lib: Replace some regex functions with parsers.

hledger-lib/Hledger/Read/CsvReader.hs

@@ -41,6 +41,7 @@ where
 --- ** imports
 import Prelude ()
 import "base-compat-batteries" Prelude.Compat hiding (fail)
+import Control.Applicative        (liftA2)
 import Control.Exception          (IOException, handle, throw)
 import Control.Monad              (liftM, unless, when)
 import Control.Monad.Except       (ExceptT, throwError)
@@ -48,13 +49,13 @@ import qualified Control.Monad.Fail as Fail
 import Control.Monad.IO.Class     (MonadIO, liftIO)
 import Control.Monad.State.Strict (StateT, get, modify', evalStateT)
 import Control.Monad.Trans.Class  (lift)
-import Data.Char                  (toLower, isDigit, isSpace, isAlphaNum, ord)
+import Data.Char                  (toLower, isDigit, isSpace, isAlphaNum, isAscii, ord)
 import Data.Bifunctor             (first)
 import "base-compat-batteries" Data.List.Compat
 import qualified Data.List.Split as LS (splitOn)
-import Data.Maybe
+import Data.Maybe (catMaybes, fromMaybe, isJust)
 import Data.MemoUgly (memo)
-import Data.Ord
+import Data.Ord (comparing)
 import qualified Data.Set as S
 import Data.Text (Text)
 import qualified Data.Text as T
@@ -62,17 +63,17 @@ import qualified Data.Text.Encoding as T
 import qualified Data.Text.IO as T
 import Data.Time.Calendar (Day)
 import Data.Time.Format (parseTimeM, defaultTimeLocale)
-import Safe
+import Safe (atMay, headMay, lastMay, readDef, readMay)
 import System.Directory (doesFileExist)
-import System.FilePath
+import System.FilePath ((</>), takeDirectory, takeExtension, takeFileName)
 import qualified Data.Csv as Cassava
 import qualified Data.Csv.Parser.Megaparsec as CassavaMP
 import qualified Data.ByteString as B
 import qualified Data.ByteString.Lazy as BL
-import Data.Foldable
+import Data.Foldable (asum, toList)
 import Text.Megaparsec hiding (match, parse)
-import Text.Megaparsec.Char
-import Text.Megaparsec.Custom
+import Text.Megaparsec.Char (char, newline, string)
+import Text.Megaparsec.Custom (customErrorBundlePretty, parseErrorAt)
 import Text.Printf (printf)
 
 import Hledger.Data
@@ -834,10 +835,9 @@ validateCsv rules numhdrlines (Right rs) = validate $ applyConditionalSkips $ dr
         Nothing -> r:(applyConditionalSkips rest)
         Just cnt -> applyConditionalSkips (drop (cnt-1) rest)
     validate [] = Right []
-    validate rs@(_first:_)
-      | isJust lessthan2 = let r = fromJust lessthan2 in
-          Left $ printf "CSV record %s has less than two fields" (show r)
-      | otherwise        = Right rs
+    validate rs@(_first:_) = case lessthan2 of
+        Just r  -> Left $ printf "CSV record %s has less than two fields" (show r)
+        Nothing -> Right rs
       where
         lessthan2 = headMay $ filter ((<2).length) rs
 
@@ -1199,7 +1199,13 @@ getEffectiveAssignment rules record f = lastMay $ map snd $ assignments
 -- | Render a field assignment's template, possibly interpolating referenced
 -- CSV field values. Outer whitespace is removed from interpolated values.
 renderTemplate ::  CsvRules -> CsvRecord -> FieldTemplate -> String
-renderTemplate rules record t = replaceAllBy (toRegex' "%[A-z0-9_-]+") (replaceCsvFieldReference rules record) t  -- PARTIAL: should not happen
+renderTemplate rules record t = maybe t concat $ parseMaybe
+    (many $ takeWhile1P Nothing (/='%')
+        <|> replaceCsvFieldReference rules record <$> referencep)
+    t
+  where
+    referencep = liftA2 (:) (char '%') (takeWhile1P (Just "reference") isDescriptorChar) :: Parsec CustomErr String String
+    isDescriptorChar c = isAscii c && (isAlphaNum c || c == '_' || c == '-')
 
 -- | Replace something that looks like a reference to a csv field ("%date" or "%1)
 -- with that field's value. If it doesn't look like a field reference, or if we

hledger-lib/Hledger/Utils/String.hs

@@ -49,14 +49,14 @@ module Hledger.Utils.String (
  ) where
 
 
-import Data.Char
-import Data.List
-import Text.Megaparsec
-import Text.Megaparsec.Char
+import Data.Char (isDigit, isSpace, toLower, toUpper)
+import Data.List (intercalate, transpose)
+import Text.Megaparsec (Parsec, (<|>), (<?>), between, many, noneOf, oneOf,
+                        parseMaybe, sepBy, takeWhile1P)
+import Text.Megaparsec.Char (char, string)
 import Text.Printf (printf)
 
 import Hledger.Utils.Parse
-import Hledger.Utils.Regex
 
 
 -- | Take elements from the end of a list.
@@ -341,12 +341,15 @@ takeWidth w (c:cs) | cw <= w   = c:takeWidth (w-cw) cs
 -- (not counted), and line breaks (in a multi-line string, the longest
 -- line determines the width).
 strWidth :: String -> Int
-strWidth "" = 0
-strWidth s = maximum $ map (foldr (\a b -> charWidth a + b) 0) $ lines s'
-  where s' = stripAnsi s
+strWidth = maximum . (0:) . map (foldr (\a b -> charWidth a + b) 0) . lines . stripAnsi
 
 stripAnsi :: String -> String
-stripAnsi = regexReplace (toRegex' "\ESC\\[([0-9]+;)*([0-9]+)?[ABCDHJKfmsu]") "" -- PARTIAL: should never happen, no backreferences
+stripAnsi s = maybe s concat $ parseMaybe (many $ takeWhile1P Nothing (/='\ESC') <|> "" <$ ansi) s
+  where
+    -- This parses lots of invalid ANSI escape codes, but that should be fine
+    ansi = string "\ESC[" *> digitSemicolons *> suffix <?> "ansi" :: Parsec CustomErr String Char
+    digitSemicolons = takeWhile1P Nothing (\c -> isDigit c || c == ';')
+    suffix = oneOf ['A', 'B', 'C', 'D', 'H', 'J', 'K', 'f', 'm', 's', 'u']
 
 -- | Get the designated render width of a character: 0 for a combining
 -- character, 1 for a regular character, 2 for a wide character.