{- |

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 (colonS, 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 -> (text channelS) <+> printChanDecs chans

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

proc_part = (text 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) <+> (text colonS) <+> (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 (ProcDecl pn args alpha) =

(pretty pn) <> (printArgs args) <+> (text colonS) <+> (pretty alpha)

where printArgs [] = empty

printArgs a = parens $ ppWithCommas a

printProcItem (ProcEq pn p) =

(pretty pn) <+> (text "=") <+> (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 pa =

(ppWithCommas (commSorts pa)) <+>

semi <+> (ppWithCommas (commChans pa))

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) <+> (pretty es)

Chaos es -> (text chaosS) <+> (pretty es)

NamedProcess pn es ->

(pretty pn) <+> lparen <+> (ppWithCommas es) <+> rparen

-- precedence 1

ConditionalProcess f p q ->

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

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

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

)

-- precedence 2

Hiding p es ->

(pretty p) <+> (text hidingS) <+> (pretty es)

RelationalRenaming p r ->

((pretty p) <+>

(text renaming_openS) <+>

(ppWithCommas r) <+>

(text renaming_closeS))

-- precedence 3

Sequential p q ->

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

PrefixProcess ev p ->

(pretty ev) <+> (text prefixS) <+> (glue pr p)

InternalPrefixProcess v s p ->

((text internal_prefixS) <+> (pretty v) <+>

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

(text prefixS) <+> (glue pr p)

)

ExternalPrefixProcess v s p ->

((text external_prefixS) <+> (pretty v) <+>

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

(text prefixS) <+> (glue pr p)

)

-- precedence 4

ExternalChoice p q ->

(pretty p) <+> (text external_choiceS) <+> (glue pr q)

InternalChoice p q ->

(pretty p) <+> (text internal_choiceS) <+> (glue pr q)

-- precedence 5

Interleaving p q ->

(pretty p) <+> (text interleavingS) <+> (glue pr q)

SynchronousParallel p q ->

(pretty p) <+> (text synchronousS) <+> (glue pr q)

GeneralisedParallel p es q ->

((pretty p) <+> (text general_parallel_openS) <+>

(pretty es) <+>

(text general_parallel_closeS) <+> (glue pr q))

AlphabetisedParallel p les res q ->

((pretty p) <+> (text alpha_parallel_openS) <+>

(pretty les) <+> (text alpha_parallel_sepS) <+> (pretty res) <+>

(text alpha_parallel_closeS) <+> (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 (Event t) = pretty t

printEvent (Send cn t) = (pretty cn) <+>

(text chan_sendS) <+>

(pretty t)

printEvent (Receive cn v s) = (pretty cn) <+>

(text chan_receiveS) <+>

(pretty v) <+>

(text colonS) <+>

(pretty s)

instance Pretty EVENT_SET where

pretty = printEventSet

printEventSet :: EVENT_SET -> Doc

printEventSet (EventSet s) = pretty s

printEventSet (ChannelEvents n) = (text chan_event_openS) <+>

(pretty n) <+>

(text chan_event_closeS)

printEventSet EmptyEventSet = text "{}"

instance Pretty CSP_FORMULA where

pretty = printCspFormula

printCspFormula :: CSP_FORMULA -> Doc

printCspFormula (Formula f) = pretty f