imp: demo: output cleanups

hledger/Hledger/Cli/Commands/Demo.hs

@@ -13,8 +13,7 @@ module Hledger.Cli.Commands.Demo (
 
 import Hledger
 import Hledger.Cli.CliOptions
-import Control.Monad (forM_)
-import System.Exit (exitSuccess, exitFailure)
+import System.Exit (exitFailure)
 import Text.Printf
 import Control.Concurrent (threadDelay)
 import System.Process (callProcess)
@@ -47,7 +46,10 @@ demomode = hledgerCommandMode
   []
   [generalflagsgroup3]
   []
-  ([], Just $ argsFlag "[NUM|NAME|STR] [-- ASCIINEMAOPTS]")
+  ([], Just $ argsFlag optsstr)
+
+optsstr = "[NUM|PREFIX|SUBSTR] [-- ASCIINEMAOPTS]"
+usagestr = "Usage: hledger demo " <> optsstr
 
 -- | The demo command.
 demo :: CliOpts -> Journal -> IO ()
@@ -55,15 +57,13 @@ demo CliOpts{rawopts_=rawopts, reportspec_=ReportSpec{_rsQuery=_query}} _j = do
   -- demos <- getCurrentDirectory >>= readDemos
   let args = listofstringopt "args" rawopts
   case args of
-    [] -> do
-      forM_ (zip [(1::Int)..] demos) $ \(i, Demo t _) -> printf "%d) %s\n" i t
-      exitSuccess
-
+    [] -> putStrLn usagestr >> printDemos
     (a:as) ->
       case findDemo demos a of
         Nothing -> do
-          putStrLn $ a <> " not recognized"
-          putStrLn "Usage: hledger-demo [NUM|NAME|STR], run with no arguments to see a list"
+          putStrLn $ "No demo \"" <> a <> "\" was found."
+          putStrLn usagestr
+          printDemos
           exitFailure
 
         Just (Demo t c) -> do
@@ -90,6 +90,12 @@ findDemo ds s =
   where
     sl = lowercase s
 
+printDemos :: IO ()
+printDemos = putStrLn $ unlines $
+  "Demos:" :
+  "" :
+  [show i <> ") " <> t | (i, Demo t _) <- zip [(1::Int)..] demos]
+
 -- | Run asciinema play, passing content to its stdin.
 runAsciinemaPlay :: ByteString -> [String] -> IO ()
 runAsciinemaPlay content args =

hledger/Hledger/Cli/Commands/Demo.md

@@ -5,7 +5,7 @@ Play small demos of hledger usage in the terminal.
 _FLAGS
 
 Run this command with no argument to list the demos.
-To play a demo, write its number or name or a substring.
+To play a demo, write its number or a prefix or substring of its title.
 asciinema must be installed.
 
 During playback, several keys are available:
@@ -13,14 +13,14 @@ During playback, several keys are available:
 - .       step forward (while paused)
 - CTRL-c  quit early
 
-asciinema options can be added following a double-dash;
-list them with `asciinema -h`. `-s` (speed) and 
-`-i` (max idle time) are particularly useful.
+asciinema options can be added following a double dash, such as
+`-s` (adjust speed) and `-i` (limit idle time).
+Run `asciinema -h` to list these.
 
 Examples:
 ```shell
 $ hledger demo                   # list available demos
 $ hledger demo 1                 # play the first demo
-$ hledger demo install -s5 -i.5  # play the demo named or containing "install",
-                                 # at 5x speed, limiting idle time to 0.5s.
+$ hledger demo install -s5 -i.5  # play the install demo at 5x speed,
+                                 # with pauses limited to half a second.
 ```

hledger/Hledger/Cli/Commands/Demo.txt

@@ -5,13 +5,14 @@ Play small demos of hledger usage in the terminal.
 _FLAGS
 
 Run this command with no argument to list the demos. To play a demo,
-write its number or name or a substring. asciinema must be installed.
+write its number or a prefix or substring of its title. asciinema must
+be installed.
 
 During playback, several keys are available: - SPACE pause/unpause - .
 step forward (while paused) - CTRL-c quit early
 
-asciinema options can be added following a double-dash; list them with
-asciinema -h. -s (speed) and -i (max idle time) are particularly useful.
+asciinema options can be added following a double dash, such as -s
+(adjust speed) and -i (limit idle time). Run asciinema -h to list them.
 
 Examples: