Expose Doc constructors and combinators

Author: tarleb

src/Foreign/Lua/Module/DocLayout.hs

@@ -19,6 +19,33 @@ module Foreign.Lua.Module.DocLayout (
     pushModule
   , preloadModule
 
+  -- * Doc constructors and combinators
+  , after_break
+  , before_non_blank
+  , blankline
+  , blanklines
+  , braces
+  , brackets
+  , cblock
+  , chomp
+  , cr
+  , double_quotes
+  , empty
+  , flush
+  , hang
+  , inside
+  , lblock
+  , literal
+  , nest
+  , nestle
+  , nowrap
+  , parens
+  , prefixed
+  , quotes
+  , rblock
+  , space
+  , vfill
+
   -- * Functions
   , render
 
@@ -33,6 +60,7 @@ import Foreign.Lua (Lua, NumResults (..), Optional,
                     Peekable, Pushable, StackIndex)
 import Text.DocLayout (Doc)
 
+import qualified Data.Text as T
 import qualified Foreign.Lua as Lua
 import qualified Foreign.Lua.Types.Peekable as Lua
 import qualified Foreign.Lua.Userdata as Lua
@@ -46,7 +74,33 @@ import qualified Text.DocLayout as Doc
 pushModule :: Lua NumResults
 pushModule = do
   Lua.newtable
-  Lua.addfield "empty_doc" (Doc.empty :: Doc Text)
+  -- constructors
+  Lua.addfield "empty"     empty
+  Lua.addfield "blankline" blankline
+  Lua.addfield "cr"        cr
+  Lua.addfield "space"     space
+  Lua.addfunction "after_break" after_break
+  Lua.addfunction "before_non_blank" before_non_blank
+  Lua.addfunction "blanklines" blanklines
+  Lua.addfunction "braces"     braces
+  Lua.addfunction "brackets"   brackets
+  Lua.addfunction "cblock"     cblock
+  Lua.addfunction "chomp"      chomp
+  Lua.addfunction "double_quotes" double_quotes
+  Lua.addfunction "flush"      flush
+  Lua.addfunction "hang"       hang
+  Lua.addfunction "inside"     inside
+  Lua.addfunction "lblock"     lblock
+  Lua.addfunction "literal"    literal
+  Lua.addfunction "nest"       nest
+  Lua.addfunction "nestle"     nestle
+  Lua.addfunction "nowrap"     nowrap
+  Lua.addfunction "parens"     parens
+  Lua.addfunction "quotes"     quotes
+  Lua.addfunction "prefixed"   prefixed
+  Lua.addfunction "rblock"     rblock
+  Lua.addfunction "vfill"      vfill
+  -- renderign
   Lua.addfunction "render" render
   return 1
 
@@ -61,6 +115,115 @@ preloadModule = flip Lua.preloadhs pushModule
 render :: Doc Text -> Optional Int -> Lua Text
 render doc optLength = return $ Doc.render (Lua.fromOptional optLength) doc
 
