Clarify CLI options

README.md

@@ -64,27 +64,25 @@ tricu [COMMAND] ... [OPTIONS]
   tricu: Exploring Tree Calculus
 
 Common flags:
-  -? --help           Display help message
-  -V --version        Print version information
+  -? --help       Display help message
+  -V --version    Print version information
 
 tricu [repl] [OPTIONS]
   Start interactive REPL
 
 tricu eval [OPTIONS]
-  Evaluate a file and return the result of the expression in the final line
+  Evaluate tricu and return the result of the final expression.
 
-  -f --file=FILE      Optional input file path for evaluation.
-                        Defaults to stdin.
-  -o --output=OUTPUT  Optional output file path for resulting output.
-                        Defaults to stdout.
-  -t --form=FORM      Optional output form: (fsl|tree|ast|ternary|ascii).
-                        Defaults to fsl.
+  -f --file=FILE  Input file path(s) for evaluation.
+                    Defaults to stdin.
+  -t --form=FORM  Optional output form: (fsl|tree|ast|ternary|ascii).
+                    Defaults to fsl "Fork Stem Leaf" form.
 
 tricu decode [OPTIONS]
-  Decode a Tree Calculus value into a string representation
+  Decode a Tree Calculus value into a string representation.
 
-  -f --file=FILE      Optional input file path to attempt decoding.
-                        Defaults to stdin.
+  -f --file=FILE  Optional input file path to attempt decoding.
+                    Defaults to stdin.
 ```
 
 ## Acknowledgements 

src/Main.hs

@@ -29,7 +29,7 @@ evaluateMode :: TricuArgs
 evaluateMode = Evaluate
   { file = def &= help "Input file path(s) for evaluation.\n \
       \ Defaults to stdin."
-      &= name "f"
+      &= name "f" &= typ "FILE"
     , form = FSL &= typ "FORM"
       &= help "Optional output form: (fsl|tree|ast|ternary|ascii).\n \
       \ Defaults to fsl \"Fork Stem Leaf\" form."
@@ -42,9 +42,9 @@ evaluateMode = Evaluate
 decodeMode :: TricuArgs
 decodeMode = Decode
   { file = def
-    &= help "Optional input file path(s) to attempt decoding.\n \
+    &= help "Optional input file path to attempt decoding.\n \
     \ Defaults to stdin."
-    &= name "f"
+    &= name "f" &= typ "FILE"
   }
   &= help "Decode a Tree Calculus value into a string representation."
   &= explicit