@@ -8,6 +8,12 @@
88
99import Foundation
1010
11+typealias Lines = [String]
12+typealias Element = [String]
13+let commentChars = CharacterSet.init(charactersIn: "#/")
14+let styleCharecters = CharacterSet.init(charactersIn: "_*")
15+
16+
1117enum BracketStyle {
1218 case square
1319 case round
@@ -61,11 +67,11 @@ default:
6167 if let surl = args.popFirst() {
6268 outputUrl = URL(fileURLWithPath: surl)
6369 }
64− case "-s":
70+ case "-b:s":
6571 style = .square
66− case "-r":
72+ case "-b:r":
6773 style = .round
68− case "-l":
74+ case "-b:l":
6975 style = .line
7076 default:
7177 return
@@ -81,7 +87,6 @@ enum ElementStyle: String {
8187 case italic = "italic"
8288 case boldItalic = "bold-italic"
8389}
84−let styleCharecters = CharacterSet.init(charactersIn: "_*")
8590extension String.SubSequence {
8691 var style: ElementStyle {
8792 let num = self.prefix(while: {styleCharecters.contains($0.unicodeScalars.first!)}).count
@@ -100,79 +105,209 @@ extension String.SubSequence {
100105 return self.trimmingCharacters(in: styleCharecters)
101106 }
102107}
103−func process(mth: String) -> String {
104− let whitespace = CharacterSet.whitespaces
108+
109+func process(element: Element) -> String {
110+ var out = ""
105111
112+ var inMatrix = false
113+ var first = false
106114 var seperated = false
107− var afterSeparator: [String.SubSequence] = []
115+ var afterSeparator: [Substring] = []
108116
109− var out = "<math>"
110− let lines = mth.split(separator: "\n", omittingEmptySubsequences: false)
111− .map {$0.trimmingCharacters(in: .whitespaces)}
112− var insideMatrix = false
113− func pureProcess(line: Substring) {
117+ var small = false
118+
119+ let arrows = CharacterSet.init(charactersIn: "⟺⟷⟼⟻⟶⟹⟵⟸")
120+
121+ let nEl = element.map { (el) -> String in
122+ switch el {
123+ case let l where l.last == ">" && l.first == "<" && l.dropLast().dropFirst().filter({$0 == "="}).count > 0:
124+ small = true
125+ return "⟺"
126+ case let l where l.last == ">" && l.first == "<" && l.dropLast().dropFirst().filter({$0 == "-"}).count > 0:
127+ small = true
128+ return "⟷"
129+ case let l where l.last == ">" && l.first == "|" && l.dropLast().dropFirst().filter({$0 == "-"}).count > 0:
130+ small = true
131+ return "⟼"
132+ case let l where l.last == "|" && l.first == "<" && l.dropLast().dropFirst().filter({$0 == "-"}).count > 0:
133+ small = true
134+ return "⟻"
135+ case let l where l.last == ">" && l.dropLast().filter({$0 == "-"}).count > 0:
136+ small = true
137+ return "⟶"
138+ case let l where l.last == ">" && l.dropLast().filter({$0 == "="}).count > 0:
139+ small = true
140+ return "⟹"
141+ case let l where l.first == "<" && l.dropFirst().filter({$0 == "-"}).count > 0:
142+ small = true
143+ return "⟵"
144+ case let l where l.first == "<" && l.dropFirst().filter({$0 == "="}).count > 0:
145+ small = true
146+ return "⟸"
147+ default:
148+ return el
149+ }
150+ }
151+
152+ func process(lineElement: Substring, withAttributes attributes: String = "", style: ElementStyle = .none) -> Substring {
153+ func extractNextElement(from line: Substring) -> (element: Substring, left: Substring) {
154+ if line.first != "(" {
155+ var i = line.startIndex
156+ var el: Substring = ""
157+ while i < line.endIndex && CharacterSet.alphanumerics.contains(line[i].unicodeScalars.first!) {
158+ el.append(line[i])
159+ i = line.index(after: i)
160+ }
161+ return (el, line[i...])
