Core-2 grammar

(* Core-2 overlay on Core-1 and Core-0. Replace domain/effect/unary-operator below.
   Append component-declaration, physical-model-declaration and
   realization-declaration to implementation-top-level-declaration.
   Append hardware-type and physical-type to type. Other productions retain
   their inherited meaning. New declaration keywords are contextual only in
   these productions; they do not reinterpret old-edition identifiers.
   expression, type, visibility, identifier, authoring-modality,
   integer-literal and string-literal are inherited. Physical expressions
   use the inherited expression syntax with the pure mathematical typing in
   C2-PHYS-004, not software assignment/effect semantics. *)

domain = "algorithm" | "compute" | "state" | "flow" | "optimize" | "hardware" ;
effect = "io" | "alloc" | "time" | "random" | "reflect" | "unsafe"
       | "abort" | "compute" | "state" | "flow" | "optimize"
       | "hardware" | "physics" ;
unary-operator = "!" | "-" | "~" ;
(* Make C1-MOD-001 explicit for the inherited value-specific production too.
   Value messages retain Core-0's sealed, block-bodied member shape; portable
   templates retain the Core-1 domain-set and per-message modality. *)
value-message-declaration = visibility , authoring-modality ,
    ( domain | "portable" , domain-set ) , "message" , message-selector ,
    [ generic-parameters ] , "(" , receiver-parameter ,
    [ "," , value-parameter-list ] , ")" , "->" , type ,
    { requirement-clause } , [ precondition-clause ] , [ postcondition-clause ] ,
    effect-clause , block ;
qualified-name = identifier , { "." , identifier } ;
width = integer-literal | identifier ;
hardware-type = "Bit" | "Logic" | "Clock" | "Reset"
              | ( "Bits" | "Logic" ) , "<" , width , ">"
              | "Hardware" , "<" , qualified-name , ">" ;
physical-type = ( "Quantity" | "Scalar" | "Vector" | "Tensor" ) ,
                "<" , qualified-name , ">"
              | "SolverPlan" , "<" , qualified-name , ">" ;
binding = identifier , "=" , expression ;
bindings = "(" , [ binding , { "," , binding } ] , ")" ;

component-declaration = visibility , authoring-modality , "hardware" ,
    "component" , identifier , [ static-parameters ] ,
    "(" , [ port , { "," , port } ] , ")" , "{" , { component-item } , "}" ;
static-parameters = "<" , identifier , ":" , "Index" ,
                    { "," , identifier , ":" , "Index" } , ">" ;
port = ( "in" | "out" | "inout" ) , identifier , ":" , type ;
component-item = net-declaration | instance-declaration | clock-declaration
               | region-declaration | bridge-declaration | fact-declaration
               | observation-declaration ;
net-declaration = "net" , identifier , ":" , type ,
                  [ "resolve" , qualified-name ] , ";" ;
instance-declaration = "instance" , identifier , ":" , qualified-name ,
                      [ "<" , width , { "," , width } , ">" ] , bindings , ";" ;
clock-declaration = "clock" , identifier , "=" , ( "rising" | "falling" ) ,
    "(" , qualified-name , ")" , [ "reset" , qualified-name ,
    "active" , ( "high" | "low" ) , "mode" ,
    ( "synchronous" | "asynchronous" ) ] , ";" ;
discipline = "combinational" | "clocked" | "asynchronous" | "intrinsic" ;
region-declaration = "region" , identifier , ":" , discipline , "{" ,
                     { region-item } , "}" ;
region-item = connection | register-declaration | async-state-declaration
            | process-declaration | fact-declaration ;
connection = "connect" , qualified-name , "=" , expression , ";" ;
register-declaration = "register" , identifier , ":" , type ,
                       "on" , identifier , "=" , expression , ";" ;
async-state-declaration = "state" , identifier , ":" , type , "=" , expression , ";" ;
process-declaration = "process" , identifier ,
    ( "on" , identifier | "when" , expression ) , "{" ,
    { ( "next" | "drive" ) , qualified-name , "=" , expression , ";" } , "}" ;
fact-declaration = ( "constraint" | "assume" ) , identifier , "=" , expression , ";" ;
bridge-declaration = "bridge" , identifier , ":" , qualified-name , bindings , ";" ;
observation-declaration = "observe" , identifier , "=" , expression , ";" ;

physical-model-declaration = visibility , "physical" , "model" , identifier ,
                            "{" , { model-item } , "}" ;
model-item = mesh-declaration | parameter-declaration | model-field
           | material-declaration | equation-declaration | condition-declaration
           | analysis-declaration | coupling-declaration | bridge-declaration
           | observation-declaration | fact-declaration ;
mesh-declaration = "mesh" , identifier , "=" , expression , ";" ;
parameter-declaration = "parameter" , identifier , ":" , type , "=" , expression , ";" ;
(* This model-field production is local to model-item; the inherited object
   field-declaration production is not replaced. *)
model-field = "field" , identifier , ":" , physical-type , "on" , qualified-name , ";" ;
material-declaration = "material" , identifier , "on" , qualified-name ,
                       "=" , expression , ";" ;
equation-declaration = "equation" , identifier ,
    ( "strong" | "weak" , "for" , identifier , "in" , qualified-name ) ,
    expression , ";" ;
condition-declaration = "condition" ,
    ( "initial" | "boundary" | "interface" | "source" ) , identifier ,
    "on" , qualified-name , "=" , expression , ";" ;
analysis-kind = "steady" | "transient" | "harmonic" | "eigenvalue" | "coupled" ;
analysis-declaration = "analysis" , identifier , ":" , analysis-kind ,
                      "{" , { fact-declaration | observation-declaration } , "}" ;
coupling-declaration = "couple" , identifier , ":" , qualified-name , bindings , ";" ;

realization-declaration = visibility , "realization" , identifier ,
    "refines" , qualified-name , "with" , qualified-name ,
    "profile" , ( discipline | analysis-kind ) , "claims" , claim , ";" ;
claim = "exact" | "bounded" , "(" , qualified-name , ")"
      | "statistical" , "(" , qualified-name , ")" ;