Atomic Literal Expressions

Atomic literal expressions are expressions composed of a single terminal (or token or lexical unit) without any operator. They are also called primary expressions. These expressions have already been introduced in Section 5.1.

General Information
Operator	no operator
Type	unary
Syntax	terminal atom
Operand Types	integer, float, char, string, boolean, identifier, null, nil, oid,
Result Type	same type as the operand

Expression Examples
expression	result
1	1
2.	12.
'a'	'a'
"hello"	"hello"
alpha	value of alpha
true	true
83283.1.29292:oid	an error is raised in case of the oid is invalid.
	Otherwise the result is the input oid: 83283.1.29292:oid