The document introduces COMEFROM, a proposed programming construct that is the opposite of GOTO and allows code execution to jump to arbitrary points. It argues that writing structured code can be difficult and proposes COMEFROM as a solution to make code more readable by eliminating the need to explicitly define control flow. Using COMEFROM, code execution could jump to statements labeled with COMEFROM from any point. The concept is presented partly in jest to challenge conventions of programming language design.

1. COMEFROM
A Humble Programming Construct

2. The Pain
Writing structure code
is hard.

3. Structured Code
● Schemas ?
● Types, WTF ??
● No Monkey Patching ???

4. It gets worse...
● If ? For ? While ?
● Map ? Reduce ? Filter ?
● Try ? Catch ? Except ? Finally ?
● Tail call, what?
● Tons of ways to do the SAME! things
● This is like JavaScript…
● We’re not monkeys !!!
● SERIOUSLY?

5. It gets MUCH worse...
● Object oriented
● Functional?
● Scala?
Real programmers use COBOL or FORTRAN

6. Solution: The goto Statement
Provides automatic, well understood transformations
● Eliminates recursion
● Eliminates unneeded structure
● Offers infinite branching
● Keeps life interesting with fall throughs dead ends

7. But it doesn’t go far
enough
Seriously. Why should you have to tell
your code where to go?

8. 78%of code is clearly readable

9. Let’s change that

10. Introducing COMEFROM
“In computer programming, COMEFROM (or COME FROM)
is an obscure control flow structure used in some
programming languages, originally as a joke. COMEFROM is
roughly the opposite of GOTO in that it can take the execution
state from any arbitrary point in code to a COMEFROM
statement.”

11. Using COMEFROM
func add(a, b int) int {
return a + b
}
comefrom add
func double(a, b *int) {
*a *= 2
*b *= 2
}
// elsewhere in the code.
comefrom add
func triple(a, b *int) {
*a *= 3
*b *= 3

12. “It’s already
here”.

15. Hardware optimizations coming
LCNTR=42;
DO x UNTIL LCE; /* COMEFROM x, unless the loop counter is zero */
F12=F0*F4, F8=F8+F12, F0=dm(I0,M3), F4=pm(I8,M9);
IF NZ dm(I2,M2) = F12;
IF ZF dm(I2,M2) = F1;
x: R2 = R3 + 76; /* the label "x" does not exist in the machine code */

17. EEEW.

18. We all hate
legacy code

19. Let’s use
Python

21. Such
python

22. much
pythonic

23. WOW!