initial commits

errors.go

@@ -11,11 +11,3 @@ const (
 func errNotEOL(r rune) error {
 	return erorr.Errorf("eol: %q (%U) is not an end-of-line character", r, r)
 }
-
-func errProblemReadingRune(err error, runeNumber uint64) error {
-	return erorr.Errorf("eol: problem reading rune №%d of end-of-line sequence: %w", runeNumber, err)
-}
-
-func errProblemUnreadingRune(err error, runeNumber uint64, r rune) error {
-	return erorr.Errorf("eol: problem unreading rune №%d (%q (%U)) of end-of-line sequence: %w", runeNumber, r, r, err)
-}

notfound.go

@@ -9,6 +9,7 @@ var _ error = internalNotFoundError{}
 type internalNotFoundError struct{
 	expected rune
 	actual rune
+	characterNumber uint64
 }
 
 func (receiver internalNotFoundError) Error() string {
@@ -20,21 +21,23 @@ func (receiver internalNotFoundError) Error() string {
 	var expected rune = receiver.expected
 	var actual   rune = receiver.actual
 
+	var characterNumber uint64 = receiver.characterNumber
+
 	switch expected {
 	case lf:
-		var s string =  fmt.Sprintf(`eol: line-feed (LF) character ('\n') (U+000A) not found — instead found %q (%U)`, actual, actual)
+		var s string =  fmt.Sprintf(`eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №%d — instead found %q (%U)`, characterNumber, actual, actual)
 		p = append(p, s...)
 	case cr:
-		var s string = fmt.Sprintf(`eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found %q (%U)`, actual, actual)
+		var s string = fmt.Sprintf(`eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №%d — instead found %q (%U)`, characterNumber, actual, actual)
 		p = append(p, s...)
 	case nel:
-		var s string = fmt.Sprintf(`eol: next-line (NEL) character (U+0085) not found — instead found %q (%U)`, actual, actual)
+		var s string = fmt.Sprintf(`eol: next-line (NEL) character (U+0085) not found for end-of-line character №%d — instead found %q (%U)`, characterNumber, actual, actual)
 		p = append(p, s...)
 	case ls:
-		var s string = fmt.Sprintf(`eol: line-separator (LS) character (U+2028) not found — instead found %q (%U)`, actual, actual)
+		var s string = fmt.Sprintf(`eol: line-separator (LS) character (U+2028) not found for end-of-line character №%d — instead found %q (%U)`, characterNumber, actual, actual)
 		p = append(p, s...)
 	default:
-		var s string = fmt.Sprintf(`eol: %q character (%U) not found — instead found %q (%U)`, expected, expected, actual, actual)
+		var s string = fmt.Sprintf(`eol: %q character (%U) not found for character №%d — instead found %q (%U)`, expected, expected, characterNumber, actual, actual)
 		p = append(p, s...)
 	}
 

problemreadingrune.go

@@ -0,0 +1,30 @@
+package eol
+
+import (
+	"fmt"
+)
+
+var _ error = internalProblemReadingRuneError{}
+
+func errProblemReadingRune(err error, runeNumber uint64) error {
+	return internalProblemReadingRuneError{
+		err:err,
+		runeNumber:runeNumber,
+	}
+}
+
+type internalProblemReadingRuneError struct {
+	err error
+	runeNumber uint64
+}
+
+func (receiver internalProblemReadingRuneError) Error() string {
+	err := receiver.err
+	runeNumber := receiver.runeNumber
+
+	return fmt.Sprintf("eol: problem reading character №%d of end-of-line sequence: %s", runeNumber, err)
+}
+
+func (receiver internalProblemReadingRuneError) Unwrap() error {
+	return receiver.err
+}

