libsyntax typealias creation

typealias.swift

import SwiftSyntax

@greeble(bork) typealias Element = Int

let typeAliasKeyword = SyntaxFactory.makeTypealiasKeyword(leadingTrivia: .spaces(1),
                                                                 trailingTrivia: .spaces(1))
let elementID = SyntaxFactory.makeIdentifier("Element", leadingTrivia: .zero, trailingTrivia: .spaces(1))
let equal = SyntaxFactory.makeEqualToken(leadingTrivia: Trivia.zero, trailingTrivia: .spaces(1))
let intType = SyntaxFactory.makeTypeIdentifier("Int", leadingTrivia: .zero, trailingTrivia: .zero)
let initializer = SyntaxFactory.makeTypeInitializerClause(equal: equal, value: intType)

let openParen = SyntaxFactory.makeLeftParenToken()
let closeParen = SyntaxFactory.makeRightParenToken()

let balancedTokens = [openParen, SyntaxFactory.makeIdentifier("bork", leadingTrivia: .zero,
                                                              trailingTrivia: .zero), closeParen]
let balancedTokenSyntax = SyntaxFactory.makeTokenList(balancedTokens)

let atsign = SyntaxFactory.makeAtSignToken(leadingTrivia: .zero, trailingTrivia: .zero)
let attributeName = SyntaxFactory.makeIdentifier("greeble", leadingTrivia: .zero, trailingTrivia: .zero)

let attribute = SyntaxFactory.makeAttribute(atSignToken: atsign, 
                                            attributeName: attributeName, 
                                            balancedTokens: balancedTokenSyntax)
let attributes = SyntaxFactory.makeAttributeList([attribute])

let typeAlias = SyntaxFactory.makeTypealiasDecl(attributes: attributes, 
                                                accessLevelModifier: nil,
                                                typealiasKeyword: typeAliasKeyword,
                                                identifier: elementID,
                                                genericParameterClause: nil,
                                                initializer: initializer)