Harulang is a simple scripting language for visual novels.

config
  let resource-directory =  "/resources"
end config
character reimu
  let name = "Reimu Hakurei"
  let img = "/img/reimu"
end character
character marisa
  let name = "Marisa Kirisame"
  let img = "/img/marisa"
end character
global
  let san = 6
end global
scene main
  show background "/img/hakurei-shrine.jpg"
  show reimu at left
  show marisa at right
  marisa happy "This is a line spoken by Marisa"
  reimu happy "This is a line spoken by Reimu"
  for i = 0 to 10
    aside "This is a for loop, now i = ${i}"
  end for
  select
    choice "Choice 1"
      let san = san - 1
    end choice
    choice "Choice 2"
      let san = san + 1
      jump scene1_1
    end choice
  end select
  if san < 6
    aside "Your san is less than 6"
  end if
end scene

These words have syntatic meaning and cannot be used as identifiers.

Identifiers begin with an underscore _ or a latin letter, and may contain only numbers, letters, and underscores. Identifiers cannot be reserved words.

For example: Hey __gcd getElementById1 are valid identifiers, 1AA a12-34 let are not.

An assignment is defined as follows

<assignment> ::= "let" <identifier> "=" <expressions>

For example:

let a = 10
let b = "A string"

Harulang does not have a dedicated variable definition structure, a variable becomes "defined" when it is first assigned a value. Harulang is dynamically typed - variables do not hold types, only values, thus the following line is valid:

let a = 10
let a = "10"

If you attempt to use a variable without defining it first, it defaults to integer literal 0.

Expressions in Harulang are similar to that in most programming languages.

Here are some distinctions that may need notice:

• Exponetion operator is ^, integer division operator is \
• Bit manipulation is not required
• To test for equality, use == or ===. In == type casting is done (see appendix for notes on type casting), while === tests for strict equality.
• To test for inequality, the <> operator (instead of !=) is used. This design idea came from Visual Basic.
• The logical opertors are and or not xor, as in Python.

String literals are enclosed in double quotes.

In string literals, variables may be substituted with the ${var} syntax, for example:

let a = 10
aside "Variable a is set to ${a}"

Number literals may be written in aEb notation, where a is a floating point and b is an integer.

The program contains four parts: config, character, global and scene. They may be omitted but must appear in this order.

Config items go into the config ... end config block, and is a list of assignments.

Configuration items themselves are implementation-defined and will not be documented here.

Character definition go into the character ... end character block, and is a list of assignments.

Character configuration items themselves are implementation-defined and will not be documented here.

Global variables go into the global ... end global block, and is a list of assignments.

Scenes are a collection of instructions. Instructions may themselves be blocks (namely, if ... elseif ... else ... end if blocks, for ... end for blocks, and while ... end while blocks)

If an instruction does not begin with a reserved word, it is treated as a line of the character and must be followed by a string literal containing the line to be spoken.

The following documents special instructions that begin with reserved words.