dmd -run speed trends

[Witold Baryluk]

On Thursday, 7 December 2023 at 16:32:32 UTC, Witold Baryluk 
wrote:
> dmd


Inspecting output of `dmd -v`, shows that a lot of time is spend 
on various helpers of `writefln`. Changing `writefln` to 
`writeln` (and adjusting things so the output is still the same), 
speeds things a lot:

729.5 ms -> 431.8 ms (dmd 2.106.0)
896.6 ms -> 638.7 (dmd 2.098.1)

Considering that most script like programs will need to do some 
IO, `writefln` looks a little bloated (slow to compile). Having 
string interpolation would probably help a little, but even then 
431 ms is not that great.


Also for completeness, golang:

go1.21.4  121 ms

This is using `go run`.

Way faster.

```go
package main

import (
	"fmt"
	"strings"
)

type Person struct {
	name string
	age  int
}

var people = []Person{
	Person{name: "John", age: 45},
	Person{name: "Kate", age: 30},
}

func oddNumbers(a []int) chan int {
	ch := make(chan int)
	go func() {
		for _, x := range a {
			if x%2 == 0 {
				continue
			}
			ch <- x
		}
		close(ch)
	}()
	return ch
}

func toLookupTable(data string) map[string]bool {
	result := make(map[string]bool)
	for _, w := range strings.Split(data, ";") {
		result[w] = true
	}
	return result
}

func main() {
	for _, person := range people {
		fmt.Printf("%s is %d years old\n", person.name, person.age)
	}

	for odd := range oddNumbers([]int{3, 6, 9, 12, 15, 18}) {
		fmt.Printf("%d\n", odd)
	}

	data := "mov;btc;cli;xor;afoo"
	opcodes := toLookupTable(data)

	for o := range opcodes {
		fmt.Printf("%s\n", o)
	}
}
```