Merge pull request #8 from Kerl13/master

Usual functions' names & simple fractions

.gitignore

@@ -1 +1,6 @@
 *.pandoc.pdf
+dist/
+filters/*.hi
+filters/*.o
+filters/usual-fun
+filters/nice-frac

LICENSE

@@ -0,0 +1,3 @@
+As long as you retain this notice you can do whatever you want with this stuff.
+If we meet some day, and you think this stuff is worth it, you can buy me a beer
+in return.

Makefile

@@ -1,11 +1,29 @@
 SOURCES = $(wildcard *.md)
 OUT = $(SOURCES:.md=.pdf)
 
-all: $(OUT)
+HS_FILTERS_NAMES = nice-frac usual-fun
+PY_FILTERS_NAMES = pandoc-svg.py
+EXT_FILTERS = pandoc-crossref
 
-$(OUT): $(SOURCES)
-	pandoc --smart -t latex $< --filter=filters/pandoc-svg.py --filter=pandoc-crossref -o $@
+HS_FILTERS = $(addprefix filters/, $(HS_FILTERS_NAMES))
+PY_FILTERS = $(addprefix filters/, $(PY_FILTERS_NAMES))
+FILTERS = $(PY_FILTERS) $(HS_FILTERS) $(EXT_FILTERS)
+
+.SUFFIXES: .hs
+
+all: $(HS_FILTERS) $(OUT)
+
+$(OUT):
+	pandoc -S -t latex $(basename $@).md $(addprefix --filter=, $(FILTERS)) -o $@
+
+$(HS_FILTERS):
+	ghc --make $@.hs -o $@	
 
 clean:
 	rm -f $(OUT)
+	rm -f $(addprefix filters/, $(HS_FILTERS))
 	find . -name "*.pandoc.pdf" -delete
+
+deepclean: clean
+	rm -f $(HS_FILTERS)
+	rm -f filters/*.hi filters/*.o

README.md

@@ -7,21 +7,19 @@ Pandoc.
 Includes various Pandoc filters:
 
 * Automatically convert `SVG` files to `PDF` and rewrite the image link to
-  include them in the document easily.
+include them in the document easily.
 
 * Include [pandoc-crossref](https://github.com/lierdakil/pandoc-crossref) for
-  easy numbering and referencing.
+easy numbering and referencing.
 
+* Convert simple fractions like "(n / k)" to LaTeX's "\\frac{n}{k}" when n and
+k are integers in a math environment.
+
+* automatically convert function names (cos, sin, exp, log) to their
+LaTeX equivalent (\\cos and so on) when in a mathematical environment,
+then taking out the useless leading `\`.
 
 ## TODO
 
-* automatically convertfunction names (cos, sin, exp, log) to their
-LaTeX equivalent (\cos and so on) when in a mathematical environment,
-then taking out the useless leading `\`.
-
-* not having to use \frac{}{} to write fractions, but instead
-automatically convert simple fractions in math environment to \frac{}{}
-(for instance convert "(1 / 2)" to "\frac{1}{2}")
-
 * anything else like this that could help writing more readable LaTeX
 code :)

filters/nice-frac.hs

@@ -0,0 +1,26 @@
+-- nice-frac.hs
+
+import Text.Pandoc.JSON
+import Text.Regex
+
+-- Usefull regex elements
+space :: String
+space = "[ \\t\\n\\r]*"
+num :: String
+num = "([0-9]+)"
+
+-- Replace fractions like "(42 / 1)" by "\frac{42}{1}" 
+fracReg :: Regex
+fracReg = mkRegex $
+  "\\(" ++ space ++ num ++ space ++ "/" ++ space ++ num ++ space ++ "\\)"
+frac :: String -> String
+frac s = subRegex fracReg s "\\\\frac{\\1}{\\2}"
+
+-- Apply the substitution to all Latex parts on the AST
+niceFrac :: Inline -> Inline
+niceFrac (Math t s) = Math t (frac s)
+niceFrac x = x
+
+main :: IO ()
+main = toJSONFilter niceFrac
+

filters/usual-fun.hs

@@ -0,0 +1,33 @@
+-- usual-fun.hs
+
+import Text.Pandoc.JSON
+import Text.Regex
+import Data.List (intercalate)
+
+-- Association list for usual functions
+usual :: String
+usual = intercalate "|" [
+  "cos", "sin", "tan", "cotan",
+  "arccos", "arcsin", "arctan",
+  "exp", "log"]  
+
+-- Remove the '\' before usual functions' names if present
+rmBSReg :: Regex
+rmBSReg = mkRegex $ "(\\\\)(" ++ usual ++ ")\\>"
+rmBS :: String -> String
+rmBS s = subRegex rmBSReg s "\\2"
+
+-- Add a '\' before usual functions' names
+addBSReg :: Regex
+addBSReg = mkRegex $ "\\<(" ++ usual ++ ")\\>"
+addBS :: String -> String
+addBS s = subRegex addBSReg s "\\\\\\0"
+
+-- Apply the substitution to all Latex parts on the AST
+niceFrac :: Inline -> Inline
+niceFrac (Math t s) = Math t (addBS . rmBS $ s)
+niceFrac x = x
+
+main :: IO ()
+main = toJSONFilter niceFrac
+

pandoc-boilerplate.cabal

@@ -0,0 +1,25 @@
+-- Initial pandoc-boilerplate.cabal generated by cabal init.  For further 
+-- documentation, see http://haskell.org/cabal/users-guide/
+
+name:                pandoc-boilerplate
+version:             0.1.0.0
+-- synopsis:
+-- description:         
+homepage:            https://github.com/Phyks/pandoc_boilerplate
+license:             Beerware
+license-file:        LICENSE
+author:              Martin Pépin
+maintainer:          martin.pepin@netcourrier.com
+-- copyright:           
+-- category:            
+build-type:          Simple
+extra-source-files: 
+cabal-version:       >=1.10
+
+library
+  -- exposed-modules:     
+  -- other-modules:       
+  -- other-extensions:    
+  build-depends:       pandoc, regex-compat, base >=4.6 && <4.7
+  -- hs-source-dirs:      
+  default-language:    Haskell2010