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Literals

Summary:

• Integer Literals
• Decimal Literals
• String Literals
• Datetime Literals
• Interval Literals

See also: Variables, Data Types, Expressions.

INTEGER LITERALS

Purpose:

The language supports integer literals in base-10 notation, without blank spaces and commas and without a decimal point.

Syntax:

Notes:

1. digit is a digit character from '0' to '9'.

Usage:

Example:

01 MAIN
02   DEFINE n INTEGER 
03   LET n = 1234567
04 END MAIN

DECIMAL LITERALS

Purpose:

The language supports decimal literals as a base-10 representation of a real number, with an optional exponent notation.

Syntax:

Notes:

1. dot is the decimal separator and is always a dot, independently from DBMONEY.
2. The E character is used to specify the exponent.

Example:

01 MAIN
02   DEFINE n DECIMAL(10,2)
03   LET n = 12345.67
04   LET n = -1.23456e-10
05 END MAIN

STRING LITERALS

Purpose:

The language supports string literals delimited by single quotes or double quotes.

Syntax 1 (using double quotes):

Syntax 2 (using single quotes):

Usage:

A string literal can be written on multiple lines, the compiler merges lines by removing the new-line character.

The escape character is the back-slash character (\).

Quotes can be doubled to be included in strings.

An empty string ("") is equivalent to NULL.

Escape Sequences in string literals

1. \\ is a backslash character.
2. \" is a double-quote character.
3. \' is a single-quote character.
4. \n is a new-line character.
5. \r is a carriage-return character.
6. \0 is a null character.
7. \f is a form-feed character.
8. \t is a tab character.
9. \xNN is a character defined by the hexadecimal code NN.

Example:

01 MAIN
02   DISPLAY "Some text in double quotes"
03   DISPLAY 'Some text in single quotes'
04   DISPLAY "Escaped double quotes :  \"  ""  "
05   DISPLAY 'Escaped single quotes :  \'  ''  '
06   DISPLAY 'Insert a new-line character here: \n and continue with text.'
07   DISPLAY "This is a text
08    on multiple
09    lines.\
10    You can insert a new-line with back-slash at the end of the line."
11   IF "" IS NULL THEN DISPLAY 'Empty string is NULL' END IF
12 END MAIN

DATETIME LITERALS

Purpose:

The language supports datetime literals with the DATETIME () notation.

Syntax:

Notes:

1. dtrep is the datetime value representation in normalized format (YYYY-MM-DD hh:mm:ss.fffff).
2. qual1 and qual2 are the datetime qualifiers as described in the Datetime data type.

Example:

01 MAIN
02   DEFINE d1 DATETIME YEAR TO SECOND
03   DEFINE d2 DATETIME HOUR TO FRACTION(5)
04   LET d1 = DATETIME ( 2002-12-24 23:55:56 ) YEAR TO SECOND
05   LET d2 = DATETIME ( 23:44:55.34532 ) HOUR TO FRACTION(5)
06 END MAIN

INTERVAL LITERALS

Purpose:

The language supports interval literals with the INTERVAL() notation.

Syntax:

Notes:

1. inrep is the interval value representation in normalized format (YYYY-MM or DD hh:mm:ss.fffff).
2. qual1 and qual2 are the interval qualifiers as described in the Interval data type..

Example:

01 MAIN
02   DEFINE i1 INTERVAL YEAR TO MONTH
03   DEFINE i2 INTERVAL HOUR(5) TO SECOND
04   LET i1 = INTERVAL ( 345-5 ) YEAR TO MONTH
05   LET i2 = INTERVAL ( 34562:22:33 ) HOUR(5) TO SECOND
06 END MAIN