{- |

Module : $Id$

Description : Pretty printing for CspCASL

Copyright : (c) Andy Gimblett and Uni Bremen 2006

License : similar to LGPL, see HetCATS/LICENSE.txt or LIZENZ.txt

Maintainer : a.m.gimblett@swansea.ac.uk

Stability : provisional

Portability : portable

Printing abstract syntax of CSP-CASL

-}

module CspCASL.Print_CspCASL where

import CASL.ToDoc ()

import Common.Doc

import Common.DocUtils

import Common.Keywords (elseS, ifS, thenS)

import CspCASL.AS_CspCASL

import CspCASL.AS_CspCASL_Process

import CspCASL.CspCASL_Keywords

instance Pretty CspBasicSpec where

pretty = printCspBasicSpec

printCspBasicSpec :: CspBasicSpec -> Doc

printCspBasicSpec ccs =

chan_part $+$ proc_part

where chan_part = case (length chans) of

0 -> empty

1 -> (keyword channelS) <+> printChanDecs chans

_ -> (keyword channelsS) <+> printChanDecs chans

proc_part = (keyword processS) <+>

(printProcItems (proc_items ccs))

chans = channels ccs

printChanDecs :: [CHANNEL_DECL] -> Doc

printChanDecs cds = (vcat . punctuate semi . map pretty) cds

instance Pretty CHANNEL_DECL where

pretty = printChanDecl

printChanDecl :: CHANNEL_DECL -> Doc

printChanDecl (ChannelDecl ns s) =

(ppWithCommas ns) <+> colon <+> (pretty s)

printProcItems :: [PROC_ITEM] -> Doc

printProcItems ps = foldl ($+$) empty (map pretty ps)

instance Pretty PROC_ITEM where

pretty = printProcItem

printProcItem :: PROC_ITEM -> Doc

printProcItem (Proc_Decl pn args alpha) =

(pretty pn) <> (printArgs args) <+> colon <+> (pretty alpha) <+> semi

where printArgs [] = empty

printArgs a = parens $ ppWithCommas a

printProcItem (Proc_Eq pn p) =

(pretty pn) <+> equals <+> (pretty p)

instance Pretty PARM_PROCNAME where

pretty = printParmProcname

printParmProcname :: PARM_PROCNAME -> Doc

printParmProcname (ParmProcname pn args) =

pretty pn <> (printArgs args)

where printArgs [] = empty

printArgs a = parens $ ppWithCommas a

instance Pretty PROC_ALPHABET where

pretty = printProcAlphabet

printProcAlphabet :: PROC_ALPHABET -> Doc

printProcAlphabet (ProcAlphabet commTypes _) = ppWithCommas commTypes

instance Pretty PROCESS where

pretty = printProcess

printProcess :: PROCESS -> Doc

printProcess pr = case pr of

-- precedence 0

Skip _ -> text skipS

Stop _ -> text stopS

Div _ -> text divS

Run es _ -> (text runS) <+> lparen <+> (pretty es) <+> rparen

Chaos es _ -> (text chaosS) <+> lparen <+> (pretty es) <+> rparen

NamedProcess pn ts _ ->

(pretty pn) <+>

if (null ts)

then ppWithCommas ts

else lparen <+> (ppWithCommas ts) <+> rparen

-- precedence 1

ConditionalProcess f p q _ ->

((keyword ifS) <+> (pretty f) <+>

(keyword thenS) <+> (glue pr p) <+>

(keyword elseS) <+> (glue pr q)

)

-- precedence 2

Hiding p es _ ->

(pretty p) <+> hiding_proc <+> (pretty es)

RelationalRenaming p r _ ->

((pretty p) <+>

ren_proc_open <+> (ppWithCommas r) <+> ren_proc_close)

-- precedence 3

Sequential p q _ ->

(pretty p) <+> sequential <+> (glue pr q)

PrefixProcess ev p _ ->

(pretty ev) <+> prefix_proc <+> (glue pr p)

InternalPrefixProcess v s p _ ->

(internal_choice <+> (pretty v) <+>

(text svar_sortS) <+> (pretty s) <+>

prefix_proc <+> (glue pr p)

)

ExternalPrefixProcess v s p _ ->

(external_choice <+> (pretty v) <+>

(text svar_sortS) <+> (pretty s) <+>

prefix_proc <+> (glue pr p)

