refactor: Use tabs for indent
This commit is contained in:
T. R. Bernstein
@@ -1,272 +1,272 @@
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/// Creates a checker that will stop parsing if it encounters a list of tags.
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/// Useful for example for scanning until a given "end"-node.
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public func until(_ tags: [String]) -> ((TokenParser, Token) -> Bool) {
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{ _, token in
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if let name = token.components.first {
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for tag in tags where name == tag {
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return true
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}
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}
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{ _, token in
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if let name = token.components.first {
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for tag in tags where name == tag {
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return true
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}
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}
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return false
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}
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return false
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}
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}
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/// A class for parsing an array of tokens and converts them into a collection of Node's
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public class TokenParser {
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/// Parser for finding a kind of node
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public typealias TagParser = (TokenParser, Token) throws -> NodeType
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/// Parser for finding a kind of node
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public typealias TagParser = (TokenParser, Token) throws -> NodeType
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fileprivate var tokens: [Token]
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fileprivate(set) var parsedTokens: [Token] = []
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fileprivate let environment: Environment
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fileprivate var previousWhiteSpace: WhitespaceBehaviour.Behaviour?
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fileprivate var tokens: [Token]
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fileprivate(set) var parsedTokens: [Token] = []
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fileprivate let environment: Environment
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fileprivate var previousWhiteSpace: WhitespaceBehaviour.Behaviour?
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/// Simple initializer
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public init(tokens: [Token], environment: Environment) {
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self.tokens = tokens
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self.environment = environment
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}
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/// Simple initializer
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public init(tokens: [Token], environment: Environment) {
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self.tokens = tokens
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self.environment = environment
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}
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/// Parse the given tokens into nodes
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public func parse() throws -> [NodeType] {
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try parse(nil)
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}
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/// Parse the given tokens into nodes
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public func parse() throws -> [NodeType] {
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try parse(nil)
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}
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/// Parse nodes until a specific "something" is detected, determined by the provided closure.
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/// Combine this with the `until(:)` function above to scan nodes until a given token.
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public func parse(_ parseUntil: ((_ parser: TokenParser, _ token: Token) -> (Bool))?) throws -> [NodeType] {
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var nodes = [NodeType]()
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/// Parse nodes until a specific "something" is detected, determined by the provided closure.
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/// Combine this with the `until(:)` function above to scan nodes until a given token.
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public func parse(_ parseUntil: ((_ parser: TokenParser, _ token: Token) -> (Bool))?) throws -> [NodeType] {
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var nodes = [NodeType]()
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while !tokens.isEmpty {
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guard let token = nextToken() else { break }
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while !tokens.isEmpty {
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guard let token = nextToken() else { break }
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switch token.kind {
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case .text:
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nodes.append(TextNode(text: token.contents, trimBehaviour: trimBehaviour))
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case .variable:
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previousWhiteSpace = nil
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try nodes.append(VariableNode.parse(self, token: token))
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case .block:
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previousWhiteSpace = token.whitespace?.trailing
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if let parseUntil = parseUntil, parseUntil(self, token) {
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prependToken(token)
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return nodes
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}
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switch token.kind {
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case .text:
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nodes.append(TextNode(text: token.contents, trimBehaviour: trimBehaviour))
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case .variable:
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previousWhiteSpace = nil
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try nodes.append(VariableNode.parse(self, token: token))
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case .block:
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previousWhiteSpace = token.whitespace?.trailing
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if let parseUntil = parseUntil, parseUntil(self, token) {
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prependToken(token)
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return nodes
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}
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if var tag = token.components.first {
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do {
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// special case for labeled tags (such as for loops)
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if tag.hasSuffix(":") && token.components.count >= 2 {
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tag = token.components[1]
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}
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if var tag = token.components.first {
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do {
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// special case for labeled tags (such as for loops)
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if tag.hasSuffix(":") && token.components.count >= 2 {
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tag = token.components[1]
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}
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let parser = try environment.findTag(name: tag)
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let node = try parser(self, token)
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nodes.append(node)
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} catch {
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throw error.withToken(token)
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}
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}
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case .comment:
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previousWhiteSpace = nil
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continue
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}
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}
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let parser = try environment.findTag(name: tag)
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let node = try parser(self, token)
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nodes.append(node)
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} catch {
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throw error.withToken(token)
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}
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}
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case .comment:
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previousWhiteSpace = nil
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continue
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}
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}
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return nodes
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}
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return nodes
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}
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/// Pop the next token (returning it)
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public func nextToken() -> Token? {
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if !tokens.isEmpty {
