如何在多个源文件中解析导入语句？

Question

I've been trying to find an answer to this question without success.

The question is about import statements in Go when a package consists of multiple source files.

Let's say I have a package called math which consists of multiple files:

|-- math
   |-- add.go
   |-- subtract.go
   |-- divide.go
   |-- multiply.go

Let's assume that the math package makes use of the fmt package therefore it needs the appropriate import statement. But since we have four separate files, we have to import the fmt package multiple times (at least to my understanding):

// add.go
import "fmt"

// subtract.go
import "fmt"

// divide.go
import "fmt"

// multiply.go
import "fmt"

Now the question is, what happens when the package is compiled? Are the statements simply merged together?

If so, why do we have to import the package multiple times (once per each file) and not just have a single file with all the import statements so as to not repeat ourselves?

Answer 1

The specification says:

The scope of the package name of an imported package is the file block of the file containing the import declaration.

Because imports do not have package scope, imports are not merged together and are required in each file that uses the import.

The scoping for imports is unrelated to how the compiler and linker load imported packages. These tools are smart enough to load any given package once.