162+ } else {
163+ var brackets = 0
164+ var i = line.startIndex
165+ var el: Substring = ""
166+ while i < line.endIndex {
167+ switch el[i] {
168+ case "(":
169+ brackets += 1
170+ case ")":
171+ brackets -= 1
172+ default:
173+ break
174+ }
175+ i = line.index(after: i)
176+ if brackets == 0 {
177+ break
178+ }
179+ el.append(el[i])
180+ }
181+ if brackets != 0 {
182+ print("Mismatched brackets")
183+ exit(0)
184+ }
185+ return (el.dropFirst(), line[i...])
186+ }
187+ }
188+ var i = lineElement.startIndex
189+ while i < lineElement.endIndex {
190+ switch lineElement[i] {
191+ case "^":
192+ let parts = extractNextElement(from: lineElement[lineElement.index(after: i)...])
193+ return "<mo mathvariant=\"\(style.rawValue)\" \(attributes)>\(lineElement[..<i].filter({$0 != "\\"}))</mo>" + "<msup><mo></mo><mn>\(parts.element)</mn></msup>" + process(lineElement: parts.left, withAttributes: attributes, style: style)
194+ case "!":
195+ let parts = extractNextElement(from: lineElement[lineElement.index(after: i)...])
196+ return "<mo mathvariant=\"\(style.rawValue)\" \(attributes)>\(lineElement[..<i].filter({$0 != "\\"}))</mo>" + "<mover accent=\"true\"><mrow><mo>\(parts.element)</mo></mrow><mo>_</mo></mover>" + process(lineElement: parts.left, withAttributes: attributes, style: style)
197+ case "\\":
198+ i = lineElement.index(after: i)
199+ case "/":
200+ let parts = extractNextElement(from: lineElement[lineElement.index(after: i)...])
201+ return "<mo mathvariant=\"\(style.rawValue)\" \(attributes)>\(lineElement[..<i].filter({$0 != "\\"}))</mo>" + "<msub><mo></mo><mn>\(parts.element)</mn></msub>" + process(lineElement: parts.left, withAttributes: attributes, style: style)
202+ default:
203+ break
204+ }
205+ i = lineElement.index(after: i)
206+ }
207+ return Substring("<mo mathvariant=\"\(style.rawValue)\" \(attributes)>\(lineElement.filter({$0 != "\\"}))</mo>")
208+ }
209+ func process(line: Substring) {
114210 out.append("<mtr>")
115211 for element in line.split(
116− whereSeparator: {c in whitespace.contains(c.unicodeScalars.first!)}) {
212+ whereSeparator: {c in CharacterSet.whitespaces.contains(c.unicodeScalars.first!)}) {
117213 switch element {
118214 case "_":
119215 out.append("<mtd><mspace height=\"0.8em\"/></mtd>")
120216 default:
121217 let eStyle = element.style
122− out.append("<mtd><mn mathvariant=\"\(eStyle.rawValue)\" height=\"0.8em\">\(element.trimmingStyleCharecters())</mn></mtd>")
218+ out.append("<mtd>\(process(lineElement: Substring(element.trimmingStyleCharecters()), withAttributes: "height=\"0.8em\"", style: eStyle))</mtd>")
123219 }
124220 }
125221 out.append("</mtr>")
126222 }
127− func checkInsideMatrix() {
128− if insideMatrix {
129− if seperated {
130− out.append("</mtable><mo>|</mo><mtable>")
131− for line in afterSeparator {
132− pureProcess(line: line)
133− }
134− }
135− out.append("</mtable><mo>\(style.closing)</mo></mrow>")
136− insideMatrix = false
137− seperated = false
138− afterSeparator = []
139− }
140− }
141− func process(line: String.SubSequence) {
142− switch line {
143− case "":
144− checkInsideMatrix()
145− default:
146− if !insideMatrix {
147− out.append("<mrow><mo>\(style.opening)</mo><mtable>")
