[feat] support horizontal rule

README.md

@@ -12,7 +12,7 @@ A [Markdown](https://www.markdownguide.org/) parser for idris2
 - [ ] Blockquote
 - [ ] Unordered List
 - [ ] Ordered List
-- [ ] Horizontal Rule
+- [x] Horizontal Rule
 - [ ] Image
 
 ## Extended Syntax

src/Language/Markdown/Data.idr

@@ -6,7 +6,7 @@ import Data.List
 
 -- 行内元素
 public export
-data Inline = MBold String | MBare String | MCode String | MItalic String
+data Inline = MBold String | MBare String | MCode String | MItalic String 
 
 public export
 Show Inline where
@@ -25,17 +25,21 @@ Eq Inline where
 
 -- 块级元素
 public export
-data Block = MLine (List Inline) | MHeading Int (List Inline)
+data Block = MLine (List Inline) | MHeading Int (List Inline) | MHorizontal | MSpaceLine
 
 public export
 Show Block where
   show (MLine s) = "MLine(" ++ show s ++ ")"
   show (MHeading n s) = "MHeading " ++ show n ++ " (" ++ show s ++ ")"
+  show MHorizontal = "MHorizontal"
+  show MSpaceLine = "MSpaceLine"
 
 export
 Eq Block where
   (MLine x) == (MLine y) =  x == y
   (MHeading s x) == (MHeading t y) =  s == t && x == y 
+  MHorizontal == MHorizontal = True
+  MSpaceLine == MSpaceLine = True
   _ == _ = False
 
 public export

src/Language/Markdown/Lexer.idr

@@ -50,11 +50,12 @@ markdownTokenMap : TokenMap MarkdownToken
 markdownTokenMap = toTokenMap [
   (multNewLine,  MKBreak),
   (spaceLineBreak,  MKBreak),
-  -- (code, MKCode),
+  (newline,  MKSoftBreak),
   (is ' ', MKSpace),
   (is '#', MKNumberSign),
   (is '*', MKAsterisk),
   (is '_', MKUnderline),
+  (is '-', MKDash),
   (is '`', MKBackQuote),
   (any, MKText)
 ]

src/Language/Markdown/Parser.idr

@@ -3,6 +3,8 @@ module Language.Markdown.Parser
 import Language.Markdown.Data
 import Text.Parser
 import Data.List
+import Data.Nat
+
 
 import public Language.Markdown.Tokens
 
@@ -26,22 +28,38 @@ mergeBare : List Inline -> List Inline
 mergeBare = foldr consBare []
 
 private
-isT : Token MarkdownTokenKind -> Bool
-isT (Tok MKAsterisk _) = True
-isT _ = True
+softbreak : Grammar state MarkdownToken True String
+softbreak = do
+  match MKSoftBreak
+  pure " "
+
+-- 水平线
+private
+horizontal : Grammar state MarkdownToken (isSucc (min (atLeast 3)) || Delay True) Block
+horizontal = do
+  _ <- many $ match MKSpace
+  _ <- count (atLeast 3) $ match MKDash
+  _ <- many $ match MKSpace
+  maybeNewline <|> match MKSoftBreak
+  pure $ MHorizontal
+
+spaceLine : Grammar state MarkdownToken True Block
+spaceLine = do 
+  _ <- some $ match MKBreak
+  pure $ MSpaceLine
 
 mutual
   private
   document : Grammar state MarkdownToken True Markdown
   document = do
-    vals <- some (heading <|> line)
+    vals <- some (heading <|> horizontal <|> line <|> spaceLine)
     pure $ MDoc $ forget vals
 
   textNumberSign : Grammar state MarkdownToken True Inline
   textNumberSign = pure $ MBare !(match MKNumberSign)
 
   textSpace : Grammar state MarkdownToken True Inline
-  textSpace = pure $ MBare !(match MKSpace)
+  textSpace = pure $ MBare !(match MKSpace <|> softbreak)
 
