Server Load Balancer:AScript syntax

Syntax

Description

Annotation

All annotations must start with a number sign (#). Example: # this is annotation.

Identifier

• Identifiers are case-sensitive. An identifier can contain letters, digits, and underscores (_). It cannot start with a digit.

• All names of built-in variables, custom variables, built-in functions, and custom functions must comply with the identifier conventions.

Data type

• String

  Literal constants: Use a pair of single quotation marks (') to quote a literal constant, for example, 'hello, AScript'.

• Numeric

  Literal constants: decimal numbers, for example, 10, -99, or 1.1.

• Boolean

  Literal constants: true or false.

• Dictionary

  Literal constants:

  • []: an empty string.

  • ['key1', 'key2', 100]:

    • 1 -> 'key1'

    • 2 -> 'key2'

    • 3 -> 100

  • ['key1' = 'value1', 'key2' = 1000]

    • 'key1' -> 'value1'

    • 'key2' -> 1000

Variable

• Definition

  A variable is a symbolic name associated with a value that may change.

• How to use

  • Both built-in and custom variables are referenced by using their names.

    • Reference a built-in variable: host.

    • Reference a custom variable: seckey.

  • To specify that a variable is a built-in variable, add a dollar sign ($) before the variable name.

    Reference a built-in variable: $host.

  • A custom variable and a built-in variable cannot use the same name.

    For more information about built-in variables, see Built-in variables.

Operator

• =: the assignment operator.

  • Example: seckey = 'ASDLFJ234dxvf34sDF'

  • Example: seckeys = ['key1', 'key2']

• -: the minus operator.

  Example: inum = -10

• Built-in functions are used to process different types of data. No additional operators are provided. For more information about built-in functions, see AScript functions.

Clause

• Condition clause

  if condition {   
     ...
  }
  
  if condition1 {   
     if condition2 {
          ...
     }
  }
  
  if condition {
     ...
  } else {
     ...
  }

• Clause descriptions

  • A condition clause contains the following elements:

    • Literal constant

    • Variable

    • Function call

  • Body

    • The body can be empty.

    • Multiple statements are allowed. Enter only one statement on each line.

  • Statement nesting is allowed.

  • Coding style

    The opening brace ({) must follow if condition on the same line.

Function

• Syntax

  def Function name(Parameter list) {
      ...
  }

• Descriptions

  • Parameter list

    • The parameter list can be empty.

    • Multiple parameters are allowed. Separate parameters with commas (,).

  • Body

    • The body can be empty.

    • Multiple statements are allowed. Enter only one statement on each line.

    • The return values support the return clause.

  • Coding style

    The opening brace ({) must follow def Function name(Parameter list) on the same line.

• Function call

  You must use Function name(Parameter list) to call built-in and custom functions.