angelmz
Golang to Elixir code conversion
I’m trying to translate following Go code into Elixir. I’ve also included my own attempt.
package main
import "fmt"
const spanish = "Spanish"
const french = "French"
const englishHelloPrefix = "Hello, "
const spanishHelloPrefix = "Hola, "
const frenchHelloPrefix = "Bonjour, "
// Hello returns a personalised greeting in a given language.
func Hello(name string, language string) string {
if name == "" {
name = "World"
}
return greetingPrefix(language) + name
}
func greetingPrefix(language string) (prefix string) {
switch language {
case french:
prefix = frenchHelloPrefix
case spanish:
prefix = spanishHelloPrefix
default:
prefix = englishHelloPrefix
}
return
}
func main() {
fmt.Println(Hello("world", ""))
}
Below I have my attempt at converting it to Elixir. I just want to make sure it’s the “Elixir way” of doing things. What would you all have done differently?
defmodule Hello do
@english_hello_prefix "Hello, "
@spanish_hello_prefix "Hola, "
@french_hello_prefix "Bonjour, "
# Returns a personalised greeting in a given language.
def hello(name, language) do
name = if name == "" do
"World"
else
name
end
greeting_prefix(language) <> name
end
def greeting_prefix(language) do
case language do
"french" -> @french_hello_prefix
"spanish" -> @spanish_hello_prefix
_ -> @english_hello_prefix
end
end
end
IO.puts Hello.hello("world", "")
Marked As Solved
al2o3cr
None of the below are “rules”, but some thoughts:
- putting single-use constants in a module attribute generates identical bytecode to putting them at the point-of-use and only obscures the function where they are used (especially if the attributes are kept at the top of the file while the use site is many lines below). Here’s an alternative
greeting_prefix:
def greeting_prefix(language) do
case language do
"french" -> "Bonjour, "
"spanish" -> "Hola, "
_ -> "Hello, "
end
end
-
another common style of writing a function with a single simple (no computation in the
case ... do)casestatement as the body is with pattern-matching like in @D4no0’s version -
IMO it can be clearer to keep the parts of a function at the same “level of detail”; in this case the
namecomputation and thegreeting_prefixcomputation are both used inhellobut thenamepart has the control structure exposed. Consider making the function more symmetric:
def hello(name, language) do
greeting_prefix(language) <> name_with_default(name)
end
defp name_with_default(""), do: "World"
defp name_with_default(name), do: name
- finally, if you find yourself regularly writing
casestatements against strings, consider making the possible values more explicit by converting to known atoms at a boundary. For instance, you might change the caller ofhelloto instead pass one of:english,:french, or:spanishand then match exhaustively:
def greeting_prefix(language) do
case language do
:french -> "Bonjour, "
:spanish -> "Hola, "
:english -> "Hello, "
end
end
Also Liked
D4no0
Your solution is perfectly viable with the exception if name == "" do statement, since elixir is dynamically typed. If you want to check for empty string, you have to ensure that the parameter is string, you can use a guard for this:
def hello(name, language) when is_binary(name) do
name = if name == "" do
"World"
else
name
end
greeting_prefix(language) <> name
end
As for a different approach, you could do the same with:
defmodule Hello do
@english_hello_prefix "Hello, "
@spanish_hello_prefix "Hola, "
@french_hello_prefix "Bonjour, "
def greeting_prefix("french"), do: @french_hello_prefix
def greeting_prefix("spanish"), do: @spanish_hello_prefix
def greeitng_prefix(_unknown), do: @english_hello_prefix
def hello(name, language) when byte_size(name) > 0, do: greeting_prefix(language) <> name
def hello(name, language), do: greeting_prefix(language) <> "World"
end
Popular in Questions
Other popular topics
Latest on Elixir Forum
Sponsor Spotlight
Build Elixir applications with speed and confidence.
Categories:
Sub Categories:
Forums
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Practical resources that improve the lives of professional developers.
Producing high quality Elixir screencasts since 2017.
Enabling companies to succeed by building software people love.
Courses that'll move you from confusion to "Aha, now I get it!"