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;; [sp21.sty] Context-free grammar for the STEP exchange format, ISO 10303 Part 21
Language sp21 ;; STEP exchange format, ISO 10303 Part 21
Regular Grammar
; Character Set
let Byte = '\00' .. '\ff' ; all extended ascii
let Control = '\00' .. '\1f' ; control
| '\7f' ; DEL
| '\ff' ; space-like extended ascii
; Basic elements of tokens
let Printable = Byte - Control
ign Space = " " | "\t" ; ASCII - Space
ign Line = "\n" | "\r" ; UNIX / Windows / DOS / Mac
ign Page = "\p" ; weak separation convention
ign Etx = "\1a" {Byte} ; CPM / older DOS Versions
; Definitions and simple tokens
let ULetter = 'A'..'Z' | '_'
let LLetter = 'a'..'z'
let Letter = ULetter | LLetter
let Hex1 = '0'..'9' | 'a'..'f' | 'A' .. 'Z'
let Hex2 = Hex1 Hex1
let Hex4 = Hex2 Hex2
let Digit = '0'..'9'
let Special = '!\"*$%&.#+,-()?/:;<=>@[]{}|^~\`'
let Character = Letter | Digit | Special | ' ' | '\'' | '\\'
let Directive = ( "\\P" ULetter "\\" )
| ( "\\S\\" Character )
| ( "\\X" Hex1 "\\" )
| ( "\\X2\\" Hex2 { Hex2 } "\\X0\\" )
| ( "\\X4\\" Hex4 { Hex4 } "\\X0\\" )
let LitChar = Letter | Digit | Special | ' ' | "\'\'" | "\\\\" | Directive
let Sign = "+" | "-"
let Nat = Digit { Digit }
let Alpha = ULetter { ULetter | Digit }
; Comments et al
com Comment = "/*" ({Byte}-({Byte}"*/"{Byte})) "*/"
| "//" ({Byte}-({Byte} Line {Byte})) Line
; Complex tokens
tok Key = [ "!" ] Alpha ; KEYWORD
tok Enum = "." Alpha "." ; ENUMERATION
tok Ide = "#" Nat ; ENTITY_INSTANCE_NAME
tok Int = [ Sign ] Nat ; INTEGER
tok Flt = [ Sign ] Nat "." { Digit }
[ "E" [ Sign ] Nat ] ; REAL
tok Str = '\'' {LitChar} '\'' ; STRING
tok Bin = "\""
( "0" | "1" | "2" | "3" )
{ Hex1 } "\"" ; BINARY
tok Opr = '(),;=*$'
| ( [ "END-" ] "ISO-10303-21;" )
| "HEADER;"
| "ENDSEC;" ; Operator
Context Free Grammar
start Step21
:root: "ISO-10303-21;" HdrSec DataSecs "END-ISO-10303-21;"
let HdrSec
:dfn : "HEADER;" HdrEntities "ENDSEC;" ; min. 3 elements
let HdrEntities
:cons: HdrEntity HdrEntities2
let HdrEntities2
:cons: HdrEntity HdrEntities1
let HdrEntities1
:cons: HdrEntity HdrEntities0
let HdrEntities0
:nil :
:cons: HdrEntity HdrEntities0
let DataSecs
:cons: DataSec DataSecs0
let DataSecs0
:nil :
:cons: DataSec DataSecs0
let HdrEntity
:dfn : Key "(" Params ")" ";"
let Params0
:nil :
:cons: "," Param Params0
let Params
:nil :
:ign0: Params1
let Params1
:cons: Param Params0
let Params2
:nil :
:ign0: "(" Params1 ")"
let Param
:typ : Key "(" Param ")"
:null: "*"
:opt : "$"
:ide : Ide
:int : Int
:flt : Flt
:str : Str
:bin : Bin
:enum: Enum
:list: "(" Params ")"
let DataSec
:dfn : "DATA" Params2 ";" Instances "ENDSEC;"
let Instances
:nil :
:cons: Instance Instances
let Instance
:dfn : Ide "=" Record ";"
let Record0
:srec: Key "(" Params ")"
let Record
:crec: "(" SRecords ")"
:ign0: Record0
let SRecords
:cons: Record0 SRecords0
let SRecords0
:nil :
:cons: Record0 SRecords0
|