   private
   heading : Grammar state MarkdownToken True Block
@@ -112,7 +130,7 @@ mutual
     pure $ MBare "**"
 
   bare : Grammar state MarkdownToken True Inline
-  bare = do vals <- some $ (match MKText <|> match MKSpace)
+  bare = do vals <- some $ (match MKText <|> match MKSpace <|> match MKDash)
             pure $ MBare $ concat1 vals
 
 export

src/Language/Markdown/Tokens.idr

@@ -10,10 +10,10 @@ data MarkdownTokenKind
   | MKText
   | MKSpace
   | MKBreak
+  | MKSoftBreak
   | MKBackQuote
   | MKUnderline
-  | MKCode
-  | MKItalic
+  | MKDash
 
 public export
 Eq MarkdownTokenKind where
@@ -22,10 +22,10 @@ Eq MarkdownTokenKind where
   (==) MKText MKText = True
   (==) MKSpace MKSpace = True
   (==) MKBreak MKBreak = True
+  (==) MKSoftBreak MKSoftBreak = True
   (==) MKBackQuote MKBackQuote = True
   (==) MKUnderline MKUnderline = True
-  (==) MKCode MKCode = True
-  (==) MKItalic MKItalic = True
+  (==) MKDash MKDash = True
   (==) _ _ = False
 
 public export
@@ -35,16 +35,15 @@ Show MarkdownTokenKind where
   show MKText = "MKText"
   show MKSpace = "MKSpace"
   show MKBreak = "MKBreak"
+  show MKSoftBreak = "MKSoftBreak"
   show MKBackQuote = "MKBackQuote"
   show MKUnderline = "MKUnderline"
-  show MKCode = "MKCode"
-  show MKItalic = "MKCode"
+  show MKDash = "MKDash"
 
 public export
 TokenKind MarkdownTokenKind where
   TokType MKText = String
-  TokType MKCode = String
-  TokType MKItalic = String
+  TokType MKDash = String
   TokType MKSpace = String
   TokType MKAsterisk = String
   TokType MKBackQuote = String
@@ -55,10 +54,10 @@ TokenKind MarkdownTokenKind where
   tokValue MKNumberSign _ = "#"
   tokValue MKAsterisk _ = "*"
   tokValue MKText s = s
-  tokValue MKCode s = strSubstr 1 ((strLength s) - 2) s
-  tokValue MKItalic s = strSubstr 1 ((strLength s) - 2) s
+  tokValue MKDash _ = "-"
   tokValue MKSpace _ = " "
   tokValue MKBreak _ = ()
+  tokValue MKSoftBreak _ = ()
   tokValue MKBackQuote _ = "`"
   tokValue MKUnderline _ = "_"
 

test/src/Test/Parser.idr

@@ -67,9 +67,23 @@ testItalic = [
     , test "测试标题中斜体" $ assertBlocks "## 我是*斜体*" [MHeading 2 [MBare "我是", MItalic "斜体"]]
 ]
 
+-- 测试行内代码
+private
+testHor : List Test
+testHor = [
+    test "测试水平线" $ assertBlocks "---" [MHorizontal]
+    , test "测试水平线加空格" $ assertBlocks "---     " [MHorizontal]
+    , test "测试水平线加后空行" $ assertBlocks "---\n" [MHorizontal]
+    , test "测试水平线加前软换行" $ assertBlocks "\n---" [MLine [MBare " ---"]]
+    , test "测试水平线加前硬换行" $ assertBlocks "\n\n---" [MSpaceLine, MHorizontal]
+    , test "测试水平线加前空格" $ assertBlocks "  ---" [MHorizontal]
+    , test "测试水平线多加-" $ assertBlocks "-------  " [MHorizontal]
+    , test "测试水平线加后字符" $ assertBlocks "---abcd" [MLine [MBare "---abcd"]]
+]
+
 export 
 testParser : List Test
-testParser = testHeading ++ testBold ++ testCode ++ testItalic
+testParser = testHeading ++ testBold ++ testCode ++ testItalic ++ testHor
 
 
 private