diff options
| -rw-r--r-- | data/reader.lua | 83 |
1 files changed, 63 insertions, 20 deletions
diff --git a/data/reader.lua b/data/reader.lua index 4aca4edd3..5cc2dfc0c 100644 --- a/data/reader.lua +++ b/data/reader.lua @@ -1,42 +1,85 @@ -- A sample custom reader for a very simple markup language. -- This parses a document into paragraphs separated by blank lines. --- This is _{italic} and this is *{boldface} --- This is an escaped special character: \_, \*, \{, \} +-- This is /italic/ and this is *boldface* and this is `code` +-- and `code``with backtick` (doubled `` = ` inside backticks). +-- This is an escaped special character: \_, \*, \\ -- == text makes a level-2 heading -- That's it! -- For better performance we put these functions in local variables: -local P, S, R, Cf, Cc, Ct, V, Cs, Cg, Cb, B = +local P, S, R, Cf, Cc, Ct, V, Cs, Cg, Cb, B, C, Cmt = lpeg.P, lpeg.S, lpeg.R, lpeg.Cf, lpeg.Cc, lpeg.Ct, lpeg.V, - lpeg.Cs, lpeg.Cg, lpeg.Cb, lpeg.B + lpeg.Cs, lpeg.Cg, lpeg.Cb, lpeg.B, lpeg.C, lpeg.Cmt + +--- if item is a table, concatenate it to acc; +-- otherwise insert it at the end. +local function add_item(acc, item) + if acc == nil then + acc = {} + end + if type(item) == "table" then + for i = 1,#item do + add_item(acc, item[i]) + end + else + acc[#acc + 1] = item + end + return acc +end + +local function Many1(parser) + return Cf(Cc(nil) * parser^1 , add_item) +end + +local function Many(parser) + return (Many1(parser) + Cc{}) +end local whitespacechar = S(" \t\r\n") -local specialchar = S("_*{}\\") -local escapedchar = P"\\" * specialchar - / function (x) return string.sub(x,2) end -local wordchar = (P(1) - (whitespacechar + specialchar)) + escapedchar +local specialchar = S("/*\\`") +local wordchar = (1 - (whitespacechar + specialchar)) local spacechar = S(" \t") local newline = P"\r"^-1 * P"\n" -local blanklines = newline * spacechar^0 * newline^1 +local blanklines = newline * (spacechar^0 * newline)^1 local endline = newline - blanklines +local function BetweenDelims(c, parser, constructor) + local starter = P(c) * #(- whitespacechar) + local ender = B(1 - whitespacechar) * P(c) + return starter * Many(parser - ender) * C(ender^-1) / + function(contents, ender) + if ender == "" then -- fallback + return { pandoc.Str(c) , contents } + else + return constructor(contents) + end + end +end + + -- Grammar G = P{ "Pandoc", - Pandoc = blanklines^-1 * Ct(V"Block"^0) / pandoc.Pandoc; - Block = V"Header" + V"Para"; - Para = Ct(V"Inline"^1) * blanklines^-1 / pandoc.Para; - Header = Ct(Cg(P("=")^1 / function(x) return #x end, "length") + Pandoc = Many(V"Block") / pandoc.Pandoc; + Block = blanklines^0 * (V"Header" + V"Para") ; + Para = Many1(V"Inline") * blanklines^-1 / pandoc.Para; + Header = (P("=")^1 / string.len) * spacechar^1 - * Cg(Ct(V"Inline"^0), "contents") - * blanklines^-1) / - function(res) return pandoc.Header(res.length, res.contents) end; - Inline = V"Emph" + V"Str" + V"Space" + V"SoftBreak" + V"Special" ; + * Many(V"Inline" - (spacechar^0 * P("=")^0 * blanklines)) + * spacechar^0 + * P("=")^0 + * blanklines^-1 / + function(lev, contents) return pandoc.Header(lev, contents) end; + Inline = V"Emph" + V"Strong" + V"Str" + V"Space" + V"SoftBreak" + + V"Code" + V"Escaped" + V"Special"; Str = wordchar^1 / pandoc.Str; + Escaped = "\\" * C(specialchar) / function(s) return pandoc.Str(s) end; Space = spacechar^1 / pandoc.Space; SoftBreak = endline / pandoc.SoftBreak; - Emph = Ct(P"_{" * Cg(Ct((V"Inline" - P"}")^1), "contents") * P"}") / - function(res) return pandoc.Emph(res.contents) end; - Special = specialchar / pandoc.Str; + Emph = BetweenDelims("/", V"Inline", pandoc.Emph); + Strong = BetweenDelims("*", V"Inline", pandoc.Strong); + Code = P"`" * Ct(( (P"``" / "`") + (C(1) - S"`"))^1) * P"`" + / table.concat / pandoc.Code; + Special = S"`\\" / pandoc.Str; } function Reader(input) |