9e6b9cd · typeable/pandoc

git.iko.soy/typeable/pandoc

LaTeX reader: Support `\let`.

Also, fix regular macros so they're expanded at the point of use, and NOT also the point of definition. `\let` macros, by contrast, are expanded at the point of definition. Added an `ExpansionPoint` field to `Macro` to track this difference.

commit9e6b9cdc5face62842cfee6a0eacefed82973239 authorJohn MacFarlane <jgm@berkeley.edu> dateMon 7 Aug 2017, 13:38 (9 years ago) parent3504915

3 files changed+56−14

compare with master

unifiedsplit

src/Text/Pandoc/Readers/LaTeX.hs+28−13 src/Text/Pandoc/Readers/LaTeX/Types.hs+5−1 test/command/macros.md+23

src/Text/Pandoc/Readers/LaTeX.hs+28−13

@@ -65,7 +65,7 @@ import Text.Pandoc.Parsing hiding (many, optional, withRaw,

6565 mathInline, mathDisplay,

6666 space, (<|>), spaces, blankline)

6767import Text.Pandoc.Shared

68−import Text.Pandoc.Readers.LaTeX.Types (Macro(..), Tok(..),

68+import Text.Pandoc.Readers.LaTeX.Types (Macro(..), ExpansionPoint(..), Tok(..),

6969 TokType(..))

7070import Text.Pandoc.Walk

7171import Text.Pandoc.Error (PandocError(PandocParsecError, PandocMacroLoop))

@@ -375,7 +375,7 @@ doMacros n = do

375375 macros <- sMacros <$> getState

376376 case M.lookup name macros of

377377 Nothing -> return ()

378− Just (Macro numargs optarg newtoks) -> do

378+ Just (Macro expansionPoint numargs optarg newtoks) -> do

379379 setInput ts

380380 let getarg = spaces >> braced

381381 args <- case optarg of

@@ -389,9 +389,12 @@ doMacros n = do

389389 addTok t acc = setpos spos t : acc

390390 ts' <- getInput

391391 setInput $ foldr addTok ts' newtoks

392− if n > 20 -- detect macro expansion loops

393− then throwError $ PandocMacroLoop (T.unpack name)

394− else doMacros (n + 1)

392+ case expansionPoint of

393+ ExpandWhenUsed ->

394+ if n > 20 -- detect macro expansion loops

395+ then throwError $ PandocMacroLoop (T.unpack name)

396+ else doMacros (n + 1)

397+ ExpandWhenDefined -> return ()

395398

396399setpos :: (Line, Column) -> Tok -> Tok

397400setpos spos (Tok _ tt txt) = Tok spos tt txt

@@ -1375,7 +1378,8 @@ isBlockCommand s =

13751378

13761379treatAsBlock :: Set.Set Text

13771380treatAsBlock = Set.fromList

1378− [ "newcommand", "renewcommand"

1381+ [ "let"

1382+ , "newcommand", "renewcommand"

13791383 , "newenvironment", "renewenvironment"

13801384 , "providecommand", "provideenvironment"

13811385 -- newcommand, etc. should be parsed by macroDef, but we need this

@@ -1517,7 +1521,7 @@ macroDef :: PandocMonad m => LP m Blocks

15171521macroDef = do

15181522 mempty <$ ((commandDef <|> environmentDef) <* doMacros 0)

15191523 where commandDef = do

1520− (name, macro') <- newcommand

1524+ (name, macro') <- newcommand <|> letmacro

15211525 guardDisabled Ext_latex_macros <|>

15221526 updateState (\s -> s{ sMacros = M.insert name macro' (sMacros s) })

15231527 environmentDef = do

@@ -1532,6 +1536,15 @@ macroDef = do

15321536 -- @\newcommand{\envname}[n-args][default]{begin}@

15331537 -- @\newcommand{\endenvname}@

15341538

1539+letmacro :: PandocMonad m => LP m (Text, Macro)

