how to add white space

[zrwsmd]

my langium file is below
demo.txt
how to add whitespace between 'IF' and 'THEN'

[msujew]

Hey @zrwsmd,

you're probably looking for our formatting guide. Formatting is the preferred way of ensuring that most reasonable white space rules are satisfied.

[zrwsmd]

i mean when i validate a st file like

IF state > 9THEN
//operation
END_IF

it should report error
since this st file is written by user,so they can write maybe without whitespace

[msujew]

You can write a validation rule that ensures this based on the CST:

checkWhitespace(ifStatement: IfStatement, acceptor: ValidationAcceptor): void {
  const text = (getDocument(ifStatement).parseResult.value.$cstNode as RootCstNode).fullText;
  const thenKeyword = GrammarUtils.findNodeForKeyword(ifStatement.$cstNode, 'THEN');
  if (thenKeyword) {
    const index = thenKeyword.offset;
    const previousChar = text.charAt(index - 1);
    if (previousChar !== ' ') {
      acceptor('error', ...);
    }
  }
}

[zrwsmd]

for elsifConditions,it may have more than one condition like this,

if i write like this code,

it only validate first scrrenshot error part,can not validate later 'THEN',even i change GrammarUtils.findNodeForKeyword third param to 4,5....

[msujew]

There is also a findNodesForKeyword function available that gives you all nodes.

[zrwsmd]

i have noticed this function,but seems did not work,only validate first 'THEN' appear position

IF state > 9 THEN
state := 1 / 8;
ELSIF state > 20 THEN
state := 2;
ELSIF state > 50 THEN
state := 5;
ELSIF state > 70 THEN
state := 7;
ELSE
state := 3;
END_IF;

[msujew]

Well you are applying it to the same property, so it will always position the error message at the same position. Use the index property to select at which index of the property the error is supposed to appear.