Mihaela M
d3ff3823a5
The scanner dropped every blank line within and after a block scalar, so a literal block lost internal blank lines, a folded block turned a blank line into a space rather than a newline, and the keep indicator could not preserve trailing blank lines. Capture blank lines as empty content in both the batch scan loop and the streaming TokenCursor loop, which had drifted as duplicate copies. Rework blockScalarValue to apply literal versus folded line semantics and clip/strip/keep chomping over the captured lines; content without blank lines is unchanged. Re-pin the multiline-scalar test whose expectation encoded the old dropped-blank behavior, and add a chomping-and-folding test matrix.
394 lines
13 KiB
Swift
394 lines
13 KiB
Swift
extension PureYAML.Parsing {
|
|
struct Scanner {
|
|
init() {}
|
|
|
|
func scan(_ yaml: String) throws -> [Token] {
|
|
var state = State(reader: Reader(yaml))
|
|
state.append(.streamStart)
|
|
|
|
while !state.reader.isAtEnd {
|
|
if isLineBreak(state.reader.peek()) {
|
|
state.reader.advance()
|
|
captureBlockScalarBlankLine(&state)
|
|
state.isAtLineStart = true
|
|
continue
|
|
}
|
|
|
|
if state.isAtLineStart {
|
|
try scanIndentation(&state)
|
|
if state.reader.isAtEnd {
|
|
break
|
|
}
|
|
if isLineBreak(state.reader.peek()) {
|
|
continue
|
|
}
|
|
if try scanDirectiveOrDocumentMarker(&state) {
|
|
continue
|
|
}
|
|
state.isAtLineStart = false
|
|
}
|
|
|
|
try scanToken(&state)
|
|
}
|
|
|
|
closeIndentation(&state)
|
|
state.append(.streamEnd)
|
|
return state.tokens
|
|
}
|
|
}
|
|
}
|
|
|
|
extension PureYAML.Parsing.Scanner {
|
|
struct State {
|
|
var reader: PureYAML.Parsing.Reader
|
|
var tokens: [PureYAML.Parsing.Token] = []
|
|
var indentation: [Int] = [0]
|
|
var isAtLineStart = true
|
|
var hasDocumentContent = false
|
|
var hasDocumentStartMarker = false
|
|
var isDocumentClosed = false
|
|
var flowDepth = 0
|
|
var flowContexts: [PureYAML.Parsing.ScannerFlowContext] = []
|
|
var validImplicitIndentation: Set<Int> = []
|
|
var pendingBlockScalarIndentation = false
|
|
var pendingBlockScalarIndentationIndicator: Int?
|
|
var blockScalarIndentation: Int?
|
|
var blockScalarContentPrefix = ""
|
|
var tagHandles = [
|
|
"!": "!",
|
|
"!!": "tag:yaml.org,2002:",
|
|
]
|
|
|
|
mutating func append(_ kind: PureYAML.Parsing.TokenKind) {
|
|
let mark = reader.mark
|
|
tokens.append(PureYAML.Parsing.Token(kind: kind, mark: mark, endMark: mark))
|
|
markDocumentContentIfNeeded(kind)
|
|
}
|
|
|
|
mutating func append(
|
|
_ kind: PureYAML.Parsing.TokenKind,
|
|
mark: PureYAML.Parsing.Mark,
|
|
endMark: PureYAML.Parsing.Mark,
|
|
) {
|
|
tokens.append(PureYAML.Parsing.Token(kind: kind, mark: mark, endMark: endMark))
|
|
markDocumentContentIfNeeded(kind)
|
|
}
|
|
|
|
mutating func markDocumentContentIfNeeded(_ kind: PureYAML.Parsing.TokenKind) {
|
|
switch kind {
|
|
case .comment, .dedent, .documentEnd, .documentStart, .indent, .streamEnd, .streamStart:
|
|
return
|
|
default:
|
|
hasDocumentContent = true
|
|
}
|
|
}
|
|
|
|
var isExpectingFlowMappingKey: Bool {
|
|
flowContexts.last?.kind == .mapping
|
|
&& flowContexts.last?.isExpectingKey == true
|
|
}
|
|
}
|
|
}
|
|
|
|
extension PureYAML.Parsing.Scanner {
|
|
func scanToken(_ state: inout State) throws {
|
|
skipSeparation(&state)
|
|
guard let character = state.reader.peek(), !isLineBreak(character) else {
|
|
return
|
|
}
|
|
|
|
if state.blockScalarIndentation != nil {
|
|
scanBlockScalarContent(&state)
|
|
return
|
|
}
|
|
if try scanLineIndicatorToken(character, state: &state) {
|
|
return
|
|
}
|
|
if scanFlowToken(character, state: &state) {
|
|
return
|
|
}
|
|
if try scanQuotedOrBlockScalarToken(character, state: &state) {
|
|
return
|
|
}
|
|
if try scanNodePropertyToken(character, state: &state) {
|
|
return
|
|
}
|
|
scanPlainScalar(&state)
|
|
}
|
|
|
|
func scanLineIndicatorToken(
|
|
_ character: Character,
|
|
state: inout State,
|
|
) throws -> Bool {
|
|
switch character {
|
|
case "#":
|
|
scanComment(&state)
|
|
return true
|
|
case "-" where isBlockEntry(state.reader):
|
|
scanFixedToken(.blockEntry, state: &state)
|
|
return true
|
|
case "?" where isIndicatorBoundary(state.reader.peek(offset: 1)):
|
|
scanFixedToken(.mappingKey, state: &state)
|
|
return true
|
|
case ":" where isAtMappingValueIndicator(state: state):
|
|
scanFixedToken(.mappingValue, state: &state)
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
func scanFlowToken(
|
|
_ character: Character,
|
|
state: inout State,
|
