>>>>> Johann Hibschman <johann at physics.berkeley.edu> (JH) writes:
JH> Steven D Majewski writes:
>>> class Foo < Bar
>>> def myMethod
>>> File.new ("test.dat", "w") { |f|
>>> f.puts "Hello world!"
>>> }
>>> end
>>> end
>> What do the vertical bars around the f ("|f|") above indicate ?
JH> That indicates that the block takes one argument, which is named "f".
In other words, a lambda expression.
JH> In Python, this would be:
In Python you could then also use the lambda expression.
lambda f: f.puts("Hello World") or write rather than puts
JH> def File_new (filename, func_to_call):
JH> try:
JH> file_obj = open (filename, 'w')
JH> func_to_call (file_obj)
JH> finally:
JH> file_obj.close()
JH> def block_function (f): # i.e. this is what that |f| means...
JH> f.write ("Hello, world!\n")
JH> File_new ("test.dat", block_function)
What about open("test.dat", "w").write ("Hello world")?
--
Piet van Oostrum <piet at cs.uu.nl>
URL: http://www.cs.uu.nl/~piet [PGP]
Private email: P.van.Oostrum at hccnet.nl
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4