EIP-969: style corrections + syntax HLing + make C-code blob a drop-in snippet.

[veox]

Mostly removes trailing whitespace and adds hyphens.

---

EDIT: Now also edits the C snippet to be an actual program that can be compiled.

[veox]

The C-code blob fails to compile for me.

Other than type names being slightly different in my gcc (7.3.1), this line:

 uint32_t result = (uint_32)(candidate * fnv_candidate);

Has (uint_32), which is not a recognised type.

Also, the loop shown in current master HEAD 9fba86e5 is endless. X_X

---

This compiles (and has the infinite-loop fixed):

// http://eips.ethereum.org/EIPS/eip-969

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int main() {
    u_int32_t candidate = 0;
    u_int32_t dups = 0;
    u_int32_t fnv_candidate = 0x10001a7; // MODIFY!
    u_int8_t *counts = malloc(0xFFFFFFFF);

    memset(counts, '\0', 0xFFFFFFFF);

    for (candidate = 0; candidate < 0xFFFFFFFF; candidate++) {
        u_int32_t result = (u_int32_t)(candidate * fnv_candidate);
        u_int8_t oldCount = counts[result];

        counts[result] = counts[result]+1;
        if (oldCount != 0) {
            dups++;
        }

        //// progress display: remove comment to speed down
        //if ((candidate & 0xFFFFF) == 0xFFFFF) printf("0x%08x\n", candidate);
    }
    printf("\nFNV candidate 0x%08x : %i dups\n", fnv_candidate, dups);

    return 0;
}

It gives a result of "0 dups". Expected?.. No?..

[veox]

To clarify: I'm trying to run the code provided, since

It can be empirically confirmed that no more than 1 duplicates occur in the 32 bit word space with these constants.

suggests empirical confirmation, yet contains a typo: either "no more than 1??? duplicates occur", or "no more than 1 duplicate occurs".

---

EDIT: My understanding of the code above suggests the latter.

[eip-automerger]

Hi! I'm a bot, and I wanted to automerge your PR, but couldn't because of the following issue(s):

• EIP 969 requires approval from one of (@AirSquirrels)

[veox]

Should I add the changes outlined above to this PR, or open a new one?..

[AirSquirrels]

Yes sorry I retyped the EIP originally as pseudo code for clarity (my original was a bit messy, iterating through a larger number of constants) in the EIP, but ended up being close to complete C code. The mechanism is the same. Note the constant is also written for only one of the FNV constant, each should be evaluated

[veox]

OK.

I've incorporated the changes you've made in the interim (github's merge-master strategy happily wiped them instead of warning of incompatibility); and put the C program in as a copy-paste snippet.

It doesn't loop through the proposed constants, in order to keep the snippet short. It'd maybe make sense to read those from stdin.

[veox]

@AirSquirrels As I understand, as the EIP's champion, you can merge this PR. No one else is going to assume duty to do so.

If you find the changes acceptable, please do so. If not, and there's some unaddressed concern you have, please voice it. :)

[AirSquirrels]

@veox I approve of these changes, however I am not well versed in the processes here for giving my approval to the eip-automerger. I do not have permissions to merge into the main repo.

[Arachnid]

@AirSquirrels Click on "Files Changed", then "Review Changes", click the "Approve" radio box, and submit.

[AirSquirrels]

@Arachnid Thanks, I see that now.