|
) -> Bool {
|
|
switch character {
|
|
case "[":
|
|
state.flowDepth += 1
|
|
state.flowContexts.append(.init(kind: .sequence, isExpectingKey: false))
|
|
scanFixedToken(.flowSequenceStart, state: &state)
|
|
return true
|
|
case "]":
|
|
state.flowDepth = max(0, state.flowDepth - 1)
|
|
scanFixedToken(.flowSequenceEnd, state: &state)
|
|
_ = state.flowContexts.popLast()
|
|
return true
|
|
case "{":
|
|
state.flowDepth += 1
|
|
state.flowContexts.append(.init(kind: .mapping, isExpectingKey: true))
|
|
scanFixedToken(.flowMappingStart, state: &state)
|
|
return true
|
|
case "}":
|
|
state.flowDepth = max(0, state.flowDepth - 1)
|
|
scanFixedToken(.flowMappingEnd, state: &state)
|
|
_ = state.flowContexts.popLast()
|
|
return true
|
|
case ",":
|
|
scanFixedToken(.flowEntry, state: &state)
|
|
if state.flowContexts.last?.kind == .mapping {
|
|
state.flowContexts[state.flowContexts.count - 1].isExpectingKey = true
|
|
}
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
func scanNodePropertyToken(
|
|
_ character: Character,
|
|
state: inout State,
|
|
) throws -> Bool {
|
|
switch character {
|
|
case "&":
|
|
try scanNamedToken(
|
|
kind: PureYAML.Parsing.TokenKind.anchor,
|
|
missingNameError: PureYAML.Parsing.ParseError.expectedAnchorName,
|
|
state: &state,
|
|
)
|
|
return true
|
|
case "*":
|
|
try scanNamedToken(
|
|
kind: PureYAML.Parsing.TokenKind.alias,
|
|
missingNameError: PureYAML.Parsing.ParseError.expectedAliasName,
|
|
state: &state,
|
|
)
|
|
return true
|
|
case "!":
|
|
try scanTag(&state)
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
func scanQuotedOrBlockScalarToken(
|
|
_ character: Character,
|
|
state: inout State,
|
|
) throws -> Bool {
|
|
switch character {
|
|
case "\"":
|
|
try scanQuotedScalar(.doubleQuoted, state: &state)
|
|
return true
|
|
case "'":
|
|
try scanQuotedScalar(.singleQuoted, state: &state)
|
|
return true
|
|
case "|":
|
|
scanBlockScalarHeader(.literal, state: &state)
|
|
return true
|
|
case ">":
|
|
scanBlockScalarHeader(.folded, state: &state)
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
func skipSeparation(_ state: inout State) {
|
|
while state.reader.peek() == " " {
|
|
state.reader.advance()
|
|
}
|
|
}
|
|
|
|
func scanFixedToken(
|
|
_ kind: PureYAML.Parsing.TokenKind,
|
|
state: inout State,
|
|
) {
|
|
let start = state.reader.mark
|
|
state.reader.advance()
|
|
state.append(kind, mark: start, endMark: state.reader.mark)
|
|
if case .blockEntry = kind, hasNodeOnSameLine(afterCurrentPositionIn: state.reader) {
|
|
state.validImplicitIndentation.insert(start.column + 1)
|
|
}
|
|
if case .mappingValue = kind, state.flowContexts.last?.kind == .mapping {
|
|
state.flowContexts[state.flowContexts.count - 1].isExpectingKey = false
|
|
}
|
|
}
|
|
|
|
func scanComment(_ state: inout State) {
|
|
let start = state.reader.mark
|
|
state.reader.advance()
|
|
if state.reader.peek() == " " {
|
|
state.reader.advance()
|
|
}
|
|
let value = state.reader.consume { character in
|
|
!isLineBreak(character)
|
|
}
|
|
state.append(.comment(value), mark: start, endMark: state.reader.mark)
|
|
}
|
|
|
|
func scanQuotedScalar(
|
|
_ style: PureYAML.Parsing.ScalarStyle,
|
|
state: inout State,
|
|
) throws {
|
|
let start = state.reader.mark
|
|
let quote: Character = style == .doubleQuoted ? "\"" : "'"
|
|
state.reader.advance()
|
|
var value = ""
|
|
var previousWasEscape = false
|
|
while let character = state.reader.peek() {
|
|
if style == .singleQuoted, character == quote, state.reader.peek(offset: 1) == quote {
|
|
value.append(character)
|
|
state.reader.advance()
|
|
value.append(character)
|
|
state.reader.advance()
|
|
continue
|
|
}
|
|
if character == quote, !previousWasEscape {
|
|
break
|
|
}
|
|
value.append(character)
|
|
previousWasEscape = character == "\\" && style == .doubleQuoted && !previousWasEscape
|
|
state.reader.advance()
|
|
if character != "\\" {
|
|
previousWasEscape = false
|
|
}
|
|
}
|
|
guard state.reader.peek() == quote else {
|
|
throw PureYAML.Parsing.ParseError.unterminatedQuotedString(line: start.line)
|
|
}
|
|
state.reader.advance()
|
|
appendMappingKeyIfNeeded(start: start, state: &state)
|
|
state.append(.scalar(value: value, style: style), mark: start, endMark: state.reader.mark)
|
|
}
|
|
|
|
func scanBlockScalarHeader(
|
|
_ style: PureYAML.Parsing.BlockScalarStyle,
|
|
state: inout State,
|
|
) {
|
|
let start = state.reader.mark
|
|
var chomping = PureYAML.Parsing.BlockScalarChomping.clip
|
|
var indentationIndicator: Int?
