Class: Opal::Nodes::XStringNode

Inherits:
Base
  • Object
show all
Defined in:
opal/lib/opal/nodes/x_string.rb

Instance Attribute Summary

Attributes inherited from Base

#compiler, #sexp, #type

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#add_gvar, #add_ivar, #add_local, #add_temp, #children, children, #class_variable_owner, #class_variable_owner_nesting_level, #comments, #compile_to_fragments, #error, #expr, #expr?, #expr_or_nil, #fragment, handle, handlers, #has_rescue_else?, #helper, #in_ensure, #in_ensure?, #in_resbody, #in_resbody?, #in_rescue, #in_while?, #initialize, #process, #push, #recv, #recv?, #s, #scope, #source_location, #stmt, #stmt?, #top_scope, truthy_optimize?, #unshift, #while_loop, #with_temp, #wrap

Methods included from Helpers

#current_indent, #empty_line, #indent, #js_truthy, #js_truthy_optimize, #line, #mid_to_jsid, #property, #valid_name?

Constructor Details

This class inherits a constructor from Opal::Nodes::Base

Class Method Details

.single_line?(children) ⇒ Boolean

Check if there's only one child or if they're all part of the same line (e.g. because of interpolations)

Returns:

  • (Boolean) 


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# File 'opal/lib/opal/nodes/x_string.rb', line 35

def self.single_line?(children)
  (children.size == 1) || children.none? do |c|
    c.type == :str && c.loc.expression.source.end_with?("\n")
  end
end

.strip_empty_children(children) ⇒ Object

Will remove empty :str lines coming from cosmetic newlines in x-strings

Examples:

# this will generate two additional empty
# children before and after `foo()`
%x{
  foo()
}


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# File 'opal/lib/opal/nodes/x_string.rb', line 49

def self.strip_empty_children(children)
  children = children.dup
  empty_line = ->(child) { child.nil? || (child.type == :str && child.loc.expression.source.rstrip.empty?) }

  children.shift while children.any? && empty_line[children.first]
  children.pop while children.any? && empty_line[children.last]

  children
end

Instance Method Details

#compile ⇒ Object 



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# File 'opal/lib/opal/nodes/x_string.rb', line 8

def compile
  @should_add_semicolon = false
  unpacked_children = unpack_return(children)
  stripped_children = XStringNode.strip_empty_children(unpacked_children)

  if XStringNode.single_line?(stripped_children)
    # If it's a single line we'll try to:
    #
    # - strip empty lines
    # - remove a trailing `;`
    # - detect an embedded `return`
    # - prepend a `return` when needed
    # - append a `;` when needed
    # - warn the user not to use the semicolon in single-line x-strings
    compile_single_line(stripped_children)
  else
    # Here we leave to the user the responsibility to add
    # a return where it's due.
    unpacked_children.each { |c| compile_child(c) }
  end

  wrap '(', ')' if recv?
  push ';' if @should_add_semicolon
end