Files
gf-core/src/compiler/GF/Command/Abstract.hs
hallgren ab3cc77656 GF shell: fix a parsing problem with the cc command
This patch fixes a problem introduced last year when the GF shell was
refactored to allow more commands to be treated uniformly and be part
of pipes. The cc command was one of those commands, but unfortunately this
introduced a parsing problem, e.g.

	> cc "last"
	constant not found: last

	> cc "last"++"year"
	command not parsed: cc "last"++"year"

This happened because the generic command line parser in
GF.Command.{Abstract,Parse} assumes that all commands have an argument of
type PGF.Expr. Commands that expect other types of arguments have to
use PGF.showExpr combined with other conversion to the argument type they
expect. The cc command excpets a GF.Grammar.Term, and unfortunately not 
all terms survice the roundtrip through PGF.Expr, in part because of
an additional hack to allow strings to be roundtripped through PGF.Expr
without adding superfluous double quotes.

To solve the problem, this patch

 + makes room for arguments of type Term in the Argument type in
   GF.Command.Abstract.
   
 + makes a special case for the cc command in GF.Command.Parse, by
   calling the partial parser 'runPartial pTerm' recently added in
   GF.Grammar.Lexer and GF.Grammar.Parser. Care was taken so that
   that "|" and ";" can be used both inside terms and as separators between
   commands in the shell, e.g. things like the following now work:

       > cc ("a"|"b") | ps -lexcode
       variants { "a" ; "b" }

 + introduces a type CommandArgument that replaces [Expr] as the
   type of values passed between commands in pipes. It has room for
   values of type [Expr], [String] and Term, thus eliminating the need
   to roundtrip through the Expr type all the time.
   The hack to avoid adding superfluous quotes when strings are
   roundtripped through Expr has been left in place for now,
   but can probably be removed.
2016-04-07 13:40:05 +00:00

87 lines
1.8 KiB
Haskell

module GF.Command.Abstract(module GF.Command.Abstract,Expr,showExpr,Term) where
import PGF(CId,mkCId,Expr,showExpr)
import GF.Grammar.Grammar(Term)
type Ident = String
type CommandLine = [Pipe]
type Pipe = [Command]
data Command
= Command Ident [Option] Argument
deriving (Eq,Ord,Show)
data Option
= OOpt Ident
| OFlag Ident Value
deriving (Eq,Ord,Show)
data Value
= VId Ident
| VInt Int
| VStr String
deriving (Eq,Ord,Show)
data Argument
= AExpr Expr
| ATerm Term
| ANoArg
| AMacro Ident
deriving (Eq,Ord,Show)
valCIdOpts :: String -> CId -> [Option] -> CId
valCIdOpts flag def opts =
case [v | OFlag f (VId v) <- opts, f == flag] of
(v:_) -> mkCId v
_ -> def
valIntOpts :: String -> Int -> [Option] -> Int
valIntOpts flag def opts =
case [v | OFlag f (VInt v) <- opts, f == flag] of
(v:_) -> v
_ -> def
valStrOpts :: String -> String -> [Option] -> String
valStrOpts flag def opts =
case listFlags flag opts of
v:_ -> valueString v
_ -> def
listFlags flag opts = [v | OFlag f v <- opts, f == flag]
valueString v =
case v of
VStr v -> v
VId v -> v
VInt v -> show v
isOpt :: String -> [Option] -> Bool
isOpt o opts = elem (OOpt o) opts
isFlag :: String -> [Option] -> Bool
isFlag o opts = elem o [x | OFlag x _ <- opts]
optsAndFlags :: [Option] -> ([Option],[Option])
optsAndFlags = foldr add ([],[]) where
add o (os,fs) = case o of
OOpt _ -> (o:os,fs)
OFlag _ _ -> (os,o:fs)
prOpt :: Option -> String
prOpt o = case o of
OOpt i -> i
OFlag f x -> f ++ "=" ++ show x
mkOpt :: String -> Option
mkOpt = OOpt
-- abbreviation convention from gf commands
getCommandOp s = case break (=='_') s of
(a:_,_:b:_) -> [a,b] -- axx_byy --> ab
_ -> case s of
[a,b] -> s -- ab --> ab
a:_ -> [a] -- axx --> a