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let nextToken = tokens.remove(at: 0)
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parsedTokens.append(nextToken)
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return nextToken
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}
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/// Pop the next token (returning it)
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public func nextToken() -> Token? {
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if !tokens.isEmpty {
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let nextToken = tokens.remove(at: 0)
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parsedTokens.append(nextToken)
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return nextToken
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}
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return nil
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}
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return nil
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}
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func peekWhitespace() -> WhitespaceBehaviour.Behaviour? {
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tokens.first?.whitespace?.leading
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}
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func peekWhitespace() -> WhitespaceBehaviour.Behaviour? {
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tokens.first?.whitespace?.leading
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}
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/// Insert a token
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public func prependToken(_ token: Token) {
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tokens.insert(token, at: 0)
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if parsedTokens.last == token {
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parsedTokens.removeLast()
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}
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}
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/// Insert a token
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public func prependToken(_ token: Token) {
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tokens.insert(token, at: 0)
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if parsedTokens.last == token {
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parsedTokens.removeLast()
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}
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}
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/// Create filter expression from a string contained in provided token
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public func compileFilter(_ filterToken: String, containedIn token: Token) throws -> Resolvable {
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try environment.compileFilter(filterToken, containedIn: token)
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}
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/// Create filter expression from a string contained in provided token
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public func compileFilter(_ filterToken: String, containedIn token: Token) throws -> Resolvable {
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try environment.compileFilter(filterToken, containedIn: token)
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}
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/// Create boolean expression from components contained in provided token
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public func compileExpression(components: [String], token: Token) throws -> Expression {
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try environment.compileExpression(components: components, containedIn: token)
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}
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/// Create boolean expression from components contained in provided token
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public func compileExpression(components: [String], token: Token) throws -> Expression {
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try environment.compileExpression(components: components, containedIn: token)
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}
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/// Create resolvable (i.e. range variable or filter expression) from a string contained in provided token
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public func compileResolvable(_ token: String, containedIn containingToken: Token) throws -> Resolvable {
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try environment.compileResolvable(token, containedIn: containingToken)
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}
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/// Create resolvable (i.e. range variable or filter expression) from a string contained in provided token
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public func compileResolvable(_ token: String, containedIn containingToken: Token) throws -> Resolvable {
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try environment.compileResolvable(token, containedIn: containingToken)
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}
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private var trimBehaviour: TrimBehaviour {
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var behaviour: TrimBehaviour = .nothing
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private var trimBehaviour: TrimBehaviour {
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var behaviour: TrimBehaviour = .nothing
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if let leading = previousWhiteSpace {
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if leading == .unspecified {
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behaviour.leading = environment.trimBehaviour.trailing
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} else {
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behaviour.leading = leading == .trim ? .whitespaceAndNewLines : .nothing
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}
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}
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if let trailing = peekWhitespace() {
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if trailing == .unspecified {
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behaviour.trailing = environment.trimBehaviour.leading
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} else {
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behaviour.trailing = trailing == .trim ? .whitespaceAndNewLines : .nothing
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}
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}
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if let leading = previousWhiteSpace {
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if leading == .unspecified {
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behaviour.leading = environment.trimBehaviour.trailing
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} else {
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behaviour.leading = leading == .trim ? .whitespaceAndNewLines : .nothing
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}
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}
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if let trailing = peekWhitespace() {
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if trailing == .unspecified {
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behaviour.trailing = environment.trimBehaviour.leading
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} else {
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behaviour.trailing = trailing == .trim ? .whitespaceAndNewLines : .nothing
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}
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}
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return behaviour
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}
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return behaviour
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}
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}
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extension Environment {
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func findTag(name: String) throws -> Extension.TagParser {
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for ext in extensions {
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if let filter = ext.tags[name] {
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return filter
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}
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}
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func findTag(name: String) throws -> Extension.TagParser {
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for ext in extensions {
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if let filter = ext.tags[name] {
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return filter
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}
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}
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throw TemplateSyntaxError("Unknown template tag '\(name)'")
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}
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throw TemplateSyntaxError("Unknown template tag '\(name)'")
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}
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func findFilter(_ name: String) throws -> FilterType {
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for ext in extensions {
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if let filter = ext.filters[name] {
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return filter
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}
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}
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func findFilter(_ name: String) throws -> FilterType {
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for ext in extensions {
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if let filter = ext.filters[name] {
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return filter
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}
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}
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let suggestedFilters = self.suggestedFilters(for: name)
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if suggestedFilters.isEmpty {
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throw TemplateSyntaxError("Unknown filter '\(name)'.")
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} else {
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throw TemplateSyntaxError(
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"""
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Unknown filter '\(name)'. \
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Found similar filters: \(suggestedFilters.map { "'\($0)'" }.joined(separator: ", ")).
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"""
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)
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}
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}
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let suggestedFilters = self.suggestedFilters(for: name)
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if suggestedFilters.isEmpty {
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throw TemplateSyntaxError("Unknown filter '\(name)'.")
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} else {
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throw TemplateSyntaxError(
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"""
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Unknown filter '\(name)'. \
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Found similar filters: \(suggestedFilters.map { "'\($0)'" }.joined(separator: ", ")).
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"""
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)
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}
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}
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private func suggestedFilters(for name: String) -> [String] {
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let allFilters = extensions.flatMap { $0.filters.keys }
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private func suggestedFilters(for name: String) -> [String] {
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let allFilters = extensions.flatMap { $0.filters.keys }
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let filtersWithDistance = allFilters
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.map { (filterName: $0, distance: $0.levenshteinDistance(name)) }
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// do not suggest filters which names are shorter than the distance
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.filter { $0.filterName.count > $0.distance }
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guard let minDistance = filtersWithDistance.min(by: { $0.distance < $1.distance })?.distance else {
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return []
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}
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// suggest all filters with the same distance
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return filtersWithDistance.filter { $0.distance == minDistance }.map { $0.filterName }
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}
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let filtersWithDistance = allFilters
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.map { (filterName: $0, distance: $0.levenshteinDistance(name)) }
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// do not suggest filters which names are shorter than the distance
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.filter { $0.filterName.count > $0.distance }
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guard let minDistance = filtersWithDistance.min(by: { $0.distance < $1.distance })?.distance else {
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return []
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}
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// suggest all filters with the same distance
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return filtersWithDistance.filter { $0.distance == minDistance }.map { $0.filterName }
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}
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/// Create filter expression from a string
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public func compileFilter(_ token: String) throws -> Resolvable {
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try FilterExpression(token: token, environment: self)
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}
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/// Create filter expression from a string
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public func compileFilter(_ token: String) throws -> Resolvable {
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try FilterExpression(token: token, environment: self)
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}
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/// Create filter expression from a string contained in provided token
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public func compileFilter(_ filterToken: String, containedIn containingToken: Token) throws -> Resolvable {
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do {
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return try FilterExpression(token: filterToken, environment: self)
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} catch {
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guard var syntaxError = error as? TemplateSyntaxError, syntaxError.token == nil else {
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throw error
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}
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// find offset of filter in the containing token so that only filter is highligted, not the whole token
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if let filterTokenRange = containingToken.contents.range(of: filterToken) {
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var location = containingToken.sourceMap.location
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location.lineOffset += containingToken.contents.distance(
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from: containingToken.contents.startIndex,
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to: filterTokenRange.lowerBound
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)
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syntaxError.token = .variable(
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value: filterToken,
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at: SourceMap(filename: containingToken.sourceMap.filename, location: location)
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)
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} else {
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syntaxError.token = containingToken
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}
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throw syntaxError
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}
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}
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/// Create filter expression from a string contained in provided token
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public func compileFilter(_ filterToken: String, containedIn containingToken: Token) throws -> Resolvable {
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do {
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return try FilterExpression(token: filterToken, environment: self)
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} catch {
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guard var syntaxError = error as? TemplateSyntaxError, syntaxError.token == nil else {
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throw error
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}
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// find offset of filter in the containing token so that only filter is highligted, not the whole token
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if let filterTokenRange = containingToken.contents.range(of: filterToken) {
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var location = containingToken.sourceMap.location
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location.lineOffset += containingToken.contents.distance(
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from: containingToken.contents.startIndex,
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to: filterTokenRange.lowerBound
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)
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syntaxError.token = .variable(
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value: filterToken,
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at: SourceMap(filename: containingToken.sourceMap.filename, location: location)
