Language Basics

Functions

export fn add(x, y) = x + y

export fn greet(name, title = 'Mx')
  return "#{title} #{name}"
end

Functions can accept blocks with &blk and invoke them with yield(...).

If no block is given, yield(...) returns nil instead of raising an error. That makes fallback patterns like this work cleanly:

export fn greet(name, title = 'Mx', **opts, &blk)
  prefix = opts.prefix || ''
  label = prefix + title + ' ' + name
  return yield(label) or label
end

greet(name='Ada')
greet(name='Ada') do |label|
  return label + '!'
end

Classes

export class User(name, age)
  greet() = "hi #{self.name}"
end

Control Flow

if ready
  print('go')
elsif fallback
  print('fallback')
else
  print('wait')
end

unless failed
  print('ok')
end

case value
when 1
  return 'one'
when 2, 3
  return 'many'
else
  return 'other'
end

Pattern Matching

match value
when User(_, age)
  return age
when User()
  return 'user'
else
  return 'other'
end

Strings

name = 'Ada'
line = "Hello #{name}"
text = """
Hello #{name}
Line 2
"""

Arrays and Hashes

items = [1, 2, 3]
user = {name = 'Ada', age = 9}

Jaya supports negative indexing and slicing for arrays and strings:

items[-1]
items[2..-1]
'Jaya'[1...-1]