148− insideMatrix = true
149− }
150− pureProcess(line: line)
223+ func process(comment: String) {
224+ if comment.hasPrefix("#") {
225+ out.append("<!-- \(comment.trimmingCharacters(in: commentChars).trimmingCharacters(in: .whitespaces)) -->")
151226 }
152−
153227 }
154− for line in lines {
155− if !insideMatrix {
156− if lines.first?.contains("|") == true {
228+
229+ for line in nEl {
230+ if inMatrix {
231+ if first && line.contains("|") {
157232 seperated = true
158233 }
159− }
160− if line == "" {
161− process(line: Substring(line))
162− } else if seperated {
163− let split = line.split(separator: "|", maxSplits: 1, omittingEmptySubsequences: false)
164− if split.count != 2 {
165− print("Inconsistent syntax")
166− exit(0)
234+ switch line {
235+ case "]":
236+ if seperated {
237+ out.append("</mtable><mo stretchy=\"true\">|</mo><mtable>")
238+ for line in afterSeparator {
239+ process(line: line)
240+ }
241+ }
242+ out.append("</mtable><mo stretchy=\"true\">\(style.closing)</mo></mrow></mtd></mtr>")
243+ inMatrix = false
244+ seperated = false
245+ afterSeparator = []
246+ default:
247+ if seperated {
248+ let split = line.split(separator: "|", maxSplits: 1, omittingEmptySubsequences: false)
249+ if split.count != 2 {
250+ print("Inconsistent syntax. The `|` seperator isn't consistent within a matrix.")
251+ exit(0)
252+ }
253+ process(line: split[0])
254+ afterSeparator.append(split[1])
255+ } else {
256+ process(line: Substring(line))
257+ }
167258 }
168− process(line: split[0])
169− afterSeparator.append(split[1])
170259 } else {
171− process(line: Substring(line))
260+ switch line {
261+ case let l where l.hasPrefix("//"):
262+ break
263+ case let l where l.hasPrefix("#"):
264+ out.append("</mtable></math>\n\n")
265+ process(comment: l)
266+ out.append("\n\n<math><mtable>")
267+ break // TODO: Figure out what to do
268+ case "[":
269+ out.append("<mtr><mtd><mrow><mo stretchy=\"true\">\(style.opening)</mo><mtable>")
270+ inMatrix = true
271+ first = true
272+ continue
273+ case "":
274+ if !first {
275+ out.append("</mtable><mtable>")
276+ }
277+ first = true
278+ continue
279+ case let l where arrows.contains(l.first!.unicodeScalars.first!):
280+ out.append("<mtr><mtd><mo>\(line)</mo></mtd></mtr>")
281+ default:
282+ out.append("<mtr><mtd>\(small ? "<mstyle scriptlevel=\"1\">" : "")\(process(lineElement: Substring(line)))\(small ? "</mstyle>" : "")</mtd></mtr>")
283+ }
172284 }
285+ first = false
286+ }
287+ return out
288+}
289+
290+func process(mth: String) -> String {
291+ let elements = mth
292+ .split(separator: "\n", omittingEmptySubsequences: false)
293+ .map({$0.trimmingCharacters(in: .whitespaces)})
294+ .map({ l in
295+ var i = l.startIndex
296+ for u in 0..<max(0, l.count - 1) {
297+ if l[i] == "/" && l[l.index(after: i)] == "/" {
298+ return String(l.dropLast(l.count - u))
299+ }
300+ i = l.index(after: i)
301+ }
302+ return l
303+ })
304+ .split(separator: "")
305+ var out = "<math><mtable>"
306+ for el in elements {
307+ out.append(process(element: Array(el)))
308+ out.append("</mtable><mtable>")
173309 }
174− checkInsideMatrix()
175− out.append("</math>")
310+ out.append("</mtable></math>")
176311 return out
177312}
178313