From 522c294ca813630240fd9dc8278d714a23105c45 Mon Sep 17 00:00:00 2001
From: mbays <mbays@sdf.org>
Date: Sat, 25 Dec 2021 00:00:00 +0000
Subject: [PATCH] add referring to end of list with $

---
 Command.hs     |  6 ++++--
 CommandLine.hs | 10 ++++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/Command.hs b/Command.hs
index 034f0b9..3ef4a4c 100644
--- a/Command.hs
+++ b/Command.hs
@@ -189,8 +189,10 @@ helpOn s =
             , "  Specify first match of pattern with \"^pattern^\","
             , "  or all matches with \"^^pattern^\"."
             , "  Specify multiple items or ranges by separating with \",\"."
-            , "  Examples: \"1,3-5,^pattern^-\" refers to links 1,3,4,5 and all links from the"
-            , "    the first match of pattern onwards, and \"~-\" refers to the whole queue."
+            , "  Last item is denoted by \"$\", and nth from last by \"$n\"."
+            , "  Examples: \"1,3-5,^pattern^-$2\" refers to links 1,3,4,5 and all links from"
+            , "    the first match of pattern to the penultimate item;"
+            , "    \"~-\" refers to the whole queue."
             , ""
             , "  Patterns are (extended) regular expressions (see `man 7 regex`)."
             , "  Matching is case-insensitive unless pattern contains an uppercase character."
diff --git a/CommandLine.hs b/CommandLine.hs
index a4d639c..e60f3e3 100644
--- a/CommandLine.hs
+++ b/CommandLine.hs
@@ -32,6 +32,7 @@ import           Text.Parsec.String (Parser)
 
 data ElemSpec
     = ESNum Int
+    | ESNumFromEnd Int
     | ESSearch String
     deriving (Eq,Ord,Show)
 
@@ -64,6 +65,7 @@ resolveElemsSpecs typeStr match as ess =
 
     resolveES :: ElemSpec -> Either String Int
     resolveES (ESNum n) = return $ n - 1
+    resolveES (ESNumFromEnd n) = return $ length as - n
     resolveES (ESSearch s) =
         maybe (Left $ "No " <> typeStr <> " matches pattern: " ++ s) Right $
             headMay . map fst . filter snd . zip [0..] $ (s `match`) <$> as
@@ -142,6 +144,10 @@ patt = escapedWhile (noneOf "^ ") <* optional (char '^')
 elemSpec :: Parser ElemSpec
 elemSpec = choice
     [ ESNum <$> nat
+    , char '$' >> ESNumFromEnd <$> choice
+        [ nat
+        , (+ 1) <$> countMany (string "$")
+        ]
     , char '^' >> ESSearch <$> patt ]
 
 elemsSpec :: Parser ElemsSpec
@@ -170,9 +176,9 @@ ref = escapedArgStartingWith . oneOf
 
 baseTarget :: Parser PTarget
 baseTarget = choice
-    [ PTargetLinks False PTargetCurr <$> elemsSpecs
+    [ PTargetLog <$> elemsSpecsBy (string "$")
+    , PTargetLinks False PTargetCurr <$> elemsSpecs
     , PTargetRef PTargetCurr <$> ref "./?"
-    , PTargetLog <$> elemsSpecsBy (string "$")
     , PTargetQueue <$> elemsSpecsBy (string "~")
     , char '\'' >> choice
         [ char '\'' >> return PTargetJumpBack
-- 
2.11.4.GIT