Creating a byte fragment with a known text string in the Golang

Question

I have this text that I would like to add to a byte fragment:

s := "There are these two young fish swimming along and they happen to meet an older fish swimming the other way" 

If i write

 b := []byte("There are these two young fish swimming along and they happen to meet an older fish swimming the other way") 

As I understand it, at runtime it will be:

• create a string with values ​​in memory
• create byte fragment
• copy the contents of the string to a byte slice (redistributing if necessary)

I could convert each of the string values ​​to their ASCII equivalent and directly create a byte slice:

 b := []byte{84, 104, ... } 

although it is not very readable.

I understand that the example here is a little trivial, and most computers can do this instantly, but I'm interested. Does the compiler interpret []byte("blah") and turn it into an efficient byte fragment at compile time? Would a better solution change if the string contains non-ASCII characters?

Answer 1

Go inserts a string into an executable program as a string literal. It converts a string literal to a byte slice at runtime using the runtime.stringtoslicebyte function.

Answer 2

If you initialize the variable []byte from a constant string, it seems that the compiler is smart enough not to create an intermediate string: instead, the substitution array for the byte segment is initialized directly from the static data, and not to construct the string variable first.

There is a copy of the data, but this should be expected when creating a mutable type.