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%% Note: this SDF grammar is no longer used in the Nix expression
%% parser and may not be up to date.
definition
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Top level syntax.
module Main
imports Nix-Exprs Nix-Layout
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Expressions.
module Nix-Exprs
imports Nix-Lexicals
exports
sorts Expr Formal Bind ExprList
context-free start-symbols Expr
context-free syntax
Id -> Expr {cons("Var")}
Int -> Expr {cons("Int")}
Str -> Expr {cons("Str")}
Uri -> Expr {cons("Uri")}
Path -> Expr {cons("Path")}
"(" Expr ")" -> Expr {bracket}
Expr Expr -> Expr {cons("Call"), left}
Id ":" Expr -> Expr {cons("Function1")}
"{" {Formal ","}* "}" ":" Expr -> Expr {cons("Function")}
Id -> Formal {cons("NoDefFormal")}
Id "?" Expr -> Formal {cons("DefFormal")}
"assert" Expr ";" Expr -> Expr {cons("Assert")}
"with" Expr ";" Expr -> Expr {cons("With")}
"rec" "{" Bind* "}" -> Expr {cons("Rec")}
"let" Bind* "in" Expr -> Expr {cons("Let")}
"let" "{" Bind* "}" -> Expr {cons("LetRec")}
"{" Bind* "}" -> Expr {cons("Attrs")}
Id "=" Expr ";" -> Bind {cons("Bind")}
"inherit" ("(" Expr ")")? Id* ";" -> Bind {cons("Inherit")}
"[" ExprList "]" -> Expr {cons("List")}
-> ExprList {cons("ExprNil")}
Expr ExprList -> ExprList {cons("ExprCons")}
Expr "." Id -> Expr {cons("Select")}
"if" Expr "then" Expr "else" Expr -> Expr {cons("If")}
Expr "==" Expr -> Expr {cons("OpEq"), non-assoc}
Expr "!=" Expr -> Expr {cons("OpNEq"), non-assoc}
"!" Expr -> Expr {cons("OpNot")}
Expr "&&" Expr -> Expr {cons("OpAnd"), right}
Expr "||" Expr -> Expr {cons("OpOr"), right}
Expr "->" Expr -> Expr {cons("OpImpl"), right}
Expr "//" Expr -> Expr {cons("OpUpdate"), right}
Expr "~" Expr -> Expr {cons("SubPath"), non-assoc}
Expr "?" Id -> Expr {cons("OpHasAttr")}
Expr "+" Expr -> Expr {cons("OpPlus"), left}
Expr "++" Expr -> Expr {cons("OpConcat"), right}
context-free priorities
Expr "." Id -> Expr
> Expr ExprList -> ExprList
> Expr Expr -> Expr
> Expr "~" Expr -> Expr
> Expr "?" Id -> Expr
> Expr "++" Expr -> Expr
> Expr "+" Expr -> Expr
> "!" Expr -> Expr
> Expr "//" Expr -> Expr
> { Expr "==" Expr -> Expr
Expr "!=" Expr -> Expr
}
> Expr "&&" Expr -> Expr
> Expr "||" Expr -> Expr
> Expr "->" Expr -> Expr
> "if" Expr "then" Expr "else" Expr -> Expr
> "assert" Expr ";" Expr -> Expr
> "with" Expr ";" Expr -> Expr
> Id ":" Expr -> Expr
> "{" {Formal ","}* "}" ":" Expr -> Expr
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Lexical syntax.
module Nix-Lexicals
exports
sorts Id Int Str Path Uri
lexical syntax
[a-zA-Z\_][a-zA-Z0-9\_\']* -> Id
"rec" | "let" | "if" | "then" | "else" | "assert" | "with" | "inherit" -> Id {reject}
[0-9]+ -> Int
"\"" (~[\"\\] | ("\\" ~[]) )* "\"" -> Str
"''" (~[\"\\] | ("\\" ~[]) )* "''" -> Str
[a-zA-Z0-9\.\_\-\+]* ("/"[a-zA-Z0-9\.\_\-\+]+)+ -> Path
[a-zA-Z] [a-zA-Z0-9\+\-\.]* ":" [a-zA-Z0-9\%\/\?\:\@\&\=\+\$\,\-\_\.\!\~\*\']+ -> Uri
lexical restrictions
Id -/- [a-zA-Z0-9\_\']
Int -/- [0-9]
Path -/- [a-zA-Z0-9\.\_\-\+\/]
Uri -/- [a-zA-Z0-9\%\/\?\:\@\&\=\+\$\,\-\_\.\!\~\*\']
"rec" "let" "if" "then" "else" "assert" "with" "inherit" -/- [A-Za-z0-9\_\']
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Layout.
module Nix-Layout
exports
sorts HashComment Asterisk Comment
lexical syntax
[\ \t\n] -> LAYOUT
HashComment -> LAYOUT
Comment -> LAYOUT
"#" ~[\n]* -> HashComment
"/*" ( ~[\*] | Asterisk )* "*/" -> Comment
[\*] ~[\/] -> Asterisk
lexical restrictions
HashComment -/- ~[\n]
context-free restrictions
LAYOUT? -/- [\ \t\n\#]
LAYOUT? -/- [\/].[\*]
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