function(ast) {
    let value = this.value;

    ast.traverseByType('space', function(space) {
      space.content = space.content.replace(/\t/, value);
    });
  }
function(ast) {
    let value = this.value;

    ast.traverseByType('space', function(space) {
      space.content = space.content.replace(/\t/, value);
    });
  }
function ( ast ) { let value = this . value ; ast . traverseByType ( 'space' , function ( space ) { space . content = space . content . replace ( / \t / , value ) ; } ) ; }
Processes tree node.

@param {node} ast
Processes tree node .