churf/Grammar.cf
2023-03-22 12:45:51 +01:00

91 lines
2.8 KiB
CFEngine3

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-- * PROGRAM
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Program. Program ::= [Def] ;
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-- * TOP-LEVEL
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DBind. Def ::= Bind ;
DSig. Def ::= Sig ;
DData. Def ::= Data ;
Sig. Sig ::= LIdent ":" Type ;
Bind. Bind ::= LIdent [LIdent] "=" Exp ;
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-- * TYPES
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TLit. Type2 ::= UIdent ;
TVar. Type2 ::= TVar ;
TAll. Type1 ::= "forall" TVar "." Type ;
TIndexed. Type1 ::= Indexed ;
internal TEVar. Type1 ::= TEVar ;
TFun. Type ::= Type1 "->" Type ;
MkTVar. TVar ::= LIdent ;
internal MkTEVar. TEVar ::= LIdent ;
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-- * DATA TYPES
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Constructor. Constructor ::= UIdent ":" Type ;
Indexed. Indexed ::= UIdent "(" [Type] ")" ;
Data. Data ::= "data" Indexed "where" "{" [Constructor] "}" ;
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-- * EXPRESSIONS
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EAnn. Exp5 ::= "(" Exp ":" Type ")" ;
EId. Exp4 ::= LIdent ;
ELit. Exp4 ::= Lit ;
EApp. Exp3 ::= Exp3 Exp4 ;
EAdd. Exp1 ::= Exp1 "+" Exp2 ;
ELet. Exp ::= "let" LIdent "=" Exp "in" Exp ;
EAbs. Exp ::= "\\" LIdent "." Exp ;
ECase. Exp ::= "case" Exp "of" "{" [Inj] "}";
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-- * LITERALS
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LInt. Lit ::= Integer ;
LChar. Lit ::= Char ;
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-- * CASE
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Inj. Inj ::= Init "=>" Exp ;
InitLit. Init ::= Lit ;
InitConstructor. Init ::= UIdent [LIdent] ;
InitCatch. Init ::= "_" ;
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-- * AUX
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separator Def ";" ;
separator nonempty Constructor "" ;
separator Type " " ;
separator nonempty Inj ";" ;
separator Ident " ";
separator LIdent " ";
coercions Exp 5 ;
coercions Type 2 ;
token UIdent (upper (letter | digit | '_')*) ;
token LIdent (lower (letter | digit | '_')*) ;
comment "--" ;
comment "{-" "-}" ;