1540+letmacro = do

1541+ pos <- getPosition

1542+ controlSeq "let"

1543+ Tok _ (CtrlSeq name) _ <- anyControlSeq

1544+ optional $ symbol '='

1545+ contents <- braced <|> ((:[]) <$> anyControlSeq)

1546+ return (name, Macro ExpandWhenDefined 0 Nothing contents)

1547+

15351548newcommand :: PandocMonad m => LP m (Text, Macro)

15361549newcommand = do

15371550 pos <- getPosition

@@ -1546,13 +1559,15 @@ newcommand = do

15461559 spaces

15471560 optarg <- option Nothing $ Just <$> try bracketedToks

15481561 spaces

1549− contents <- braced

1562+ contents <- withVerbatimMode braced

1563+ -- we use withVerbatimMode, because macros are to be expanded

1564+ -- at point of use, not point of definition

15501565 when (mtype == "newcommand") $ do

15511566 macros <- sMacros <$> getState

15521567 case M.lookup name macros of

15531568 Just _ -> report $ MacroAlreadyDefined (T.unpack txt) pos

15541569 Nothing -> return ()

1555− return (name, Macro numargs optarg contents)

1570+ return (name, Macro ExpandWhenUsed numargs optarg contents)

15561571

15571572newenvironment :: PandocMonad m => LP m (Text, Macro, Macro)

15581573newenvironment = do

@@ -1568,16 +1583,16 @@ newenvironment = do

15681583 spaces

15691584 optarg <- option Nothing $ Just <$> try bracketedToks

15701585 spaces

1571− startcontents <- braced

1586+ startcontents <- withVerbatimMode braced

15721587 spaces

1573− endcontents <- braced

1588+ endcontents <- withVerbatimMode braced

15741589 when (mtype == "newenvironment") $ do

15751590 macros <- sMacros <$> getState

15761591 case M.lookup name macros of

15771592 Just _ -> report $ MacroAlreadyDefined (T.unpack name) pos

15781593 Nothing -> return ()

1579− return (name, Macro numargs optarg startcontents,

1580− Macro 0 Nothing endcontents)

1594+ return (name, Macro ExpandWhenUsed numargs optarg startcontents,

1595+ Macro ExpandWhenUsed 0 Nothing endcontents)

15811596

15821597bracketedToks :: PandocMonad m => LP m [Tok]

15831598bracketedToks = do

src/Text/Pandoc/Readers/LaTeX/Types.hs+5−1

@@ -30,6 +30,7 @@ Types for LaTeX tokens and macros.

3030module Text.Pandoc.Readers.LaTeX.Types ( Tok(..)

3131 , TokType(..)

3232 , Macro(..)

33+ , ExpansionPoint(..)

3334 , Line

3435 , Column )

3536where

4344data Tok = Tok (Line, Column) TokType Text

4445 deriving (Eq, Ord, Show)

4546

46−data Macro = Macro Int (Maybe [Tok]) [Tok]

47+data ExpansionPoint = ExpandWhenDefined | ExpandWhenUsed

48+ deriving (Eq, Ord, Show)

49+

50+data Macro = Macro ExpansionPoint Int (Maybe [Tok]) [Tok]

4751 deriving Show

4852

test/command/macros.md+23

@@ -15,3 +15,26 @@ $\my+\my$

1515\newcommand{\my}{\phi}

1616$\my+\my$

1717```

18+

19+`\let` macros should be expanded at point of

20+definition, while `\newcommand` macros should be

21+expanded at point of use:

22+

23+```

24+% pandoc -f latex -t latex

25+\let\a\b

26+\newcommand{\b}{\emph{ouk}}

27+\a

28+^D

29+\b

30+```

31+

32+```

33+% pandoc -f latex -t latex

34+\newcommand{\a}{\b}

35+\newcommand{\b}{\emph{ouk}}

36+\a

37+^D

38+\emph{ouk}

39+```

40+