From cf17f5ac7c2b7a419bbbfc7ae2105628b9a0ac3d Mon Sep 17 00:00:00 2001
From: Peter Donovan <peterdonovan@berkeley.edu>
Date: Tue, 20 Jun 2023 12:03:01 -0700
Subject: [PATCH] Make handling of comments more conservative.

Also, handle ``` ``` preformatted blocks.
---
 .../java/org/lflang/ast/FormattingUtil.java   | 54 ++++++++++---------
 1 file changed, 29 insertions(+), 25 deletions(-)

diff --git a/core/src/main/java/org/lflang/ast/FormattingUtil.java b/core/src/main/java/org/lflang/ast/FormattingUtil.java
index 7eb7069ef2..0c594bd0b0 100644
--- a/core/src/main/java/org/lflang/ast/FormattingUtil.java
+++ b/core/src/main/java/org/lflang/ast/FormattingUtil.java
@@ -127,27 +127,31 @@ static String lineWrapComments(List<String> comments, int width, String singleLi
   }
   /** Wrap lines. Do not merge lines that start with weird characters. */
   private static String lineWrapComment(String comment, int width, String singleLineCommentPrefix) {
+    if (!MULTILINE_COMMENT.matcher(comment).matches()) return comment;
     width = Math.max(width, MINIMUM_COMMENT_WIDTH_IN_COLUMNS);
-    List<List<String>> paragraphs =
-        Arrays.stream(
-                comment
-                    .strip()
-                    .replaceAll("^/?((\\*|//|#)\\s*)+", "")
-                    .replaceAll("\\s*\\*/$", "")
-                    .replaceAll("(?<=(\\r\\n|\\r|\\n))\\h*(\\*|//|#)\\h*", "")
-                    .split("(\n\\s*){2,}"))
+    var stripped = comment
+            .strip()
+            .replaceAll("^/?((\\*|//|#)\\s*)+", "")
+            .replaceAll("\\s*\\*/$", "")
+            .replaceAll("(?<=(\\r\\n|\\r|\\n))\\h*(\\*|//|#)\\h?(\\h*)", "$3");
+    var preformatted = false;
+    StringBuilder result = new StringBuilder(stripped.length() * 2);
+    for (var part : stripped.split("```")) {
+      result.append(
+              preformatted ? part.lines().skip(1).map(it -> " * " + it).collect(Collectors.joining("\n", "\n * ```\n", "\n * ```\n"))
+                      : lineWrapComment(
+                              Arrays.stream(part.split("(\n\\s*){2,}"))
             .map(s -> Arrays.stream(s.split("(\\r\\n|\\r|\\n)\\h*(?=[@#$%^&*\\-+=:;<>/])")))
-            .map(stream -> stream.map(s -> s.replaceAll("\\s+", " ")))
-            .map(Stream::toList)
-            .toList();
-    if (MULTILINE_COMMENT.matcher(comment).matches()) {
-      if (paragraphs.size() == 1 && paragraphs.get(0).size() == 1) {
-        String singleLineRepresentation = String.format("/** %s */", paragraphs.get(0).get(0));
-        if (singleLineRepresentation.length() <= width) return singleLineRepresentation;
-      }
-      return String.format("/**\n%s\n */", lineWrapComment(paragraphs, width, " * "));
+              .map(stream -> stream.map(s -> s.replaceAll("\\s+", " ")))
+              .map(Stream::toList)
+              .toList(), width, " * "));
+      preformatted = !preformatted;
+    }
+    if (result.indexOf("\n") == -1) {
+      String singleLineRepresentation = String.format("/** %s */", result.substring(result.indexOf(" * ") + 3));
+      if (singleLineRepresentation.length() <= width) return singleLineRepresentation;
     }
-    return lineWrapComment(paragraphs, width, singleLineCommentPrefix + " ");
+    return String.format("/**\n%s\n */", result);
   }
 
   /**
@@ -158,15 +162,15 @@ private static String lineWrapComment(String comment, int width, String singleLi
    * @param linePrefix A string to prepend to each line of comment.
    */
   private static String lineWrapComment(
-      List<List<String>> paragraphs, int width, String linePrefix) {
+          List<List<String>> paragraphs, int width, String linePrefix) {
     int widthAfterPrefix = Math.max(width - linePrefix.length(), MINIMUM_COMMENT_WIDTH_IN_COLUMNS);
     return paragraphs.stream()
-        .map(
-            paragraph ->
-                wrapLines(paragraph, widthAfterPrefix)
-                    .map(s -> (linePrefix + s.stripLeading()).stripTrailing())
-                    .collect(Collectors.joining("\n")))
-        .collect(Collectors.joining(String.format("\n%s\n", linePrefix.stripTrailing())));
+            .map(
+                    paragraph ->
+                            wrapLines(paragraph, widthAfterPrefix)
+                                    .map(s -> (linePrefix + s.stripLeading()).stripTrailing())
+                                    .collect(Collectors.joining("\n")))
+            .collect(Collectors.joining(String.format("\n%s\n", linePrefix.stripTrailing())));
   }
 
   /** Wrap a given paragraph. */