////////////////////// BREAK + break loop + } + } + } + + *dst = Something(string(p)) + return nil +} diff --git a/wholenumber/parse_test.go b/wholenumber/parse_test.go new file mode 100644 index 0000000..f2e1ef0 --- /dev/null +++ b/wholenumber/parse_test.go @@ -0,0 +1,372 @@ +package rfc8259wholenumber_test + +import ( + "testing" + + "bytes" + "io" + + "sourcecode.social/reiver/go-utf8" + + "sourcecode.social/reiver/go-rfc8259/wholenumber" +) + +func TestParse_success(t *testing.T) { + + tests := []struct{ + Value []byte + Expected rfc8259wholenumber.WholeNumber + }{ + { + Value: []byte("0"), + Expected: rfc8259wholenumber.Zero(), + }, + { + Value: []byte("1"), + Expected: rfc8259wholenumber.One(), + }, + { + Value: []byte("2"), + Expected: rfc8259wholenumber.Something("2"), + }, + { + Value: []byte("3"), + Expected: rfc8259wholenumber.Something("3"), + }, + { + Value: []byte("4"), + Expected: rfc8259wholenumber.Something("4"), + }, + { + Value: []byte("5"), + Expected: rfc8259wholenumber.Something("5"), + }, + { + Value: []byte("6"), + Expected: rfc8259wholenumber.Something("6"), + }, + { + Value: []byte("7"), + Expected: rfc8259wholenumber.Something("7"), + }, + { + Value: []byte("8"), + Expected: rfc8259wholenumber.Something("8"), + }, + { + Value: []byte("9"), + Expected: rfc8259wholenumber.Something("9"), + }, + { + Value: []byte("10"), + Expected: rfc8259wholenumber.Something("10"), + }, + { + Value: []byte("11"), + Expected: rfc8259wholenumber.Something("11"), + }, + + + + { + Value: []byte("127"), + Expected: rfc8259wholenumber.Something("127"), + }, + + + + { + Value: []byte("7867"), + Expected: rfc8259wholenumber.Something("7867"), + }, + + + + { + Value: []byte("7873"), + Expected: rfc8259wholenumber.Something("7873"), + }, + + + + { + Value: []byte("7877"), + Expected: rfc8259wholenumber.Something("7877"), + }, + + + + { + Value: []byte("7879"), + Expected: rfc8259wholenumber.Something("7879"), + }, + + + + { + Value: []byte("7883"), + Expected: rfc8259wholenumber.Something("7883"), + }, + + + + { + Value: []byte("7901"), + Expected: rfc8259wholenumber.Something("7901"), + }, + + + + { + Value: []byte("7907"), + Expected: rfc8259wholenumber.Something("7907"), + }, + + + + { + Value: []byte("7919"), + Expected: rfc8259wholenumber.Something("7919"), + }, + + + + { + Value: []byte("999331"), + Expected: rfc8259wholenumber.Something("999331"), + }, + + + + { + Value: []byte("8683317618811886495518194401279999999"), + Expected: rfc8259wholenumber.Something("8683317618811886495518194401279999999"), + }, + + + + { + Value: []byte("13256278887989457651018865901401704640"), + Expected: rfc8259wholenumber.Something("13256278887989457651018865901401704640"), + }, + + + + { + Value: []byte("123.45"), + Expected: rfc8259wholenumber.Something("123"), + }, + { + Value: []byte("123 "), + Expected: rfc8259wholenumber.Something("123"), + }, + { + Value: []byte("123,"), + Expected: rfc8259wholenumber.Something("123"), + }, + { + Value: []byte("123e"), + Expected: rfc8259wholenumber.Something("123"), + }, + { + Value: []byte("123E"), + Expected: rfc8259wholenumber.Something("123"), + }, + } + + for testNumber, test := range tests { + + var reader io.Reader = bytes.NewReader(test.Value) + var runescanner io.RuneScanner = utf8.NewRuneScanner(reader) + + var actual rfc8259wholenumber.WholeNumber + err := rfc8259wholenumber.Parse(runescanner, &actual) + + if nil != err { + t.Errorf("For test #%d, did not expect to get an error but actually got one.", testNumber) + t.Logf("ERROR: (%T) %s", err, err) + t.Logf("VALUE: %q", test.Value) + t.Logf("VALUE: %#v", test.Value) + t.Logf("EXPECTED: %#v", test.Expected) + continue + } + + { + expected := test.Expected + + if expected != actual { + t.Errorf("For test #%d, the actual value is not what was expected.", testNumber) + t.Logf("EXPECTED: %#v", expected) + t.Logf("ACTUAL: %#v", actual) + t.Logf("VALUE: %q", test.Value) + t.Logf("VALUE: %#v", test.Value) + continue + } + } + } +} + +func TestParse_failure(t *testing.T) { + + tests := []struct{ + Value []byte + ExpectedError string + }{ + { + Value: []byte(nil), + ExpectedError: "rfc8259: unexpected end-of-file", + }, + { + Value: []byte(""), + ExpectedError: "rfc8259: unexpected end-of-file", + }, + + + + { + Value: []byte("\t"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was '\t' (U+0009)`, + }, + { + Value: []byte("\n"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was '\n' (U+000A)`, + }, + { + Value: []byte("\r"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was '\r' (U+000D)`, + }, + { + Value: []byte(" "), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was ' ' (U+0020)`, + }, + { + Value: []byte("\""), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was '"' (U+0022)`, + }, + { + Value: []byte("-"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was '-' (U+002D)`, + }, + { + Value: []byte("f"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was 'f' (U+0066)`, + }, + { + Value: []byte("n"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was 'n' (U+006E)`, + }, + { + Value: []byte("t"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was 't' (U+0074)`, + }, + + + + { + Value: []byte("false"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was 'f' (U+0066)`, + }, + { + Value: []byte("null"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was 'n' (U+006E)`, + }, + { + Value: []byte("true"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was 't' (U+0074)`, + }, + + + + { + Value: []byte("-1"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was '-' (U+002D)`, + }, + { + Value: []byte("-2"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was '-' (U+002D)`, + }, + { + Value: []byte("-3"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was '-' (U+002D)`, + }, + + + + { + Value: []byte("\"name\""), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was '"' (U+0022)`, + }, + + + + { + Value: []byte("apple"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was 'a' (U+0061)`, + }, + { + Value: []byte("banana"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was 'b' (U+0062)`, + }, + { + Value: []byte("cherry"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was 'c' (U+0063)`, + }, + + + { + Value: []byte("ONCE TWICE THRICE FOURCE"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was 'O' (U+004F)`, + }, + + + + { + Value: []byte("😈"), + ExpectedError: `rfc8259: JSON parser encountered a problem — when trying to parse a whole-number, expected the first character to be '0', '1', '2', '3', '4', '5', '6', '7', '8', ot '9', but actually was '😈' (U+1F608)`, + }, + } + + for testNumber, test := range tests { + + var reader io.Reader = bytes.NewReader(test.Value) + var runescanner io.RuneScanner = utf8.NewRuneScanner(reader) + + var actual rfc8259wholenumber.WholeNumber + err := rfc8259wholenumber.Parse(runescanner, &actual) + + if nil == err { + t.Errorf("For test #%d, expected an error but did not actually get one.", testNumber) + t.Logf("VALUE: %q", test.Value) + t.Logf("VALUE: %#v", test.Value) + t.Logf("EXPECTED-ERROR: %#v", test.ExpectedError) + continue + } + + { + expected := rfc8259wholenumber.Nothing() + + if expected != actual { + t.Errorf("For test #%d, the actual value is not what was expected.", testNumber) + t.Logf("EXPECTED: %#v", expected) + t.Logf("ACTUAL: %#v", actual) + t.Logf("VALUE: %q", test.Value) + t.Logf("VALUE: %#v", test.Value) + continue + } + } + + { + expected := test.ExpectedError + actual := err.Error() + + if expected != actual { + t.Errorf("For test #%d, the actual error value is not what was expected.", testNumber) + t.Logf("EXPECTED: %#v", expected) + t.Logf("ACTUAL: %#v", actual) + t.Logf("VALUE: %q", test.Value) + t.Logf("VALUE: %#v", test.Value) + continue + } + } + } +} diff --git a/wholenumber/wholenumber.go b/wholenumber/wholenumber.go new file mode 100644 index 0000000..db20cba --- /dev/null +++ b/wholenumber/wholenumber.go @@ -0,0 +1,52 @@ +package rfc8259wholenumber + +import ( + "fmt" + + "sourcecode.social/reiver/go-opt" +) + +// WholeNumber represents the numbers: +// 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,.... +// +// I.e., the set of positive-integers with zero. +// +// From IETF RFC-8259 WholeNumber represents the following: +// +// int = zero / ( digit1-9 *DIGIT ) +type WholeNumber struct { + opt.Optional[string] +} + +func Nothing() WholeNumber { + return WholeNumber{opt.Nothing[string]()} +} + +func Zero() WholeNumber { + return Something("0") +} + +func One() WholeNumber { + return Something("1") +} + +func Something(value string) WholeNumber { + return WholeNumber{opt.Something(value)} +} + +func (receiver WholeNumber) GoString() string { + switch receiver { + case Nothing(): + return "rfc8259wholenumber.Nothing()" + case Zero(): + return "rfc8259wholenumber.Zero()" + case One(): + return "rfc8259wholenumber.One()" + default: + value, found := receiver.Get() + if !found { + return fmt.Sprintf("--INTERNAL-ERROR--") + } + return fmt.Sprintf("rfc8259wholenumber.Something(%#v)", value) + } +}