[Basic VersionTool
Manuel M T Chakravarty <chak@cse.unsw.edu.au>**20060531165550] {
move ./Config.hs ./Config.hs.in
addfile ./VersionTool.hs
hunk ./Config.hs.in 51
-versnum    = "0.3.0"
-versnick   = "'Lambdas are food for thought'"
-date	   = "29 May 2006"
+versnum    = "@VERSION@"
+versnick   = "@VERSNICK@"
+date	   = "@VERSDATE@"
hunk ./README 7
-into HTML for inclusion into web pages.
+into HTML for inclusion into web pages.  The project web site is at
+
+  http://www.cse.unsw.edu.au/~chak/lambdaFeed/
hunk ./VersionTool.hs 1
+#!/bin/env runhaskell  
+
+-- |Tool to insert version information into program source
+--
+--  Copyright (c) 2006 Manuel M T Chakravarty
+--
+--  License: BSD3 <url?>
+--
+--- Description ---------------------------------------------------------------
+--
+--  Extract version information from a .cabal file and from darcs, and then,
+--  insert it into a source file.  The name of the source file that is to be
+--  rewritten with the version information must be passed as the only argument
+--  to VersionTool.  If that file's name is `Config.hs', there must be a
+--  template file `Config.hs.in' containing version information markers where
+--  VersionTool is supposed to enter the version information.  The markers are
+--  the following:
+--
+--    VERSION	-- version number, typically in XX.YY.ZZ format
+--    VERSNICK  -- version nickname, a string that may contain white space
+--    VERSDATE  -- date of version in DD MMM YYYY format (MMM is alpha)
+--    
+
+module Main (main)
+where
+
+import Data.Char (
+  toLower, isSpace)
+import Control.Monad (
+  when, unless, liftM)
+import System.Directory (
+  getDirectoryContents, doesFileExist)
+import System.Environment (
+  getArgs)
+import System.Time (
+  ClockTime, Month, CalendarTime(..), getClockTime, toUTCTime)
+
+
+-- Constants
+--
+inSuffix :: String
+inSuffix = ".in"
+
+-- Actual program
+--
+main :: IO ()
+main =
+  do
+    -- Get name of source file into which we enter the version information
+    args <- getArgs
+    when (length args /= 1) $
+      error "Usage: VersionTool.hs CONFIG-FILE"
+    let configFName = head args
+    exists <- doesFileExist (configFName ++ ".in")
+    unless exists $
+      error $ "VersionTool: `" ++ configFName ++ ".in' does not exist"
+
+    -- Get the package's Cabal file and extract version information from it
+    fnames <- getDirectoryContents "."
+    let cabalFNames = [fname | fname <- fnames, suffix fname == "cabal"]
+    when (null cabalFNames) $
+      error "VersionTool: no .cabal file in current directory"
+    (version, versnick) <- getCabalInfo (head cabalFNames)
+
+    -- Get current date
+    versdate <- getCurrentDate
+
+    -- Enter the gathered information into the configuration file
+    rewriteFile configFName version versnick versdate
+
+
+-- Cabal file processing
+-- ---------------------
+
+-- Extract version information (version number and version nick) from Cabal
+-- file.
+--
+getCabalInfo :: FilePath -> IO (String, String)
+getCabalInfo fname =
+  do
+    cabalSpec <- liftM lines $ readFile fname
+    let versionLs  = [line | line <- cabalSpec, "Version" `isPrefix` line]
+	versnickLs = [line | line <- cabalSpec, "--Versnick" `isPrefix` line]
+    when (null versionLs) $
+      error $ "VersionTool: no line with `version' tag in `" ++ fname ++ "'"
+    when (null versnickLs) $
+      putStrLn $ "Warning: VersionTool: no line with `--versnick' tag in `" ++
+	         fname ++ "'"
+    return (extract versionLs, extract versnickLs)
+  where
+    extract ls | null ls   = ""
+	       | otherwise = clean . tail . dropWhile (/= ':') . head $ ls
+
+
+-- Date information
+-- ----------------
+
+-- Get the current date in `DD MMM YYYY' format.
+--
+getCurrentDate :: IO String
+getCurrentDate =
+  do
+    time <- liftM toUTCTime $ getClockTime
+    let preday = show $ ctDay time
+        day    = if length preday == 1 then ' ':preday else preday
+	month  = take 3 (show $ ctMonth time)
+	year   = show $ ctYear time
+    return $ day ++ " " ++ month ++ " " ++ year
+
+
+-- Target rewriting
+-- ----------------
+
+-- Enter version information into the configuration source.
+--
+rewriteFile :: FilePath -> String -> String -> String -> IO ()
+rewriteFile fname version versnick versdate =
+  do
+    contents <- readFile (fname ++ inSuffix)
+    writeFile fname (rewrite contents)
+  where
+    rewrite ""         = ""
+    rewrite ('@':rest) = case match rest of
+			   Nothing           -> '@' : rewrite rest
+			   Just (new, rest') -> new ++ rewrite rest'
+    rewrite (c  :rest) = c : rewrite rest
+    --
+    match str | "VERSION@"  `isPrefix` str = 
+	        Just (version,  drop (length "VERSION@" ) str)
+	      | "VERSNICK@" `isPrefix` str = 
+		Just (versnick, drop (length "VERSNICK@") str)
+	      | "VERSDATE@" `isPrefix` str = 
+	        Just (versdate, drop (length "VERSDATE@") str)
+    match _                                = Nothing
+
+
+-- Utility functions
+-- -----------------
+
+-- Lose leading and trailing whitespace.
+--
+clean :: String -> String
+clean = reverse . dropWhile isSpace . reverse . dropWhile isSpace
+
+-- Check for string prefix disregarding case.
+--
+isPrefix :: String -> String -> Bool
+str1 `isPrefix` str2 = 
+  map toLower str1 == map toLower (take (length str1) str2)
+
+-- Project the suffix from a filename.
+--
+suffix :: FilePath -> String
+suffix = reverse . takeWhile (/= '.') . reverse
hunk ./lambdaFeed.cabal 3
---Versnick:	"Lambdas are food for thought"
---Versdate:	"29 May 2006"
+--Versnick:	'Lambdas are food for thought'
}