85 lines
1.8 KiB
Swift
85 lines
1.8 KiB
Swift
import Foundation
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public struct TemplateSyntaxError : Error, Equatable, CustomStringConvertible {
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public let description:String
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public init(_ description:String) {
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self.description = description
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}
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}
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public func ==(lhs:TemplateSyntaxError, rhs:TemplateSyntaxError) -> Bool {
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return lhs.description == rhs.description
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}
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public protocol NodeType {
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/// Render the node in the given context
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func render(_ context:Context) throws -> String
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}
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/// Render the collection of nodes in the given context
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public func renderNodes(_ nodes:[NodeType], _ context:Context) throws -> String {
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return try nodes.map { try $0.render(context) }.joined(separator: "")
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}
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public class SimpleNode : NodeType {
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public let handler:(Context) throws -> String
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public init(handler: @escaping (Context) throws -> String) {
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self.handler = handler
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}
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public func render(_ context: Context) throws -> String {
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return try handler(context)
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}
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}
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public class TextNode : NodeType {
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public let text:String
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public init(text:String) {
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self.text = text
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}
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public func render(_ context:Context) throws -> String {
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return self.text
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}
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}
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public protocol Resolvable {
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func resolve(_ context: Context) throws -> Any?
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}
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public class VariableNode : NodeType {
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public let variable: Resolvable
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public init(variable: Resolvable) {
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self.variable = variable
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}
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public init(variable: String) {
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self.variable = Variable(variable)
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}
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public func render(_ context: Context) throws -> String {
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let result = try variable.resolve(context)
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if let result = result as? String {
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return result
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} else if let result = result as? CustomStringConvertible {
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return result.description
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} else if let result = result as? NSObject {
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return result.description
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}
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return ""
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}
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}
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