various use cases for ruby blocks

proc_expectations.rb

require 'rubygems'
require 'expectations'

Expectations do

expect(1){ proc{ |a| a }.call(1) }
expect([1, 2]){ proc{ |a| a }.call(1, 2) }
expect(1){ proc{ |a, b| a }.call(1, 2) }

expect(1){ Proc.new{ |a| a }.call(1) }
expect([1, 2]){ Proc.new{ |a| a }.call(1, 2) }
expect(1){ Proc.new{ |a, b| a }.call(1, 2) }

def foo
    x = proc { return :block }
    x.call()
    return :method
end

expect foo().to.be == :method

def bar
    x = Proc.new { return :block }
    x.call()
    return :method
end

expect bar().to.be == :block

=begin
def boo
    yield :block
    return :method
end

# does not compile as return not allowed in implicit block
expect boo{ |a| return a }.to.be == :method

def baz &block
    block.call(:block)
    return :method
end

# not even when block param is explicitly declared in method
expect baz{ |a| return a }.to.be == :block
=end

end

dexter@dexters-lab01:~/repo/847115$ /opt/ruby/1.8.7-p330/bin/ruby proc_expectations.rb 2>err && cat err
Expectations ........
Finished in 0.00744 seconds

Success: 8 fulfilled
proc_expectations.rb:7: warning: multiple values for a block parameter (2 for 1) from proc_expectations.rb:7
proc_expectations.rb:11: warning: multiple values for a block parameter (2 for 1) from proc_expectations.rb:11

dexter@dexters-lab01:~/repo/847115$ /opt/ruby/1.9.2-p136/bin/ruby proc_expectations.rb 2>err && cat err
Expectations .F..F.F.
Finished in 0.00706 seconds

Failure: 3 failed, 0 errors, 5 fulfilled

--Failures--
file <proc_expectations.rb>
line <7>
expected: <[1, 2]> got: <1>

file <proc_expectations.rb>
line <11>
expected: <[1, 2]> got: <1>

file <proc_expectations.rb>
line <20>
expected block to be == :method