VDM-10 Language Manual

VDM-10 Language Manual
is basic type = ‘is ’, ( ‘bool’ | ‘nat’ | ‘nat1’ | ‘int’ | ‘rat’
| ‘real’ | ‘char’ | ‘token’ ) ;
symbolic literal = numeric literal | boolean literal
| nil literal | character literal | text literal
| quote literal ;
numeral = digit, { digit } ;
numeric literal = decimal literal | hexadecimal literal ;
exponent = ( ‘E’ | ‘e’ ), [ ‘+’ | ‘-’ ], numeral ;
decimal literal = numeral, [ ‘.’, digit, { digit } ], [ exponent ] ;
hexadecimal literal = ( ‘0x’ | ‘0X’ ), hexadecimal digit, { hexadecimal digit } ;
boolean literal = ‘true’ | ‘false’ ;
nil literal = ‘nil’ ;
character literal = ‘ ’ ’, character | escape sequence
| ‘ ’ ’ ;
escape sequence = ‘\\’ | ‘\r’ | ‘\n’ | ‘\t’ | ‘\f’ | ‘\e’ | ‘\a’
| ‘\x’ hexadecimal digit,hexadecimal digit
| ‘\u’ hexadecimal digit,hexadecimal digit, hexadecimal digit,hexadecimal digit
| ‘\c’ character
| ‘\’ octal digit, octal digit, octal digit
| ‘\"’ | ‘\’’ | ;
text literal = ‘ " ’, { ‘ \" ’ | character | escape sequence }, ‘ " ’ ;
quote literal = ‘’ ;
Single-line comment = ‘--’, { character – newline }, newline ;
Multiple-line comment = ‘/*’, { character }, ‘*/’ ;
The escape sequences given above are to be interpreted as follows:
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