digitalmars.D.learn - Programming in D by Ali =?UTF-8?B?w4dlaHJlbGk=?=
- vino (19/19) Oct 17 2016 Hi All,
- =?UTF-8?Q?Ali_=c3=87ehreli?= (11/30) Oct 17 2016 What version is your compiler? My version is DMD64 D Compiler v2.072.0-b...
- vino (3/16) Oct 17 2016 Hi Ali,
- cym13 (5/24) Oct 17 2016 I don't see what you don't understand, you said it yourself:
- tcak (2/8) Oct 17 2016 I would expect him to see the first error on `immSlice ~= 3;`.
- vino (16/44) Oct 17 2016 Hi,
- =?UTF-8?Q?Ali_=c3=87ehreli?= (19/64) Oct 18 2016 What is meant in that section in the book is
Hi All,
As per the book named in the subject it states as below,so can
some one guide me what is wrong in the below code nor correct if
my understanding is wrong.
Page 154
immutable(int[]) specifies that neither the slice nor its
elements can be modified.
So which means that a element or a slice of any array can be
modified, but the below example code is not working.
import std.stdio;
void main() {
immutable(int[]) immSlice = [ 1, 2 ];
immSlice ~= 3;
immSlice[0] = 3; // Error's out at this point
immSlice.length = 1;
writeln(immSlice);
}
From,
Vino.B
Oct 17 2016
On 10/17/2016 11:10 AM, vino wrote:
Hi All,
As per the book named in the subject it states as below,so can some one
guide me what is wrong in the below code nor correct if my understanding
is wrong.
Page 154
immutable(int[]) specifies that neither the slice nor its elements can
be modified.
So which means that a element or a slice of any array can be modified,
but the below example code is not working.
import std.stdio;
void main() {
immutable(int[]) immSlice = [ 1, 2 ];
immSlice ~= 3;
immSlice[0] = 3; // Error's out at this point
immSlice.length = 1;
writeln(immSlice);
}
From,
Vino.B
What version is your compiler? My version is DMD64 D Compiler v2.072.0-b2.
Trying the code with a recent compiler produces three compilation errors
for the following three lines
immSlice ~= 3;
immSlice[0] = 3;
immSlice.length = 1;
Error: cannot modify immutable expression immSlice
Error: cannot modify immutable expression immSlice[0]
Error: cannot modify immutable expression immSlice
Ali
Oct 17 2016
vino <vino_ss hotmail.com> On Monday, 17 October 2016 at 18:17:24 UTC, Ali Çehreli wrote:On 10/17/2016 11:10 AM, vino wrote:Hi Ali, I am using DMD64 D Compiler v2.071.2-b5[...]What version is your compiler? My version is DMD64 D Compiler v2.072.0-b2. Trying the code with a recent compiler produces three compilation errors for the following three lines immSlice ~= 3; immSlice[0] = 3; immSlice.length = 1; Error: cannot modify immutable expression immSlice Error: cannot modify immutable expression immSlice[0] Error: cannot modify immutable expression immSlice Ali
Oct 17 2016
On Monday, 17 October 2016 at 18:10:01 UTC, vino wrote:
Hi All,
As per the book named in the subject it states as below,so can
some one guide me what is wrong in the below code nor correct
if my understanding is wrong.
Page 154
immutable(int[]) specifies that neither the slice nor its
elements can be modified.
So which means that a element or a slice of any array can be
modified, but the below example code is not working.
import std.stdio;
void main() {
immutable(int[]) immSlice = [ 1, 2 ];
immSlice ~= 3;
immSlice[0] = 3; // Error's out at this point
immSlice.length = 1;
writeln(immSlice);
}
From,
Vino.B
I don't see what you don't understand, you said it yourself:
"neither the slice nor its elements can be modified". So you
can't modify the elements of an immutable array. immSlice is an
immutable array of which you are trying to modify an element.