problemunreadingrune.go

@@ -0,0 +1,33 @@
+package eol
+
+import (
+	"fmt"
+)
+
+var _ error = internalProblemUnreadingRuneError{}
+
+func errProblemUnreadingRune(err error, runeNumber uint64, r rune) error {
+	return internalProblemUnreadingRuneError{
+		err:err,
+		runeNumber:runeNumber,
+		r:r,
+	}
+}
+
+type internalProblemUnreadingRuneError struct {
+	err error
+	runeNumber uint64
+	r rune
+}
+
+func (receiver internalProblemUnreadingRuneError) Error() string {
+	err := receiver.err
+	runeNumber := receiver.runeNumber
+	r := receiver.r
+
+	return fmt.Sprintf("eol: problem unreading character №%d (%q (%U)) of end-of-line sequence: %s", runeNumber, r, r, err)
+}
+
+func (receiver internalProblemUnreadingRuneError) Unwrap() error {
+	return receiver.err
+}

readcr.go

@@ -5,5 +5,6 @@ import (
 )
 
 func ReadCR(runescanner io.RuneScanner) (size int, err error) {
-	return readthisrune(runescanner, cr)
+	const runeNumber = 1
+	return readthisrune(runescanner, cr, runeNumber)
 }

readcr_test.go

@@ -67,103 +67,103 @@ func TestReadCR_fail(t *testing.T) {
 	}{
 		{
 			Value: "",
-			ExpectedError: `eol: problem reading rune №1 of end-of-line sequence: EOF`,
+			ExpectedError: `eol: problem reading character №1 of end-of-line sequence: EOF`,
 		},
 
 
 
 		{
 			Value: "\n",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '\n' (U+000A)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '\n' (U+000A)`,
 		},
 		{
 			Value: "\u0085",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '\u0085' (U+0085)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '\u0085' (U+0085)`,
 		},
 		{
 			Value: "\u2028",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '\u2028' (U+2028)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '\u2028' (U+2028)`,
 		},
 
 
 
 		{
 			Value: "😈",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '😈' (U+1F608)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '😈' (U+1F608)`,
 		},
 
 
 
 		{
 			Value: "\napple banana cherry",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '\n' (U+000A)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '\n' (U+000A)`,
 		},
 		{
 			Value: "\u0085apple banana cherry",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '\u0085' (U+0085)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '\u0085' (U+0085)`,
 		},
 		{
 			Value: "\u2028apple banana cherry",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '\u2028' (U+2028)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '\u2028' (U+2028)`,
 		},
 
 
 
 		{
 			Value: "😈apple banana cherry",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '😈' (U+1F608)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '😈' (U+1F608)`,
 		},
 
 
 
 		{
 			Value: " \n",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \r",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \u0085",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \u2028",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 
 
 
 		{
 			Value: " 😈",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 
 
 
 		{
 			Value: ".\n",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\r",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\u0085",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\u2028",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 
 
 
 		{
 			Value: ".😈",
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 	}
 

readlf.go

@@ -5,5 +5,6 @@ import (
 )
 
 func ReadLF(runescanner io.RuneScanner) (size int, err error) {
-	return readthisrune(runescanner, lf)
+	const runeNumber = 1
+	return readthisrune(runescanner, lf, runeNumber)
 }

readlf_test.go

@@ -67,103 +67,103 @@ func TestReadLF_fail(t *testing.T) {
 	}{
 		{
 			Value: "",
-			ExpectedError: `eol: problem reading rune №1 of end-of-line sequence: EOF`,
+			ExpectedError: `eol: problem reading character №1 of end-of-line sequence: EOF`,
 		},
 
 
 
 		{
 			Value: "\r",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '\r' (U+000D)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '\r' (U+000D)`,
 		},
 		{
 			Value: "\u0085",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '\u0085' (U+0085)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '\u0085' (U+0085)`,
 		},
 		{
 			Value: "\u2028",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '\u2028' (U+2028)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '\u2028' (U+2028)`,
 		},
 
 
 
 		{
 			Value: "😈",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '😈' (U+1F608)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '😈' (U+1F608)`,
 		},
 
 
 
 		{
 			Value: "\rapple banana cherry",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '\r' (U+000D)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '\r' (U+000D)`,
 		},
 		{
 			Value: "\u0085apple banana cherry",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '\u0085' (U+0085)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '\u0085' (U+0085)`,
 		},
 		{
 			Value: "\u2028apple banana cherry",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '\u2028' (U+2028)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '\u2028' (U+2028)`,
 		},
 