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)
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} else {
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syntaxError.token = containingToken
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}
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throw syntaxError
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}
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}
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/// Create resolvable (i.e. range variable or filter expression) from a string
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public func compileResolvable(_ token: String) throws -> Resolvable {
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try RangeVariable(token, environment: self)
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?? compileFilter(token)
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}
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/// Create resolvable (i.e. range variable or filter expression) from a string
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public func compileResolvable(_ token: String) throws -> Resolvable {
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try RangeVariable(token, environment: self)
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?? compileFilter(token)
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}
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/// Create resolvable (i.e. range variable or filter expression) from a string contained in provided token
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public func compileResolvable(_ token: String, containedIn containingToken: Token) throws -> Resolvable {
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try RangeVariable(token, environment: self, containedIn: containingToken)
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?? compileFilter(token, containedIn: containingToken)
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}
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/// Create resolvable (i.e. range variable or filter expression) from a string contained in provided token
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public func compileResolvable(_ token: String, containedIn containingToken: Token) throws -> Resolvable {
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try RangeVariable(token, environment: self, containedIn: containingToken)
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?? compileFilter(token, containedIn: containingToken)
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}
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/// Create boolean expression from components contained in provided token
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public func compileExpression(components: [String], containedIn token: Token) throws -> Expression {
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try IfExpressionParser.parser(components: components, environment: self, token: token).parse()
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}
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/// Create boolean expression from components contained in provided token
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public func compileExpression(components: [String], containedIn token: Token) throws -> Expression {
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try IfExpressionParser.parser(components: components, environment: self, token: token).parse()
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}
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}
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// https://en.wikipedia.org/wiki/Levenshtein_distance#Iterative_with_two_matrix_rows
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extension String {
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subscript(_ index: Int) -> Character {
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self[self.index(self.startIndex, offsetBy: index)]
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}
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subscript(_ index: Int) -> Character {
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self[self.index(self.startIndex, offsetBy: index)]
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}
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func levenshteinDistance(_ target: String) -> Int {
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// create two work vectors of integer distances
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var last, current: [Int]
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func levenshteinDistance(_ target: String) -> Int {
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// create two work vectors of integer distances
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var last, current: [Int]
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// initialize v0 (the previous row of distances)
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// this row is A[0][i]: edit distance for an empty s
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// the distance is just the number of characters to delete from t
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last = [Int](0...target.count)
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current = [Int](repeating: 0, count: target.count + 1)
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// initialize v0 (the previous row of distances)
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// this row is A[0][i]: edit distance for an empty s
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// the distance is just the number of characters to delete from t
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last = [Int](0...target.count)
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current = [Int](repeating: 0, count: target.count + 1)
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for selfIndex in 0..<self.count {
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// calculate v1 (current row distances) from the previous row v0
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for selfIndex in 0..<self.count {
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// calculate v1 (current row distances) from the previous row v0
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// first element of v1 is A[i+1][0]
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// edit distance is delete (i+1) chars from s to match empty t
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current[0] = selfIndex + 1
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// first element of v1 is A[i+1][0]
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// edit distance is delete (i+1) chars from s to match empty t
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current[0] = selfIndex + 1
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// use formula to fill in the rest of the row
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for targetIndex in 0..<target.count {
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current[targetIndex + 1] = Swift.min(
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last[targetIndex + 1] + 1,
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current[targetIndex] + 1,
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last[targetIndex] + (self[selfIndex] == target[targetIndex] ? 0 : 1)
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)
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}
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// use formula to fill in the rest of the row
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for targetIndex in 0..<target.count {
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current[targetIndex + 1] = Swift.min(
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last[targetIndex + 1] + 1,
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current[targetIndex] + 1,
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last[targetIndex] + (self[selfIndex] == target[targetIndex] ? 0 : 1)
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)
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}
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// copy v1 (current row) to v0 (previous row) for next iteration
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last = current
|
||||
}
|
||||
// copy v1 (current row) to v0 (previous row) for next iteration
|
||||
last = current
|
||||
}
|
||||
|
||||
return current[target.count]
|
||||
}
|
||||
return current[target.count]
|
||||
}
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user