Mihaela M
ceb12295a4
Blank lines between a block scalar header and its first content line come before the indent token, so the earlier blank-line capture skipped them. Buffer leading blanks while the block indentation is still pending and flush them as empty content once the indent is established, in the shared indentation path used by both scan loops. Also fix folded bodies to emit a break for a leading blank rather than folding it into a leading space. This closes the last block-scalar blank-line edge from #57.
395 lines
13 KiB
Swift
395 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 pendingBlockScalarLeadingBlankLines = 0
|
|
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)
|
|
}
|
|
}
|