 
 
 		{
 			Value: "😈apple banana cherry",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '😈' (U+1F608)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '😈' (U+1F608)`,
 		},
 
 
 
 		{
 			Value: " \n",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \r",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \u0085",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \u2028",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 
 
 
 		{
 			Value: " 😈",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 
 
 
 		{
 			Value: ".\n",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\r",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\u0085",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\u2028",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 
 
 
 		{
 			Value: ".😈",
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 	}
 

readls.go

@@ -5,5 +5,6 @@ import (
 )
 
 func ReadLS(runescanner io.RuneScanner) (size int, err error) {
-	return readthisrune(runescanner, ls)
+	const runeNumber = 1
+	return readthisrune(runescanner, ls, runeNumber)
 }

readls_test.go

@@ -67,103 +67,103 @@ func TestReadLS_fail(t *testing.T) {
 	}{
 		{
 			Value: "",
-			ExpectedError: `eol: problem reading rune №1 of end-of-line sequence: EOF`,
+			ExpectedError: `eol: problem reading character №1 of end-of-line sequence: EOF`,
 		},
 
 
 
 		{
 			Value: "\n",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '\n' (U+000A)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '\n' (U+000A)`,
 		},
 		{
 			Value: "\r",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '\r' (U+000D)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '\r' (U+000D)`,
 		},
 		{
 			Value: "\u0085",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '\u0085' (U+0085)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '\u0085' (U+0085)`,
 		},
 
 
 
 		{
 			Value: "😈",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '😈' (U+1F608)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '😈' (U+1F608)`,
 		},
 
 
 
 		{
 			Value: "\napple banana cherry",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '\n' (U+000A)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '\n' (U+000A)`,
 		},
 		{
 			Value: "\rapple banana cherry",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '\r' (U+000D)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '\r' (U+000D)`,
 		},
 		{
 			Value: "\u0085apple banana cherry",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '\u0085' (U+0085)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '\u0085' (U+0085)`,
 		},
 
 
 
 		{
 			Value: "😈apple banana cherry",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '😈' (U+1F608)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '😈' (U+1F608)`,
 		},
 
 
 
 		{
 			Value: " \n",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \r",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \u0085",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \u2028",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 
 
 
 		{
 			Value: " 😈",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 
 
 
 		{
 			Value: ".\n",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\r",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\u0085",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\u2028",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 
 
 
 		{
 			Value: ".😈",
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 	}
 

readnel.go

@@ -5,5 +5,6 @@ import (
 )
 
 func ReadNEL(runescanner io.RuneScanner) (size int, err error) {
-	return readthisrune(runescanner, nel)
+	const runeNumber = 1
+	return readthisrune(runescanner, nel, runeNumber)
 }

readnel_test.go

@@ -67,103 +67,103 @@ func TestReadNEL_fail(t *testing.T) {
 	}{
 		{
 			Value: "",
-			ExpectedError: `eol: problem reading rune №1 of end-of-line sequence: EOF`,
+			ExpectedError: `eol: problem reading character №1 of end-of-line sequence: EOF`,
 		},
 
 
 
 		{
 			Value: "\n",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '\n' (U+000A)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '\n' (U+000A)`,
 		},
 		{
 			Value: "\r",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '\r' (U+000D)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '\r' (U+000D)`,
 		},
 		{
 			Value: "\u2028",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '\u2028' (U+2028)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '\u2028' (U+2028)`,
 		},
 
 
 
 		{
 			Value: "😈",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '😈' (U+1F608)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '😈' (U+1F608)`,
 		},
 
 
 
 		{
 			Value: "\napple banana cherry",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '\n' (U+000A)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '\n' (U+000A)`,
 		},
 		{
 			Value: "\rapple banana cherry",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '\r' (U+000D)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '\r' (U+000D)`,
 		},
 		{
 			Value: "\u2028apple banana cherry",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '\u2028' (U+2028)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '\u2028' (U+2028)`,
 		},
 
 
 
