How can I compare string..?

[ghost]

1 import io::;
2 import core::;
3 fn main(){
4 let price;
5
6 let item = io::stdin().read_line();
7
8 if str::eq(item,"salad"){
9 price = 3.5;
10 }else if str::eq(item,"kiwie"){
11 price = 2.25;
12 }else{
13 price = 5.0;
14 }
15
16 io::println(#fmt("%f",price));
17 }

I used to develope with C but there is a function "strcmp" but here. I don't know which I can use comparing the string..

Let me know them how to use.

Also I'd like to know about how to use API document properly. I can find and see the function and some kind of that. But I don't know how to use exactly

[ghost]

I think we can't compare the words which are static or constants.

That's the problem why I can't compare :)

[jdm]

You probably need to compare against ~"unique strings"

[AngryLawyer]

You can use == to compare strings, and as jdm says, you need the tilde in front of the strings

    if item == ~"salad" {
        price = 3.5;
    } else if item == ~"kiwie" {
         price = 2.25;
    } else {
        price = 5.0;
    }

Should make it compile, although I'm working off of the Master branch rather than the 0.3 release (and in mine, I have to cast the result of io::stdin() to io::ReaderUtil to get at read_line()

[graydon]

We're working on a number of bugs in this space; you're sort of stumbling over them all at once, sadly. We hope this will be cleaned up soon. It should not generally be necessary; in the meantime, str::cmp_slice will do what you're after (borrow both strings and compare them).

[nikomatsakis]

I don't understand what the... bug is here, exactly? Is this a dup of #3470?

[nikomatsakis]

No clear bug, far as I know things are working, closing.

[nikomatsakis]

For posterity's sake: the reason that we can't just implement equality for &str and let the compiler handle the rest is that this wouldn't work for cases where you have strings embedded in data structures. For example, imagine comparing (~str, ~str)---in this case, we would match against the types (A, B) where A and B must implement Eq Here A (and B) are ~str, so ~str must implement Eq. This is in generic code so borrowing doesn't apply, since the code in question doesn't know if the value being compared is a ~str (which could be borrowed) or something else.