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Regex Literals Are Never Left Bound #869

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Merged
merged 1 commit into from
Sep 30, 2022
Merged

Regex Literals Are Never Left Bound #869

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11 changes: 8 additions & 3 deletions Sources/SwiftParser/Lexer.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -783,14 +783,14 @@ extension Lexer.Cursor {
}

// Try lex a regex literal.
if let token = self.tryLexRegexLiteral(start) {
if let token = self.tryLexRegexLiteral(start, ContentStart) {
return (token, [])
}
// Otherwise try lex a magic pound literal.
return self.lexMagicPoundLiteral()
case UInt8(ascii: "/"):
// Try lex a regex literal.
if let token = self.tryLexRegexLiteral(start) {
if let token = self.tryLexRegexLiteral(start, ContentStart) {
return (token, [])
}

Expand Down Expand Up @@ -2027,8 +2027,13 @@ extension Lexer.Cursor {

extension Lexer.Cursor {
mutating func tryLexRegexLiteral(
_ TokStart: Lexer.Cursor
_ TokStart: Lexer.Cursor,
_ ContentStart: Lexer.Cursor
) -> RawTokenKind? {
guard !TokStart.isLeftBound(ContentStart) else {
return nil
}

var Tmp = TokStart
var poundCount = 0
var parenCount = 0
Expand Down
55 changes: 48 additions & 7 deletions Tests/SwiftParserTest/LexerTests.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -352,11 +352,6 @@ public class LexerTests: XCTestCase {
lexeme(.regexLiteral, "#/abc|#def/#"),
lexeme(.eof, ""),
]),
("#/abc|#def/", [
lexeme(.pound, "#"),
lexeme(.regexLiteral, "/abc|#def/"),
lexeme(.eof, ""),
]),
("#/abc\n/#", [
lexeme(.pound, "#"),
lexeme(.unspacedBinaryOperator, "/"),
Expand Down Expand Up @@ -567,15 +562,61 @@ public class LexerTests: XCTestCase {
"""
n /= 2 // foo
"""
let lexemes = data.withUTF8 { buf in
data.withUTF8 { buf in
let lexemes = Lexer.lex(buf)
AssertEqualTokens(lexemes, [
lexeme(.identifier, "n ", trailing: 1),
lexeme(.spacedBinaryOperator, "/= ", trailing: 1),
lexeme(.integerLiteral, "2 ", trailing: 1),
lexeme(.eof, "// foo", leading: 6),
])
return lexemes
}
}

do {
var data =
"""
UIColor(white: 216.0/255.0, alpha: 44.0/255.0)
"""
data.withUTF8 { buf in
let lexemes = Lexer.lex(buf)
AssertEqualTokens(lexemes, [
lexeme(.identifier, "UIColor"),
lexeme(.leftParen, "("),
lexeme(.identifier, "white"),
lexeme(.colon, ": ", trailing: 1),
lexeme(.floatingLiteral, "216.0"),
lexeme(.unspacedBinaryOperator, "/"),
lexeme(.floatingLiteral, "255.0"),
lexeme(.comma, ", ", trailing: 1),
lexeme(.identifier, "alpha"),
lexeme(.colon, ": ", trailing: 1),
lexeme(.floatingLiteral, "44.0"),
lexeme(.unspacedBinaryOperator, "/"),
lexeme(.floatingLiteral, "255.0"),
lexeme(.rightParen, ")"),
lexeme(.eof, ""),
])
}
}

do {
var data =
"""
#/abc|#def/
"""
data.withUTF8 { buf in
let lexemes = Lexer.lex(buf)
AssertEqualTokens(lexemes, [
lexeme(.pound, "#"),
lexeme(.unspacedBinaryOperator, "/"),
lexeme(.identifier, "abc"),
lexeme(.unspacedBinaryOperator, "|"),
lexeme(.pound, "#"),
lexeme(.identifier, "def"),
lexeme(.postfixOperator, "/"),
lexeme(.eof, ""),
])
}
}
}
Expand Down