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Removed case-insensitive functionality from shuntingYard(); should be put in thompson() instead

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posixStyleMatching
Aadhavan Srinivasan 5 months ago
parent 94c8044eb7
commit c92b3d0e7c
1 changed files with 12 additions and 23 deletions
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35
compile.go
Unescape Escape View File

@ -74,6 +74,9 @@ func getPOSIXClass(str []rune) (bool, string) {
return true, rtv
}
// Stores whether the case-insensitive flag has been enabled.
var caseInsensitive bool
/*
The Shunting-Yard algorithm is used to convert the given infix (regeular) expression to postfix.
The primary benefit of this is getting rid of parentheses.
@ -85,7 +88,7 @@ See: https://blog.cernera.me/converting-regular-expressions-to-postfix-notation-
func shuntingYard(re string, flags ...ReFlag) ([]postfixNode, error) {
// Check which flags are enabled
caseInsensitive := false
caseInsensitive = false
// In Multiline mode, the newline character is considered a
// 'dot' character ie. the dot metacharacter matches a newline as well.
if slices.Contains(flags, RE_MULTILINE) {
@ -324,7 +327,7 @@ func shuntingYard(re string, flags ...ReFlag) ([]postfixNode, error) {
*/
c := re_postfix[i]
if isNormalChar(c) || isSpecialCharWithMetacharReplacement(c) {
outQueue = append(outQueue, newPostfixNode(allCases(c, caseInsensitive)...))
outQueue = append(outQueue, newPostfixNode(c))
continue
}
// Since every unescaped bracket is replaced by a LBRACKET / RBRACKET, there may
@ -352,7 +355,7 @@ func shuntingYard(re string, flags ...ReFlag) ([]postfixNode, error) {
if n < 1 || err != nil {
return nil, fmt.Errorf("error parsing expanded hex code in expression")
}
outQueue = append(outQueue, newPostfixCharNode(allCases(rune(hexVal), caseInsensitive)...))
outQueue = append(outQueue, newPostfixCharNode(rune(hexVal)))
i += 7
} else if i < len(re_postfix)-1 { // Two-digit hex code
hexVal, err := strconv.ParseInt(string([]rune{re_postfix[i], re_postfix[i+1]}), 16, 64) // Convert the two hex values into a rune slice, then to a string. Parse the string into an int with strconv.ParseInt()
@ -360,7 +363,7 @@ func shuntingYard(re string, flags ...ReFlag) ([]postfixNode, error) {
return nil, fmt.Errorf("error parsing hex characters in expression")
}
i++ // Loop increment will take care of going forward
outQueue = append(outQueue, newPostfixCharNode(allCases(rune(hexVal), caseInsensitive)...))
outQueue = append(outQueue, newPostfixCharNode(rune(hexVal)))
} else {
return nil, fmt.Errorf("not enough hex characters found in expression")
}
@ -380,7 +383,7 @@ func shuntingYard(re string, flags ...ReFlag) ([]postfixNode, error) {
return nil, fmt.Errorf("invalid octal value in expression")
}
i += numDigitsParsed - 1 // Shift forward by the number of digits that were parsed. Move back one character, because the loop increment will move us back to the next character automatically
outQueue = append(outQueue, newPostfixCharNode(allCases(rune(octVal), caseInsensitive)...))
outQueue = append(outQueue, newPostfixCharNode(rune(octVal)))
} else {
escapedNode, err := newEscapedNode(re_postfix[i], false)
if err != nil {
@ -520,7 +523,7 @@ func shuntingYard(re string, flags ...ReFlag) ([]postfixNode, error) {
if n < 1 || err != nil {
return nil, fmt.Errorf("error parsing expanded hex code in character class")
}
chars = append(chars, newPostfixCharNode(allCases(rune(hexVal), caseInsensitive)...))
chars = append(chars, newPostfixCharNode(rune(hexVal)))
i += 8
} else if i < len(re_postfix)-2 { // Two-digit hex code
hexVal, err := strconv.ParseInt(string([]rune{re_postfix[i], re_postfix[i+1]}), 16, 64) // Convert the two hex values into a rune slice, then to a string. Parse the string into an int with strconv.ParseInt()
@ -528,7 +531,7 @@ func shuntingYard(re string, flags ...ReFlag) ([]postfixNode, error) {
return nil, fmt.Errorf("error parsing hex characters in character class")
}
i += 2
chars = append(chars, newPostfixCharNode(allCases(rune(hexVal), caseInsensitive)...))
chars = append(chars, newPostfixCharNode(rune(hexVal)))
} else {
return nil, fmt.Errorf("not enough hex characters found in character class")
}
@ -548,7 +551,7 @@ func shuntingYard(re string, flags ...ReFlag) ([]postfixNode, error) {
return nil, fmt.Errorf("invalid octal value in character class")
}
i += numDigitsParsed // Shift forward by the number of characters parsed
chars = append(chars, newPostfixCharNode(allCases(rune(octVal), caseInsensitive)...))
chars = append(chars, newPostfixCharNode(rune(octVal)))
} else {
escapedNode, err := newEscapedNode(re_postfix[i], true)
if err != nil {
@ -577,23 +580,9 @@ func shuntingYard(re string, flags ...ReFlag) ([]postfixNode, error) {
nodeToAdd = newPostfixCharNode(genRangeInclusive('0', '9')...)
case "upper": // [A-Z]
charsToAdd := genRangeInclusive('A', 'Z')
if caseInsensitive {
// Convert each rune to a slice of runes using allCases, then flatten the resulting
// 2-D slice into a 1-D slice. Assign the result to charsToAdd.
charsToAdd = slices.Concat(Map(charsToAdd, func(r rune) []rune {
return allCases(r, caseInsensitive)
})...)
}
nodeToAdd = newPostfixCharNode(charsToAdd...)
case "lower": // [a-z]
charsToAdd := genRangeInclusive('a', 'z')
if caseInsensitive {
// Convert each rune to a slice of runes using allCases, then flatten the resulting
// 2-D slice into a 1-D slice. Assign the result to charsToAdd.
charsToAdd = slices.Concat(Map(charsToAdd, func(r rune) []rune {
return allCases(r, caseInsensitive)
})...)
}
nodeToAdd = newPostfixCharNode(charsToAdd...)
case "alpha": //[A-Za-z]
nodeToAdd = newPostfixCharNode(slices.Concat(genRangeInclusive('A', 'Z'), genRangeInclusive('a', 'z'))...)
@ -642,7 +631,7 @@ func shuntingYard(re string, flags ...ReFlag) ([]postfixNode, error) {
return nil, fmt.Errorf("error parsing high-range unicode value in character class")
}
}
chars = append(chars, newPostfixCharNode(allCases(re_postfix[i], caseInsensitive)...))
chars = append(chars, newPostfixCharNode(re_postfix[i]))
i++
}
firstCharAdded = true

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