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The field, constructor or member 'fold_left' is not defined.
f#

(I'm a total newbie to F#, just picking up an article on it this morning, so excuse the probably simple question. Google brought no answeres so here's my question!)

A really simple program that reverses a list of numbers 1 to 10 is given here, I copied it from the article:

#light
open System
let reverseNums = list.fold_left (fun a x -> x :: a) [] [1..10]

But, I all I get is the error message "The field, constructor or member 'fold_left' is not defined."

If I type "list." and examine the intellisense, the only things I get are the functions "Cons" and "Equals" and the property "Empty".

I'm making a total newbie error here, aren't I? But what? Do I need to do an 'open' on something else to 'unlock' the extra list functions?

Many thanks!
Rich.

.

Hi,
F# is case sensitive and functions for working with lists are located in a module called "List", so the following will work fine:

1
2
3
4

 
#light
open System
let reverseNums = List.fold_left (fun a x -> x :: a) [] [1..10]

Lowercase "list" is a name of the type, so you can see only static methods there.

(Edit: Corrected the issue - I accidentaly posted it with lowercase "list" too - oops!)

By on 11/3/2008 4:19 AM ()

You mean, of course:

1
2
3
4

 
#light
open System
let reverseNums = List.fold_left (fun a x -> x :: a) [] [1..10]

Yup, this works. Haha, I knew it would be a silly mistake like that. Many thanks! I shall now crawl away and feel slightly embarrassed :-)

By on 11/3/2008 4:30 AM ()

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