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Code Block Style

Code Blocks Languages typically use either a block-structured (Delimiter) or whitespace / indentation style of code blocks. LARF supports both of these using config.setProperty(DefaultProperty.CODE_BLOCK_STYLE, CodeBlockStyle.*) with the possible values:

  • CodeBlockStyle.DELIMITER
  • CodeBlockStyle.WHITESPACE_FIXED
  • CodeBlockStyle.WHITESPACE_IDENTIFY

Delimiter​

Delimiter-based code blocks are the most common with either a keyword or character representing the beginning of end. Here is an example of a code block in C / C++ / Java:

if (2 > 1) {
    //...
}

It uses an opening and closing curly brace to represent this. To show some other examples, here is Pascal:

if 2 > 1 then
begin
    //...
end;

This is the default code-block style within LARF and needs no further configuration other than to set up your token.

Whitespace​

Whitespace based code-blocks is where the language uses indentation or "whitespace" characters (spaces / tabs) to identify blocks of code. Python and Haskell are examples of languages that uses idententation. They allow a user to define their own indentation value, but it has to be consistent. This would match the CodeBlockStyle.WHITESPACE_IDENTIFY value:

def greet(name):
    if name:
        greeting = "Hello, " + name + "!"
        print(greeting)
    else:
        print("Hello, there!")

greet("Alice")

If you are not consistent with the indentation, like with Python LARF will throw an indentation error. For example, running the following:

int i = 1
if i == 1 then
    i = 2
     if i == 2 then
        i = 3
        if i == 3 then
            int j
return i

Will give the following error:

Invalid whitespace used on line 4. Ensure code is uniformly indented using 4 spaces

The 4 spaces was the value taken from the initial indentation and was the rule that the following code must adhere to. If you wish to use a predefined indentation instead of automatic identification, you can use the CodeBlockStyle.WHITESPACE_FIXED and customize the whitespace value by using setProperty(DefaultProperty.WHITESPACE_VALUE, "\t| ");. The value may consist of one or more indentation values separated by a | character.