)

-- precedence 4

InternalChoice p q _ ->

(pretty p) <+> internal_choice <+> (glue pr q)

ExternalChoice p q _ ->

(pretty p) <+> external_choice <+> (glue pr q)

-- precedence 5

Interleaving p q _ ->

(pretty p) <+> interleave <+> (glue pr q)

SynchronousParallel p q _ ->

(pretty p) <+> synchronous <+> (glue pr q)

GeneralisedParallel p es q _ ->

((pretty p) <+> genpar_open <+> (pretty es) <+>

genpar_close <+> (glue pr q))

AlphabetisedParallel p les res q _ ->

((pretty p) <+> alpar_open <+>

(pretty les) <+> alpar_sep <+> (pretty res) <+>

alpar_close <+> (glue pr q)

)

-- glue and prec_comp decide whether the child in the parse tree needs

-- to be parenthesised or not. Parentheses are necessary if the

-- right-child is at the same level of precedence as the parent but is

-- a different operator; otherwise, they're not.

glue :: PROCESS -> PROCESS -> Doc

glue x y = if (prec_comp x y)

then lparen <+> pretty y <+> rparen

else pretty y

-- This is really nasty, but sledgehammer effective and allows fine

-- control. Unmaintainable, however. :-( I imagine there's a way to

-- compare the types in a less boilerplate manner, but OTOH there are

-- some special cases where it's nice to be explicit. Also, hiding

-- and renaming are distinctly non-standard. *shrug*

prec_comp :: PROCESS -> PROCESS -> Bool

prec_comp x y =

case x of

Hiding _ _ _ ->

case y of RelationalRenaming _ _ _ -> True

_ -> False

RelationalRenaming _ _ _ ->

case y of Hiding _ _ _ -> True

_ -> False

Sequential _ _ _ ->

case y of InternalPrefixProcess _ _ _ _ -> True

ExternalPrefixProcess _ _ _ _ -> True

_ -> False

PrefixProcess _ _ _ ->

case y of Sequential _ _ _ -> True

_ -> False

InternalPrefixProcess _ _ _ _ ->

case y of Sequential _ _ _ -> True

_ -> False

ExternalPrefixProcess _ _ _ _ ->

case y of Sequential _ _ _ -> True

_ -> False

ExternalChoice _ _ _ ->

case y of InternalChoice _ _ _ -> True

_ -> False

InternalChoice _ _ _ ->

case y of ExternalChoice _ _ _ -> True

_ -> False

Interleaving _ _ _ ->

case y of SynchronousParallel _ _ _ -> True

GeneralisedParallel _ _ _ _ -> True

AlphabetisedParallel _ _ _ _ _ -> True

_ -> False

SynchronousParallel _ _ _ ->

case y of Interleaving _ _ _ -> True

GeneralisedParallel _ _ _ _ -> True

AlphabetisedParallel _ _ _ _ _ -> True

_ -> False

GeneralisedParallel _ _ _ _ ->

case y of Interleaving _ _ _ -> True

SynchronousParallel _ _ _ -> True

AlphabetisedParallel _ _ _ _ _ -> True

_ -> False

AlphabetisedParallel _ _ _ _ _ ->

case y of Interleaving _ _ _ -> True

SynchronousParallel _ _ _ -> True

GeneralisedParallel _ _ _ _ -> True

_ -> False

_ -> False

instance Pretty EVENT where

pretty = printEvent

printEvent :: EVENT -> Doc

printEvent (TermEvent t _) = pretty t

printEvent (ChanSend cn t _) = (pretty cn) <+>

(text chan_sendS) <+>

(pretty t)

printEvent (ChanNonDetSend cn v s _) =

(pretty cn) <+> (text chan_sendS) <+>

(pretty v) <+> (text svar_sortS) <+> (pretty s)

printEvent (ChanRecv cn v s _) =

(pretty cn) <+> (text chan_receiveS) <+>

(pretty v) <+> (text svar_sortS) <+> (pretty s)

instance Pretty EVENT_SET where

pretty = printEventSet

printEventSet :: EVENT_SET -> Doc

printEventSet (EventSet es _) = ppWithCommas es

instance Pretty CSP_FORMULA where

pretty = printCspFormula

printCspFormula :: CSP_FORMULA -> Doc

printCspFormula (Formula f _) = pretty f