A syntax diagram describes the context-free, abstract grammar of a product function.
A syntax diagram for example describes a language instruction, the structure of a configuration file, or the options of command-line tool.
The following rules are used in a syntax diagram:
- Invariable syntax elements (keywords) are written in
fixed font. - Language keywords are in uppercase, like INPUT BY NAME.
- Variable syntax elements are written in italics.
- Wildcard characters are used to indicate syntax elements that can either repeat, be mandatory or optional.
| Wildcard character | Description | Example |
|---|---|---|
[ element ] |
Square brackets indicate an optional element in the syntax. | IS [NOT] NULL |
| [`element1`` | *element2*...`] |
Square brackets with pipe separator indicate an optional element to be selected from the list. |
{element1` |
*element2*...`} |
Curly brackets with pipe separator indicate a mandatory element to be selected from the list. |
[ ... ] |
A sign made of square brackets with three dots indicate that the previous element can appear more than once. | ident [...] |
[ ,... ] |
A sign made of square brackets with a comma followed by three dots indicate that the previous element can appear more than once, and must be separated by a comma. | colname [,...] |
For example, this is the URL for the Genero DeploymentApp:
http[s]://server:port>[/gas]/ua/r/admin/DeploymentApp
server,port, andgasare variables.[gas]is optional.