Oct 17 2016
On Monday, 17 October 2016 at 18:20:00 UTC, cym13 wrote:On Monday, 17 October 2016 at 18:10:01 UTC, vino wrote:I would expect him to see the first error on `immSlice ~= 3;`.[...]I don't see what you don't understand, you said it yourself: "neither the slice nor its elements can be modified". So you can't modify the elements of an immutable array. immSlice is an immutable array of which you are trying to modify an element.
Oct 17 2016
On Monday, 17 October 2016 at 18:20:00 UTC, cym13 wrote:On Monday, 17 October 2016 at 18:10:01 UTC, vino wrote:Hi, Thank you for your reply, can you address why the below code is not working import std.stdio; void main() { int[] Array = [ 1, 2, 3, 4 ]; immutable(int[]) immSlice = Array[ 0 .. 2 ]; writeln("1st : ", immSlice); immSlice ~= 3; writeln("2nd : ", immSlice); immSlice[0] = 3; writeln("3rd : ", immSlice); immSlice.length = 1; writeln("4th : ",immSlice); }Hi All, As per the book named in the subject it states as below,so can some one guide me what is wrong in the below code nor correct if my understanding is wrong. Page 154 immutable(int[]) specifies that neither the slice nor its elements can be modified. So which means that a element or a slice of any array can be modified, but the below example code is not working. import std.stdio; void main() { immutable(int[]) immSlice = [ 1, 2 ]; immSlice ~= 3; immSlice[0] = 3; // Error's out at this point immSlice.length = 1; writeln(immSlice); } From, Vino.BI don't see what you don't understand, you said it yourself: "neither the slice nor its elements can be modified". So you can't modify the elements of an immutable array. immSlice is an immutable array of which you are trying to modify an element.
Oct 17 2016
On 10/17/2016 11:48 PM, vino wrote:On Monday, 17 October 2016 at 18:20:00 UTC, cym13 wrote:What is meant in that section in the book is 1) We cannot modify elements of an immutable slice 2) We cannot modify an immutable slice (e.g. cannot add elements to it) That's the reason for the following three compilation errors: Error: cannot modify immutable expression immSlice Error: cannot modify immutable expression immSlice[0] Error: cannot modify immutable expression immSlice Your new code has another compilation error here: int[] Array = [ 1, 2, 3, 4 ]; immutable(int[]) immSlice = Array[ 0 .. 2 ]; // <-- ERROR Error: cannot implicitly convert expression (Array[0..2]) of type int[] to immutable(int[]) That's because immSlice wants to guarantee that it has immutable elements. For that to be true, it cannot share elements of a mutable slice. Otherwise, elements could be modified through Array, which would also change immSlice's elements. (Remember that Array and immSlice would be sharing elements.) AliOn Monday, 17 October 2016 at 18:10:01 UTC, vino wrote:Hi, Thank you for your reply, can you address why the below code is not working import std.stdio; void main() { int[] Array = [ 1, 2, 3, 4 ]; immutable(int[]) immSlice = Array[ 0 .. 2 ]; writeln("1st : ", immSlice); immSlice ~= 3; writeln("2nd : ", immSlice); immSlice[0] = 3; writeln("3rd : ", immSlice); immSlice.length = 1; writeln("4th : ",immSlice); }Hi All, As per the book named in the subject it states as below,so can some one guide me what is wrong in the below code nor correct if my understanding is wrong. Page 154 immutable(int[]) specifies that neither the slice nor its elements can be modified. So which means that a element or a slice of any array can be modified, but the below example code is not working. import std.stdio; void main() { immutable(int[]) immSlice = [ 1, 2 ]; immSlice ~= 3; immSlice[0] = 3; // Error's out at this point immSlice.length = 1; writeln(immSlice); } From, Vino.BI don't see what you don't understand, you said it yourself: "neither the slice nor its elements can be modified". So you can't modify the elements of an immutable array. immSlice is an immutable array of which you are trying to modify an element.
Oct 18 2016