On Aug 23, 2006, at 10:16 AM, George Young wrote:
[linux, ghci 6.4.3.20060820, hugs May 2006]
I have just started learning Haskell. I have hugs and ghci under linux, and I'm going through the Gentle Introduction to Haskellhttp://www.haskell.org/tutorial, so far through section 4, "case expressions and pattern matching". I'm a python programmer, with background in maclisp, scheme, T, C, C++, and a little J.
I'm confused about what sort of things I can type at the interpreter prompt, and what things have to be loaded as a module. I keep trying to treat the prompt like a lisp or python REPL, which is obviously wrong. Can someone set me straight?
For the most part, the things you can enter at the GHCi or Hugs prompt are _expressions_. This mostly* excludes _declarations_, which are things like function definitions, datatype declarations, class and instance declarations, etc. Those things need to go into a source file. (*) 'let' expressions will allow you to define local functions as part of an expression, however. GHCi also has a slight variation of 'let' that allows you to define functions for the session.
Is there another tutorial that might be more appropriate for me?
The following tutorial is generally recognized as one of the better ones: http://www.cs.utah.edu/~hal/htut/
I am finding haskell quite appealing. I hope to start writing real (if small) applications to do some data analysis from our Postgres DB. Any hints?
There are several haskell database layers. I've had some luck with HDBC, which has a PostgreSQL driver. http://quux.org:70/devel/hdbc
--George Young -- "Are the gods not just?" "Oh no, child. What would become of us if they were?" (C.S. Lewis)
Rob Dockins Speak softly and drive a Sherman tank. Laugh hard; it's a long way to the bank. -- TMBG