|
|
state.reader.advance()
|
|
while let character = state.reader.peek(), isBlockScalarHeaderCharacter(character) {
|
|
if character == "-" {
|
|
chomping = .strip
|
|
} else if character == "+" {
|
|
chomping = .keep
|
|
} else if character.isNumber {
|
|
indentationIndicator = Int(String(character))
|
|
}
|
|
state.reader.advance()
|
|
}
|
|
state.append(
|
|
.blockScalarHeader(style: style, chomping: chomping),
|
|
mark: start,
|
|
endMark: state.reader.mark,
|
|
)
|
|
state.pendingBlockScalarIndentation = true
|
|
state.pendingBlockScalarIndentationIndicator = indentationIndicator
|
|
}
|
|
|
|
func scanBlockScalarContent(_ state: inout State) {
|
|
let start = state.reader.mark
|
|
let value = state.blockScalarContentPrefix + state.reader.consume { character in
|
|
!isLineBreak(character)
|
|
}
|
|
state.blockScalarContentPrefix = ""
|
|
state.append(.scalar(value: value, style: .plain), mark: start, endMark: state.reader.mark)
|
|
}
|
|
|
|
func scanNamedToken(
|
|
kind: (String) -> PureYAML.Parsing.TokenKind,
|
|
missingNameError: (Int) -> PureYAML.Parsing.ParseError,
|
|
state: inout State,
|
|
) throws {
|
|
let start = state.reader.mark
|
|
state.reader.advance()
|
|
let name = state.reader.consume { character in
|
|
!isTokenTerminator(character)
|
|
}
|
|
guard !name.isEmpty else {
|
|
throw missingNameError(start.line)
|
|
}
|
|
state.append(kind(name), mark: start, endMark: state.reader.mark)
|
|
}
|
|
|
|
func scanTag(_ state: inout State) throws {
|
|
let start = state.reader.mark
|
|
state.reader.advance()
|
|
var value = "!"
|
|
if state.reader.peek() == "<" {
|
|
value.append(state.reader.advance() ?? "<")
|
|
var didClose = false
|
|
while let character = state.reader.peek() {
|
|
value.append(character)
|
|
state.reader.advance()
|
|
if character == ">" {
|
|
didClose = true
|
|
break
|
|
}
|
|
}
|
|
guard didClose else {
|
|
throw PureYAML.Parsing.ParseError.unterminatedTag(line: start.line)
|
|
}
|
|
} else {
|
|
value += state.reader.consume { character in
|
|
!isTokenTerminator(character)
|
|
}
|
|
value = expandTag(value, state: state)
|
|
}
|
|
state.append(.tag(value), mark: start, endMark: state.reader.mark)
|
|
}
|
|
|
|
func scanPlainScalar(_ state: inout State) {
|
|
let start = state.reader.mark
|
|
var value = ""
|
|
while let character = state.reader.peek() {
|
|
if shouldEndPlainScalar(character, state: state, accumulated: value) {
|
|
break
|
|
}
|
|
value.append(character)
|
|
state.reader.advance()
|
|
}
|
|
var trimmed = trimTrailingSpaces(value)
|
|
let isMappingKey = appendMappingKeyIfNeeded(start: start, state: &state)
|
|
if !isMappingKey {
|
|
trimmed = scanPlainScalarContinuations(
|
|
after: trimmed,
|
|
state: &state,
|
|
)
|
|
}
|
|
state.append(.scalar(value: trimmed, style: .plain), mark: start, endMark: state.reader.mark)
|
|
}
|
|
}
|