{- |

Module : $Header$

Description : A parser for first-order logic with dependent types (DFOL)

Copyright : (c) Kristina Sojakova, DFKI Bremen 2009

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

Maintainer : k.sojakova@jacobs-university.de

Stability : experimental

Portability : portable

-}

module DFOL.Parse_AS_DFOL

(

basicSpec -- parser for DFOL specifications

, symbItems -- parser for symbol lists

, symbMapItems -- parser for symbol map lists

)

where

import qualified Common.Lexer as Lexer

import Common.Parsec

import Common.Token (casl_structured_reserved_words)

import qualified Common.Keywords as Keywords

import qualified Common.AnnoState as AnnoState

import DFOL.AS_DFOL

import Text.ParserCombinators.Parsec

-- keywords which cannot appear as identifiers in a signature

dfolKeys :: [String]

dfolKeys = [Keywords.trueS,

Keywords.falseS,

Keywords.notS,

Keywords.forallS,

Keywords.existsS,

"Univ",

"Sort",

"Form",

"Pi"] ++ casl_structured_reserved_words

-- parser for basic spec

basicSpec :: AnnoState.AParser st BASIC_SPEC

basicSpec = fmap Basic_spec (AnnoState.trailingAnnosParser basicItemP)

<|>

(Lexer.oBraceT >> Lexer.cBraceT >> return (Basic_spec []))

-- parser for basic items

basicItemP :: AnnoState.AParser st BASIC_ITEM

basicItemP = do AnnoState.dotT

f <- formulaP

return $ Axiom_item f

<|>

do ns <- namesP

AnnoState.asKey "::"

t <- typeP

return $ Decl_item (ns, t)

-- parser for all types

typeP :: AnnoState.AParser st TYPE

typeP = do AnnoState.asKey "Pi"

vs <- varsP

t <- typeP

return $ Pi vs t

<|>

do t <- type1P

(do AnnoState.asKey Keywords.funS

(ts, _) <- type1P `Lexer.separatedBy`

AnnoState.asKey Keywords.funS

let xs = t:ts

return $ Func (init xs) (last xs)

<|>

return t)

-- parser for basic types and types enclosed in parentheses

type1P :: AnnoState.AParser st TYPE

type1P = do AnnoState.asKey "Sort"

return Sort

<|>

do AnnoState.asKey "Form"

return Form

<|>

do AnnoState.asKey "Univ"

Lexer.oParenT

t <- termP

Lexer.cParenT

return $ Univ t

<|>

do t <- termP

return $ Univ t

<|>

do Lexer.oParenT

t <- typeP

Lexer.cParenT

return t

-- parser for terms

termP :: AnnoState.AParser st TERM

termP = do f <- nameP

do Lexer.oParenT

(as, _) <- termP `Lexer.separatedBy` AnnoState.anComma

Lexer.cParenT

return $ Appl (Identifier f) as

<|> return (Identifier f)

-- parsers for names

nameP :: AnnoState.AParser st NAME

nameP = Lexer.pToken $ reserved dfolKeys Lexer.scanAnyWords

namesP :: AnnoState.AParser st [NAME]

namesP = fmap fst $ nameP `Lexer.separatedBy` AnnoState.anComma

-- parser for variable declarations

varP :: AnnoState.AParser st ([NAME], TYPE)

varP = do ns <- namesP

AnnoState.asKey Keywords.colonS

t <- typeP

return (ns, t)

varsP :: AnnoState.AParser st [([NAME], TYPE)]

varsP = do (vs, _) <- varP `Lexer.separatedBy` AnnoState.asKey ";"

AnnoState.dotT

return vs

-- parser for all formulas

formulaP :: AnnoState.AParser st FORMULA

formulaP = forallP

<|>

existsP

<|>

formula1P

{- parser for equivalences, implications, conjunctions, disjunctions,

negations, equalities, atomic formulas, and formulas in parentheses -}

formula1P :: AnnoState.AParser st FORMULA

formula1P = do f <- formula2P

(-- equivalences

do AnnoState.asKey Keywords.equivS

g <- formula2P

return $ Equivalence f g

<|>

-- implications

do AnnoState.asKey Keywords.implS

g <- formula2P

return $ Implication f g

<|>

-- all other cases

return f)

{- parser for conjunctions, disjunctions, negations, equalities,

atomic formulas, and formulas in parentheses -}

formula2P :: AnnoState.AParser st FORMULA

formula2P = do f <- formula3P

(-- conjunctions

do AnnoState.asKey Keywords.lAnd

(fs, _) <- formula3P `Lexer.separatedBy`

AnnoState.asKey Keywords.lAnd

return $ Conjunction (f:fs)

<|>

-- disjunctions

do AnnoState.asKey Keywords.lOr

(fs, _) <- formula3P `Lexer.separatedBy`

AnnoState.asKey Keywords.lOr

return $ Disjunction (f:fs)

<|>

-- all other cases

return f)

{- parser for negations, equalities, atomic formulas,

and formulas in parentheses -}

formula3P :: AnnoState.AParser st FORMULA

formula3P = parenFormulaP

<|>

negP

<|>

formula4P

<|>

trueP

<|>

falseP

-- parser for equalities and predicate formulas

formula4P :: AnnoState.AParser st FORMULA

formula4P = do x <- termP

(-- equalities

do AnnoState.asKey "=="

y <- termP

return $ Equality x y

<|>

-- predicates

return (Pred x))

-- parser for formulas enclosed in parentheses

parenFormulaP :: AnnoState.AParser st FORMULA

parenFormulaP = do Lexer.oParenT

f <- formulaP

Lexer.cParenT

return f

-- parser for forall formulas

forallP :: AnnoState.AParser st FORMULA

forallP = do AnnoState.asKey Keywords.forallS

vs <- varsP

f <- formulaP

return $ Forall vs f

-- parser for exists formulas

existsP :: AnnoState.AParser st FORMULA

existsP = do AnnoState.asKey Keywords.existsS

vs <- varsP

f <- formulaP

return $ Exists vs f

-- parser for negations

negP :: AnnoState.AParser st FORMULA

negP = do AnnoState.asKey Keywords.negS <|> AnnoState.asKey Keywords.notS

f <- formula3P

return $ Negation f

-- parser for true

trueP :: AnnoState.AParser st FORMULA

trueP = do AnnoState.asKey Keywords.trueS

return T

-- parser for false

falseP :: AnnoState.AParser st FORMULA

falseP = do AnnoState.asKey Keywords.falseS

return F

-- parser for symbol items

symbItems :: AnnoState.AParser st SYMB_ITEMS

symbItems = fmap Symb_items namesP

-- parser for symbol map items

symbMapItems :: AnnoState.AParser st SYMB_MAP_ITEMS

symbMapItems = do (xs, _) <- symbOrMap `Lexer.separatedBy` AnnoState.anComma

return $ Symb_map_items xs

-- parser for symbols or symbol maps

symbOrMap :: AnnoState.AParser st SYMB_OR_MAP

symbOrMap = do s <- nameP

(do AnnoState.asKey Keywords.mapsTo

t <- nameP

return $ Symb_map s t

<|>

return (Symb s))