Make rule of 2-spaces to preserve a line break universal

It's now in the wrapping code and taken out of each parser.

This does though mean that things won't be treated as separate
paragraphs from the point-of-view of what to wrap with an empty
selection.

core/Parsers_Markdown.fs

@@ -26,7 +26,7 @@ let private mdMarker marker = regex (@"^ {0,3}" + marker)
 
 /// The default paragraph type (fallback for if no other parser matches)
 let private defaultPara (_ctx: Context) : FirstLineParser =
-  let lineBreakEnd = regex @"(\\|\s{2}|<br/?>)$"
+  let lineBreakEnd = regex @"(\\|<br/?>)$"
   let rec parseLine (line: Line) : FirstLineRes =
     // We assume a >3 space indent on the first line would have already been
     // picked up by another parser, so it's ok to just trim all indent

core/Parsing.DocComments.fs

@@ -105,9 +105,7 @@ let ddoc =
 let godoc settings =
     let indentedLines =
         ignoreParser (Nonempty.span (fun line -> line.[0] = ' ' || line.[0] = '\t'))
-    let textLines =
-        splitIntoChunks (afterRegex (Regex("  $"))) >> map (Wrap << Wrappable.fromLines ("", ""))
-
+    let textLines = Nonempty.singleton << Wrap << Wrappable.fromLines ("", "")
     textLines
         |> takeUntil (tryMany [blankLines; indentedLines])
         |> repeatToEnd

core/Parsing.Documents.fs

@@ -17,7 +17,6 @@ open Parsing_SourceCode
 let oldPlainText settings =
   let paragraphs =
       splitIntoChunks (onIndent settings.tabWidth)
-          >> Nonempty.concatMap (splitIntoChunks (afterRegex (Regex("  $"))))
           >> map (indentSeparatedParagraphBlock textBlock)
 
   takeUntil blankLines paragraphs |> repeatToEnd

core/Parsing.Latex.fs

@@ -14,8 +14,7 @@ let private markdown = Parsing.Markdown.markdown
 let private newlineRegex: Regex =
     Regex
         ( @"(\\(\\\*?|hline|newline|break|linebreak)(\[.*?\])?(\{.*?\})?\s*$)"
-        + @"|  $|"
-        + @"([^\\]%)"
+        + @"|([^\\]%)"
         )
 
 /// Commands that, when starting a line, should always preserve the line break

core/Parsing.Sgml.fs

@@ -69,7 +69,7 @@ let sgml
 
     let breakBefore line = justBlockEndTag line || beginsWithBlockStartTag line
     let breakAfter line =
-        Line.contains (regex @"([""\s]>\s*|  )$") line || endsWithBlockTag line
+        Line.contains (regex @"([""\s]>\s*)$") line || endsWithBlockTag line
 
     let paragraphBlocks =
         splitIntoChunks (splitBefore breakBefore)

core/Wrapping.fs

@@ -37,7 +37,7 @@ let canBreakBetweenChars c1 c2 =
 
 /// When concatenating lines before breaking up again, whether to add a space
 /// between chars
-let addSpaceBetweenChars c1 c2 = if isCJ c1 || isCJ c2 then false else true
+let addSpaceBetweenChars c1 c2 = if c1 = 10us || isCJ c1 || isCJ c2 then false else true
 
 
 /// Concatenates lines into a single string, adding the right amount of
@@ -47,10 +47,9 @@ let concatLines doubleSentenceSpacing lines =
   let addLine (acc: string) (line: string) =
     // Shouldn't be getting empty strings in this function but just in case...
     if line = String.Empty || acc = String.Empty then acc else
-    let acc = acc.TrimEnd()
+    let acc = if acc.EndsWith("  ") then acc + "\n" else acc.TrimEnd()
     let accEnd = uint16 acc.[acc.Length-1]
-    let space =
-      if doubleSentenceSpacing && Array.contains accEnd stops then "  " else " "
+    let space = if doubleSentenceSpacing && Array.contains accEnd stops then "  " else " "
     if addSpaceBetweenChars accEnd (uint16 line.[0]) then acc + space + line else acc + line
   List.reduce addLine (Nonempty.toList lines)
 
@@ -76,7 +75,9 @@ let breakUpString addLine tabWidth maxWidth (str: string) =
   let outputLine prefixes pStart pEnd =
     let prefix, nextPrefixes = popOrPeek prefixes
     let content =
-      if pEnd > pStart then str.Substring(pStart, pEnd - pStart).Trim()
+      if pEnd > pStart then
+        if str[pEnd-1] = '\n' then str.Substring(pStart, pEnd - pStart - 1)
+        else str.Substring(pStart, pEnd - pStart).TrimEnd()
       else str.Substring(pStart)
     addLine (prefix + content.Replace('\000', ' '))
     nextPrefixes
@@ -87,6 +88,11 @@ let breakUpString addLine tabWidth maxWidth (str: string) =
     if pStr >= str.Length then outputLine prefixes lineStart 0 |> ignore
     else
     let charCode = uint16 str.[pStr]
+    // If we come across a LF char then start a new line
+    if charCode = 10us then
+      let nextPrefixes = outputLine prefixes lineStart (pStr+1)
+      loop nextPrefixes (pStr+1) (prefixWidth nextPrefixes) (pStr+1)
+    else
     let newWidth = curWidth + Line.charWidth tabWidth curWidth charCode
     // If current char is whitespace we don't need to wrap yet. Wait until we come across
     // a non-whitespace char

docs/specs/features/spaces.md

@@ -23,7 +23,7 @@ wrapping column.
 ## At the end of a line
 
 Two spaces at the end of a line preserves the line break after it. This comes
-from Markdown should work for any content.
+from Markdown and should work for any content.
 
 > language: "plaintext"
 
@@ -64,3 +64,9 @@ from Markdown should work for any content.
     Baz foo     ¦            Baz foo bar ¦
     bar baz.    ¦            baz.        ¦
     #>          ¦            #>          ¦
+
+> language: "rst"
+
+    Foo bar.··  ¦    ->      Foo bar.··  ¦
+    Baz foo     ¦            Baz foo bar ¦
+    bar baz.    ¦            baz.        ¦