Odin/examples/basic.odin

#load "runtime.odin"
#load "win32.odin"
#load "file.odin"

print_string :: proc(s: string) {
	file_write(file_get_standard(FileStandard.OUTPUT), s as []byte)
}

byte_reverse :: proc(b: []byte) {
	n := len(b)
	for i := 0; i < n/2; i++ {
		b[i], b[n-1-i] = b[n-1-i], b[i]
	}
}

encode_rune :: proc(r: rune) -> ([4]byte, int) {
	buf: [4]byte
	i := r as u32
	mask: byte : 0x3f
	if i <= 1<<7-1 {
		buf[0] = r as byte
		return buf, 1
	}
	if i <= 1<<11-1 {
		buf[0] = 0xc0 | (r>>6) as byte
		buf[1] = 0x80 | (r)    as byte & mask
		return buf, 2
	}

	// Invalid or Surrogate range
	if i > 0x0010ffff ||
	   (i >= 0xd800 && i <= 0xdfff) {
		r = 0xfffd
	}

	if i <= 1<<16-1 {
		buf[0] = 0xe0 | (r>>12) as byte
		buf[1] = 0x80 | (r>>6)  as byte & mask
		buf[2] = 0x80 | (r)     as byte & mask
		return buf, 3
	}

	buf[0] = 0xf0 | (r>>18) as byte
	buf[1] = 0x80 | (r>>12) as byte & mask
	buf[2] = 0x80 | (r>>6)  as byte & mask
	buf[3] = 0x80 | (r)     as byte & mask
	return buf, 4
}

print_rune :: proc(r: rune) {
	buf, n := encode_rune(r)
	str := buf[:n] as string
	print_string(str)
}

print_space :: proc() { print_rune(#rune " ") }
print_nl    :: proc() { print_rune(#rune "\n") }

print_int :: proc(i: int) {
	print_int_base(i, 10);
}
print_int_base :: proc(i, base: int) {
	NUM_TO_CHAR_TABLE :: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz@$"

	buf: [65]byte
	len := 0
	negative := false
	if i < 0 {
		negative = true
		i = -i
	}
	if i == 0 {
		buf[len] = #rune "0"
		len++
	}
	for i > 0 {
		buf[len] = NUM_TO_CHAR_TABLE[i % base]
		len++;
		i /= base
	}

	if negative {
		buf[len] = #rune "-"
		len++
	}

	byte_reverse(buf[:len])
	print_string(buf[:len] as string)
}

print_uint :: proc(i: uint) {
	print__uint(i, 10, 0, #rune " ")
}
print__uint :: proc(i, base: uint, min_width: int, pad_char: byte) {
	NUM_TO_CHAR_TABLE :: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz@$"

	buf: [65]byte
	len := 0
	if i == 0 {
		buf[len] = #rune "0"
		len++
	}
	for i > 0 {
		buf[len] = NUM_TO_CHAR_TABLE[i % base]
		len++
		i /= base
	}
	for len < min_width {
		buf[len] = pad_char
		len++
	}

	byte_reverse(buf[:len])
	print_string(buf[:len] as string)
}

print_bool :: proc(b : bool) {
	if b { print_string("true") }
	else { print_string("false") }
}

print_pointer :: proc(p: rawptr) #inline { print__uint(p as uint, 16, 0, #rune " ") }

print_f32     :: proc(f: f32) #inline { print__f64(f as f64, 7) }
print_f64     :: proc(f: f64) #inline { print__f64(f, 10) }

print__f64 :: proc(f: f64, decimal_places: int) {
	if f == 0 {
		print_rune(#rune "0")
		return
	}
	if f < 0 {
		print_rune(#rune "-")
		f = -f
	}

	print_u64 :: proc(i: u64) {
		NUM_TO_CHAR_TABLE :: "0123456789"

		buf: [22]byte
		len := 0
		if i == 0 {
			buf[len] = #rune "0"
			len++
		}
		for i > 0 {
			buf[len] = NUM_TO_CHAR_TABLE[i % 10]
			len++
			i /= 10
		}
		byte_reverse(buf[:len])
		print_string(buf[:len] as string)
	}

	i := f as u64
	print_u64(i)
	f -= i as f64

	print_rune(#rune ".")

	mult := 10.0
	for decimal_places := 6; decimal_places >= 0; decimal_places-- {
		i = (f * mult) as u64
		print_u64(i as u64)
		f -= i as f64 / mult
		mult *= 10
	}
}