 		{
 			Value: "😈apple banana cherry",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '😈' (U+1F608)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '😈' (U+1F608)`,
 		},
 
 
 
 		{
 			Value: " \n",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \r",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \u0085",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \u2028",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 
 
 
 		{
 			Value: " 😈",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found ' ' (U+0020)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found ' ' (U+0020)`,
 		},
 
 
 
 		{
 			Value: ".\n",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\r",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\u0085",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\u2028",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 
 
 
 		{
 			Value: ".😈",
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '.' (U+002E)`,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №1 — instead found '.' (U+002E)`,
 		},
 	}
 

readthisrune.go

@@ -4,7 +4,7 @@ import (
 	"io"
 )
 
-func readthisrune(runescanner io.RuneScanner, expected rune) (size int, err error) {
+func readthisrune(runescanner io.RuneScanner, expected rune, characterNumber uint64) (size int, err error) {
 	if nil == runescanner {
 		return 0, errNilRuneScanner
 	}
@@ -15,8 +15,7 @@ func readthisrune(runescanner io.RuneScanner, expected rune) (size int, err erro
 
 		r, size, err = runescanner.ReadRune()
 		if nil != err {
-			const runeNumber = 1
+			return size, errProblemReadingRune(err, characterNumber)
-			return size, errProblemReadingRune(err, runeNumber)
 		}
 	}
 
@@ -26,11 +25,10 @@ func readthisrune(runescanner io.RuneScanner, expected rune) (size int, err erro
 		if expected != actual {
 			err := runescanner.UnreadRune()
 			if nil != err {
-				const runeNumber = 1
+				return size, errProblemUnreadingRune(err, characterNumber, r)
-				return size, errProblemUnreadingRune(err, runeNumber, r)
 			}
 
-			return 0, internalNotFoundError{expected: expected, actual: r}
+			return 0, internalNotFoundError{expected: expected, actual: r, characterNumber:characterNumber}
 		}
 	}
 

readthisrune_test.go

@@ -5,7 +5,6 @@ import (
 
 	"io"
 	"strings"
-
 	"sourcecode.social/reiver/go-utf8"
 )
 
@@ -82,7 +81,8 @@ func TestReadThisRune(t *testing.T) {
 		var reader io.Reader = strings.NewReader(test.Value)
 		var runescanner io.RuneScanner = utf8.NewRuneScanner(reader)
 
-		actualSize, err := readthisrune(runescanner, test.Rune)
+		const runeNumber = 999
+		actualSize, err := readthisrune(runescanner, test.Rune, runeNumber)
 		if nil != err {
 			t.Errorf("For test #%d, did not expect an error but actually got one.", testNumber)
 			t.Logf("ERROR: (%T) %s", err, err)
@@ -113,27 +113,32 @@ func TestReadThisRune_fail(t *testing.T) {
 	tests := []struct{
 		Value string
 		Rune rune
+		RuneNumber uint64
 		ExpectedError string
 	}{
 		{
 			Value: "",
 			Rune:  '\n',
-			ExpectedError: `eol: problem reading rune №1 of end-of-line sequence: EOF`,
+			RuneNumber: 7,
+			ExpectedError: `eol: problem reading character №7 of end-of-line sequence: EOF`,
 		},
 		{
 			Value: "",
 			Rune:  '\r',
-			ExpectedError: `eol: problem reading rune №1 of end-of-line sequence: EOF`,
+			RuneNumber: 8,
+			ExpectedError: `eol: problem reading character №8 of end-of-line sequence: EOF`,
 		},
 		{
 			Value: "",
 			Rune:  '\u0085',
-			ExpectedError: `eol: problem reading rune №1 of end-of-line sequence: EOF`,
+			RuneNumber: 9,
+			ExpectedError: `eol: problem reading character №9 of end-of-line sequence: EOF`,
 		},
 		{
 			Value: "",
 			Rune:  '\u2028',
-			ExpectedError: `eol: problem reading rune №1 of end-of-line sequence: EOF`,
+			RuneNumber: 10,
+			ExpectedError: `eol: problem reading character №10 of end-of-line sequence: EOF`,
 		},
 
