Outline

Language "IMPPP"

1 Values

Integers

Syntax
  N : int ::= '-'^?_decimal
Lexis
  D : decimal ::= ('0'-'9')⁺

Semantics
  int-val[[ _:int ]] : =>integers
Rule
  int-val[[ D ]] = decimal-natural(\"D\")
Rule
  int-val[[ '-' D ]] = integer-negate(int-val[[ D ]])

Syntax
  S : string ::= '"'_string-chars_'"'
Lexis
  SCS : string-chars ::= (~'"')^*

Semantics
  string-val[[ _:string ]] : =>strings
Rule
  string-val[[ '"' SCS '"' ]] = \"SCS\"

Lexis
  I : id ::= ('A'-'Z'|'a'-'z'|'_') ('0'-'9'|'A'-'Z'|'a'-'z'|'_')^*

Semantics
  id[[ _:id ]] : =>ids
Rule
  id[[ I ]] = \"I\"

Lexis
  keyword ::= 'else'  | 'false' | 'if'    | 'halt' | 'join' 
            | 'print' | 'read'  | 'spawn' | 'true' | 'while'