Syntax notation
Statements, methods, and functions are described with syntax diagrams. These syntax diagrams consist of a least one fixed language element—the one being documented—and may include arguments, which are enclosed in angle brackets (< >).
The dBL language is not case-sensitive.
The following table describes the symbols used in syntax:
Symbol |
Description |
< > |
Indicates an argument that you must supply |
[ ] |
Indicates an optional item |
| |
Indicates two or more mutually exclusive options |
... |
Indicates an item that may be repeated any number of times
|
Arguments are often expressions of a particular type. The description of an expression argument will indicate the type of argument expected, as listed in the following table:
Descriptor |
Type |
expC |
A character expression |
expN |
A numeric expression |
expL |
A logical or boolean expression; that is, one that evaluates to true or false |
expD |
A date expression |
exp |
An expression of any type |
oRef |
An object reference |
All the arguments and optional elements are described in the syntax description.
Unlike legacy dBASE command and function keywords, which are shown in uppercase letters, property names are capitalized differently. Property names are camel-capped, that is, they contain both uppercase and lowercase letters if the name consists of more than one word. If the property is a method, the name is followed by parentheses. Examples of properties include onAppend, onRightMouseDown, checked, and close( ).
These conventions help you differentiate the language elements; for example,
DELETE is a command
delete is a property
DELETED( ) is a function
delete( ) is a method
These typographical conventions are for readability only. When writing code, you can use any combination of uppercase and lowercase letters.
Note
In dBL, you must refer to classes and properties by their full names. However, you can still abbreviate some keywords in the dBL language to the first four characters, though for reasons of readability and clarity such abbreviation is not recommended.