Add support for block comments.

examples/fib.pork

@@ -1,3 +1,4 @@
+/* fibonacci sequence */
 fib = { n in
   if n == 0
     then 0

examples/syntax.pork

@@ -1,3 +1,4 @@
+/* main function */
 main = { in
   three = 3
   two = 2

src/main/kotlin/gay/pizza/pork/parse/PorkParser.kt

@@ -3,7 +3,7 @@ package gay.pizza.pork.parse
 import gay.pizza.pork.ast.nodes.*
 
 class PorkParser(source: PeekableSource<Token>) {
-  private val whitespaceIncludedSource = source
+  private val unsanitizedSource = source
 
   private fun readIntLiteral(): IntLiteral {
     val token = expect(TokenType.IntLiteral)
@@ -176,8 +176,8 @@ class PorkParser(source: PeekableSource<Token>) {
 
   private fun next(): Token {
     while (true) {
-      val token = whitespaceIncludedSource.next()
+      val token = unsanitizedSource.next()
-      if (token.type == TokenType.Whitespace) {
+      if (ignoredByParser(token.type)) {
         continue
       }
       return token
@@ -186,12 +186,18 @@ class PorkParser(source: PeekableSource<Token>) {
 
   private fun peek(): Token {
     while (true) {
-      val token = whitespaceIncludedSource.peek()
+      val token = unsanitizedSource.peek()
-      if (token.type == TokenType.Whitespace) {
+      if (ignoredByParser(token.type)) {
-        whitespaceIncludedSource.next()
+        unsanitizedSource.next()
         continue
       }
       return token
     }
   }
+
+  private fun ignoredByParser(type: TokenType): Boolean = when (type) {
+    TokenType.BlockComment -> true
+    TokenType.Whitespace -> true
+    else -> false
+  }
 }

src/main/kotlin/gay/pizza/pork/parse/PorkTokenizer.kt

@@ -51,11 +51,39 @@ class PorkTokenizer(val source: CharSource) {
     return Token(TokenType.Whitespace, tokenStart, whitespace)
   }
 
+  private fun readBlockComment(firstChar: Char): Token {
+    val comment = buildString {
+      append(firstChar)
+      var endOfComment = false
+      while (true) {
+        val char = source.next()
+        append(char)
+
+        if (endOfComment) {
+          if (char != '/') {
+            endOfComment = false
+            continue
+          }
+          break
+        }
+
+        if (char == '*') {
+          endOfComment = true
+        }
+      }
+    }
+    return Token(TokenType.BlockComment, tokenStart, comment)
+  }
+
   fun next(): Token {
     while (source.peek() != CharSource.NullChar) {
       tokenStart = source.currentIndex
       val char = source.next()
 
+      if (char == '/' && source.peek() == '*') {
+        return readBlockComment(char)
+      }
+
       for (item in TokenType.SingleChars) {
         val itemChar = item.singleChar!!.char
         if (itemChar != char) {

src/main/kotlin/gay/pizza/pork/parse/TokenType.kt

@@ -26,6 +26,7 @@ enum class TokenType(vararg properties: TokenTypeProperty) {
   Then(Keyword("then")),
   Else(Keyword("else")),
   Whitespace,
+  BlockComment,
   EndOfFile;
 
   val promotions: List<Promotion> = properties.filterIsInstance<Promotion>()