+--
+-- Constructors
+--
+
+-- | Creates a @'Doc'@ which is conditionally included only if it
+-- comes at the beginning of a line.
+after_break :: Text -> Lua (Doc Text)
+after_break = return . Doc.afterBreak
+
+-- | Conditionally includes the given @'Doc'@ unless it is
+-- followed by a blank space.
+before_non_blank :: Doc Text -> Lua (Doc Text)
+before_non_blank = return . Doc.beforeNonBlank
+
+-- | Inserts a blank line unless one exists already.
+blankline :: Doc Text
+blankline = Doc.blankline
+
+-- | Insert blank lines unless they exist already.
+blanklines :: Int -> Lua (Doc Text)
+blanklines = return . Doc.blanklines
+
+-- | Puts a @'Doc'@ in curly braces.
+braces :: Doc Text -> Lua (Doc Text)
+braces = return . Doc.braces
+
+-- | Puts a @'Doc'@ in square brackets.
+brackets :: Doc Text -> Lua (Doc Text)
+brackets = return . Doc.brackets
+
+-- | Like @'lblock'@ but aligned centered.
+cblock :: Int -> Doc Text -> Lua (Doc Text)
+cblock width = return . Doc.cblock width
+
+-- | Chomps trailing blank space off of a @'Doc'@.
+chomp :: Doc Text -> Lua (Doc Text)
+chomp = return . Doc.chomp
+
+-- | A carriage return. Does nothing if we're at the beginning of
+-- a line; otherwise inserts a newline.
+cr :: Doc Text
+cr = Doc.cr
+
+-- | Wraps a @'Doc'@ in double quotes
+double_quotes :: Doc Text -> Lua (Doc Text)
+double_quotes = return . Doc.doubleQuotes
+
+-- | The empty document.
+empty :: Doc Text
+empty = Doc.empty
+
+-- | Makes a @'Doc'@ flush against the left margin.
+flush :: Doc Text -> Lua (Doc Text)
+flush = return . Doc.flush
+
+-- | Creates a hanging indent.
+hang :: Int -> Doc Text -> Doc Text -> Lua (Doc Text)
+hang ind start doc = return $ Doc.hang ind start doc
+
+-- | Encloses a @'Doc'@ inside a start and end @'Doc'@.
+inside :: Doc Text -> Doc Text -> Doc Text -> Lua (Doc Text)
+inside start end contents = return $ Doc.inside start end contents
+
+-- | Creates a block with the given width and content, aligned to the left.
+lblock :: Int -> Doc Text -> Lua (Doc Text)
+lblock width = return . Doc.lblock width
+
+-- | Creates a @'Doc'@ from a string.
+literal :: Text -> Lua (Doc Text)
+literal = return . Doc.literal
+
+-- | Indents a @'Doc' by the specified number of spaces.
+nest :: Int -> Doc Text -> Lua (Doc Text)
+nest ind = return . Doc.nest ind
+
+-- | Removes leading blank lines from a @'Doc'@.
+nestle :: Doc Text -> Lua (Doc Text)
+nestle = return . Doc.nestle
+
+-- | Makes a @'Doc'@ non-reflowable.
+nowrap :: Doc Text -> Lua (Doc Text)
+nowrap = return . Doc.nowrap
+
+-- | Puts a @'Doc'@ in parentheses.
+parens :: Doc Text -> Lua (Doc Text)
+parens = return . Doc.parens
+
+-- | Uses the specified string as a prefix for every line of the
+-- inside document (except the first, if not at the beginning of
+-- the line).
+prefixed :: Text -> Doc Text -> Lua (Doc Text)
+prefixed prefix = return . Doc.prefixed (T.unpack prefix)
+
+-- | Wraps a @'Doc'@ in single quotes.
+quotes :: Doc Text -> Lua (Doc Text)
+quotes = return . Doc.quotes
+
+-- | Like @'lblock'@ but aligned to the right.
+rblock :: Int -> Doc Text -> Lua (Doc Text)
+rblock ind = return . Doc.rblock ind
+
+-- | A breaking (reflowable) space.
+space :: Doc Text
+space = Doc.space
+
+vfill :: Text -> Lua (Doc Text)
+vfill = return . Doc.vfill
+
+
 --
 -- Marshaling
 --

test/test-doclayout.lua

@@ -10,16 +10,25 @@ local assert = tasty.assert
 
 -- Check existence static fields
 return {
-  group 'static fields' {
-    test('empty_doc', function ()
-      assert.are_equal(type(doclayout.empty_doc), 'userdata')
+  group 'constructors' {
+    test('empty', function ()
+      assert.are_equal(type(doclayout.empty), 'userdata')
+    end),
+    test('blankline', function ()
+      assert.are_equal(type(doclayout.blankline), 'userdata')
+    end),
+    test('cr', function ()
+      assert.are_equal(type(doclayout.cr), 'userdata')
+    end),
+    test('space', function ()
+      assert.are_equal(type(doclayout.space), 'userdata')
     end),
   },
 
   group 'functions' {
     group 'render' {
       test('empty doc', function ()
-        assert.are_equal(doclayout.render(doclayout.empty_doc), '')
+        assert.are_equal(doclayout.render(doclayout.empty), '')
       end)
     }
   },