 
@@ -141,7 +146,8 @@ func TestReadThisRune_fail(t *testing.T) {
 		{
 			Value: "",
 			Rune:  '😈',
-			ExpectedError: `eol: problem reading rune №1 of end-of-line sequence: EOF`,
+			RuneNumber: 11,
+			ExpectedError: `eol: problem reading character №11 of end-of-line sequence: EOF`,
 		},
 
 
@@ -149,22 +155,26 @@ func TestReadThisRune_fail(t *testing.T) {
 		{
 			Value: " \n",
 			Rune:  '\n',
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found ' ' (U+0020)`,
+			RuneNumber: 12,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №12 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \r",
 			Rune:  '\r',
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found ' ' (U+0020)`,
+			RuneNumber: 13,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №13 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \u0085",
 			Rune:  '\u0085',
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found ' ' (U+0020)`,
+			RuneNumber: 14,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №14 — instead found ' ' (U+0020)`,
 		},
 		{
 			Value: " \u2028",
 			Rune:  '\u2028',
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found ' ' (U+0020)`,
+			RuneNumber: 15,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №15 — instead found ' ' (U+0020)`,
 		},
 
 
@@ -172,7 +182,8 @@ func TestReadThisRune_fail(t *testing.T) {
 		{
 			Value: " 😈",
 			Rune:  '😈',
-			ExpectedError: `eol: '😈' character (U+1F608) not found — instead found ' ' (U+0020)`,
+			RuneNumber: 16,
+			ExpectedError: `eol: '😈' character (U+1F608) not found for character №16 — instead found ' ' (U+0020)`,
 		},
 
 
@@ -180,22 +191,26 @@ func TestReadThisRune_fail(t *testing.T) {
 		{
 			Value: ".\n",
 			Rune:  '\n',
-			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found — instead found '.' (U+002E)`,
+			RuneNumber: 17,
+			ExpectedError: `eol: line-feed (LF) character ('\n') (U+000A) not found for end-of-line character №17 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\r",
 			Rune:  '\r',
-			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found — instead found '.' (U+002E)`,
+			RuneNumber: 18,
+			ExpectedError: `eol: carriage-return (CR) character ('\r') (U+000D) not found for end-of-line character №18 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\u0085",
 			Rune:  '\u0085',
-			ExpectedError: `eol: next-line (NEL) character (U+0085) not found — instead found '.' (U+002E)`,
+			RuneNumber: 19,
+			ExpectedError: `eol: next-line (NEL) character (U+0085) not found for end-of-line character №19 — instead found '.' (U+002E)`,
 		},
 		{
 			Value: ".\u2028",
 			Rune:  '\u2028',
-			ExpectedError: `eol: line-separator (LS) character (U+2028) not found — instead found '.' (U+002E)`,
+			RuneNumber: 20,
+			ExpectedError: `eol: line-separator (LS) character (U+2028) not found for end-of-line character №20 — instead found '.' (U+002E)`,
 		},
 
 
@@ -203,7 +218,8 @@ func TestReadThisRune_fail(t *testing.T) {
 		{
 			Value: ".😈",
 			Rune:  '😈',
-			ExpectedError: `eol: '😈' character (U+1F608) not found — instead found '.' (U+002E)`,
+			RuneNumber: 21,
+			ExpectedError: `eol: '😈' character (U+1F608) not found for character №21 — instead found '.' (U+002E)`,
 		},
 	}
 
@@ -212,7 +228,7 @@ func TestReadThisRune_fail(t *testing.T) {
 		var reader io.Reader = strings.NewReader(test.Value)
 		var runescanner io.RuneScanner = utf8.NewRuneScanner(reader)
 
-		actualSize, err := readthisrune(runescanner, test.Rune)
+		actualSize, err := readthisrune(runescanner, test.Rune, test.RuneNumber)
 		if nil == err {
 			t.Errorf("For test #%d, expected an error but did not actually get one.", testNumber)
 			t.Logf("EXPECTED-ERROR: %q", test.ExpectedError)