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| -rw-r--r-- | src/Trammel.hs | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/src/Trammel.hs b/src/Trammel.hs index 36c1140..bd3cd32 100644 --- a/src/Trammel.hs +++ b/src/Trammel.hs @@ -4,6 +4,7 @@ {-# LANGUAGE OverloadedLists #-} {-# LANGUAGE OverloadedStrings #-} {-# LANGUAGE RecordWildCards #-} +{-# LANGUAGE LambdaCase #-} module Trammel where import Control.Applicative @@ -214,3 +215,33 @@ pp t = renderString emptyRenderState t "" renderSGR :: Pm -> String renderSGR [] = [] renderSGR xs = ("\ESC["++) . (++"m") . intercalate ";" $ map show xs + + +trammelDrop :: Int -> Trammel String -> Trammel String +trammelDrop n = \case + Append t1 t2 -> + case compare n (len t1) of + LT -> Append (trammelDrop n t1) t2 + EQ -> t2 + GT -> trammelDrop (n - len t1) t2 + Plain s -> + Plain (drop n s) + SGR pm t -> + SGR pm (trammelDrop n t) + Empty -> + Empty + + +trammelTake :: Int -> Trammel String -> Trammel String +trammelTake n = \case + Append t1 t2 -> + case compare n (len t1) of + LT -> trammelTake n t1 + EQ -> t1 + GT -> Append t1 (trammelTake (n - len t1) t2) + Plain s -> + Plain (take n s) + SGR pm t -> + SGR pm (trammelTake n t) + Empty -> + Empty |