Improve changelog grammar

This PR makes the changelog parser less strict. This includes removing
the requirement for more than one newline after release sections and
allowing entries to be seperated by many newlines.

changelog.pony

@@ -19,22 +19,10 @@ class Changelog
       unreleased = None
     end
 
-  fun ref create_release(version: String, date: String) ? =>
+  fun ref create_release(version: String, date: String) =>
     match unreleased
     | let r: Release =>
       r.heading = "## [" + version + "] - " + date
-
-      if (r.fixed as Section).entries == "" then
-        r.fixed = None
-      end
-      if (r.added as Section).entries == "" then
-        r.added = None
-      end
-      if (r.changed as Section).entries == "" then
-        r.changed = None
-      end
-    else
-      this
     end
 
   fun ref create_unreleased() =>
@@ -58,53 +46,67 @@ class Release
   var added: (Section | None)
   var changed: (Section | None)
 
+  let _unreleased_heading: String = "## [unreleased] - unreleased"
+
   new create(ast: AST) ? =>
-    let t = ast.children(0)? as Token
-    heading = t.source.content.trim(t.offset, t.offset + t.length)
+    heading = (ast.children(0)? as Token).string()
     fixed = try Section(ast.children(1)? as AST)? else None end
     added = try Section(ast.children(2)? as AST)? else None end
     changed = try Section(ast.children(3)? as AST)? else None end
 
   new _unreleased() =>
-    heading = "## [unreleased] - unreleased"
-    fixed = Section._emtpy(Fixed)
-    added = Section._emtpy(Added)
-    changed = Section._emtpy(Changed)
+    heading = _unreleased_heading
+    fixed = Section._empty(Fixed)
+    added = Section._empty(Added)
+    changed = Section._empty(Changed)
 
   fun string(): String iso^ =>
-    let str = recover String .> append(heading) .> append("\n\n") end
-    for section in [fixed; added; changed].values() do
-      match section
-      | let s: this->Section =>
-        str .> append(s.string()) .> append("\n\n")
+    if heading == _unreleased_heading then
+      "\n\n".join(
+        [ heading
+          "### Fixed\n"
+          "### Added\n"
+          "### Changed\n"
+          ""
+        ].values())
+    else
+      let str = recover String .> append(heading) .> append("\n\n") end
+      for section in [fixed; added; changed].values() do
+        match section
+        | let s: Section box =>
+          str .> append(s.string()) .> append("\n")
+        end
       end
+      str
     end
-    str
 
 class Section
   let label: TSection
-  let entries: String
+  embed entries: Array[String]
 
   new create(ast: AST) ? =>
     label = (ast.children(0)? as Token).label() as TSection
-    entries =
-      try
-        let t = ast.children(1)? as Token
-        t.source.content.trim(t.offset, t.offset + t.length)
-      else
-        ""
-      end
+    let es = ast.children(1)? as AST
+    entries = Array[String](es.size())
 
-  new _emtpy(label': TSection) =>
-    (label, entries) = (label', "")
+    for entry in es.children.values() do
+      try entries.push((entry as Token).string()) end
+    end
+
+  new _empty(label': TSection) =>
+    (label, entries) = (label', Array[String])
 
-  fun is_empty(): Bool => entries == ""
+  fun is_empty(): Bool => entries.size() == 0
 
   fun string(): String =>
+    let entries' = recover String end
+    for entry in entries.values() do
+      entries'.append(entry)
+    end
     recover
       String
         .> append("### ")
         .> append(label.text())
         .> append("\n\n")
-        .> append(entries)
+        .> append(consume entries')
     end

changelog_parser.pony

@@ -8,7 +8,7 @@ primitive ChangelogParser
 
   fun head(): Parser val =>
     recover
-      (not L("\n## [") * Unicode).many().term(THeading)
+      (not L("\n## [") * Unicode).many().term()
         * -L("\n").opt()
     end
 
@@ -32,9 +32,10 @@ primitive ChangelogParser
       let heading = (L("### ") * L(s.text())).term(s)
       let entries' =
         if released then entries()
-        else entries().opt() // allow empty sections in unreleased
+        // allow empty sections in unreleased
+        else entries().opt()
         end
-      heading * -L("\n\n") * entries' * -L("\n").many1()
+      (heading * -L("\n").many() * entries').node(NoLabel)
     end
 
   fun version(): Parser val =>
@@ -50,19 +51,19 @@ primitive ChangelogParser
       (digits4 * L("-") * digits2 * L("-") * digits2).term(TDate)
     end
 
-  // TODO parse entries individually
   fun entries(): Parser val =>
     recover
-      let chars = R(' ').many1()
-      (L("- ") * chars * (L("\n") * chars).many()).term(TEntries)
+      let line = Forward
+      line() = L("\n") / (Unicode * line)
+      let sep = L("-") / L("#") / L("\n")
+      let entry = L("- ") * line * (not sep * line).many()
+      (entry.term(TEntry) * -L("\n").many()).many1().node(TEntries)
     end
 
   fun digits(): Parser val => recover digit().many1() end
 
   fun digit(): Parser val => recover R('0', '9') end
 
-primitive THeading is Label fun text(): String => "Heading"
-
 trait val TSection is Label
 primitive Fixed is TSection fun text(): String => "Fixed"
 primitive Added is TSection fun text(): String => "Added"
@@ -72,3 +73,4 @@ primitive TRelease is Label fun text(): String => "Release"
 primitive TVersion is Label fun text(): String => "Version"
 primitive TDate is Label fun text(): String => "Date"
 primitive TEntries is Label fun text(): String => "Entries"
+primitive TEntry is Label fun text(): String => "Entry"

changelog_tool.pony

@@ -13,7 +13,14 @@ class ChangelogTool
   fun verify() =>
     _env.out.print("verifying " + _filename + "...")
     try
-      _parse()?
+      let ast = _parse()?
+
+      // TODO:
+      // let changelog = Changelog(ast)?
+      // _env.out.print(changelog.string())
+      // try changelog .> create_release("0.0.0", "0000-00-00")
+      // else _env.out.print("fail.")
+      // end
       _env.out.print(_filename + " is a valid changelog")
     end
 
@@ -23,7 +30,7 @@ class ChangelogTool
       let date = Date(Time.seconds()).format("%Y-%m-%d")
       let changelog: String =
         Changelog(_parse()?)?
-          .> create_release(version, date)?
+          .> create_release(version, date)
           .string()
       _edit_or_print(edit, changelog)
     else

tests/CHANGELOG.md

@@ -7,15 +7,12 @@ All notable changes to the Pony compiler and standard library will be documented
 ### Fixed
 
 
-
 ### Added
 
 
-
 ### Changed
 
 
-
 ## [0.13.0] - 2017-04-07
 
 ### Fixed