The OFFICIAL programming thread

Blanks

@hog said in The OFFICIAL programming thread:

Oh, and:

Maybe you should program this forum. That’s award winning content right there.

@rote7 said in The OFFICIAL programming thread:

@hog said in The OFFICIAL programming thread:

const BITS_PER_DIMENSION = 2
const MAX_EXTENT = 1 << (BITS_PER_DIMENSION - 1)

func _ready():
	print("Bits per dimension: %d, Max extent: %d" % [BITS_PER_DIMENSION, MAX_EXTENT])
	var ids = []
	for col in range(-MAX_EXTENT, MAX_EXTENT):
		var col_normalized = col + MAX_EXTENT
		var col_shifted = col_normalized << BITS_PER_DIMENSION
		for row in range(-MAX_EXTENT, MAX_EXTENT):
			var row_normalized = row + MAX_EXTENT
			var id = col_shifted + row_normalized
			ids.push_back(id)
			print("col: %4d, row: %4d, id: %4d" % [col, row, id])
	
	print("**************** Reversed **************")
        var mask_high = (1 << BITS_PER_DIMENSION) - 1
	print("mask high: %d" % mask_high)
	for id in ids:
		var row_normalized = id & mask_high
		var row = row_normalized - MAX_EXTENT
		var col_normalized = id >> BITS_PER_DIMENSION
		var col = col_normalized - MAX_EXTENT
		print("col: %4d, row: %4d, id: %4d" % [col, row, id])

Result:

--- Debugging process started ---
Godot Engine v3.3.2.stable.official - https://godotengine.org
OpenGL ES 2.0 Renderer: GeForce 940MX/PCIe/SSE2
OpenGL ES Batching: ON
 
Bits per dimension: 2, Max extent: 2
col:   -2, row:   -2, id:    0
col:   -2, row:   -1, id:    1
col:   -2, row:    0, id:    2
col:   -2, row:    1, id:    3
col:   -1, row:   -2, id:    4
col:   -1, row:   -1, id:    5
col:   -1, row:    0, id:    6
col:   -1, row:    1, id:    7
col:    0, row:   -2, id:    8
col:    0, row:   -1, id:    9
col:    0, row:    0, id:   10
col:    0, row:    1, id:   11
col:    1, row:   -2, id:   12
col:    1, row:   -1, id:   13
col:    1, row:    0, id:   14
col:    1, row:    1, id:   15
**************** Reversed **************
mask high: 3
col:   -2, row:   -2, id:    0
col:   -2, row:   -1, id:    1
col:   -2, row:    0, id:    2
col:   -2, row:    1, id:    3
col:   -1, row:   -2, id:    4
col:   -1, row:   -1, id:    5
col:   -1, row:    0, id:    6
col:   -1, row:    1, id:    7
col:    0, row:   -2, id:    8
col:    0, row:   -1, id:    9
col:    0, row:    0, id:   10
col:    0, row:    1, id:   11
col:    1, row:   -2, id:   12
col:    1, row:   -1, id:   13
col:    1, row:    0, id:   14
col:    1, row:    1, id:   15

My bit shifting days are but a remote memory so you may have to help me understand how

var id = col_shifted + row_normalized

does not overwrite the previously stored pattern in col_shifted.

Sure, it’s a combination of three things:

they’ve both been converted to unsigned ints (normalized) so the highest bit isn’t set in either number
and the lowest bits of col_shifted are 0 because of the shift
row_normalized only has the lowest bits set because the size of the number is constrained to +/- MAX_EXTENTS

So, even with maximum values for row and column, the addition is like:

00001100 col_shifted +
00000011 row_normalized =
--------
00001111

Edit: by the way, the code i posted earlier was just a proof of concept. My actual use case (which I’ve since coded) has three dimensions. It is using 22 bits (9 + 9 + 4) for a map of 512x512x16 possible locations.

This post is deleted!

Pakoon

tigger

@pakoon said in The OFFICIAL programming thread:

Jajajaja!

rote7

Time for my favorite frownie: m(

rote7

The Case Against SQL - Slashdot

Long-time Slashdot reader RoccamOccam shares "an interesting take on SQL and its issues from Jamie Brandon (who describes himself as an independent researcher who's built database engines, query planners, compilers, developer tools and interfaces). It's title? "Against SQL." The relational model...

Interesting article, I didn’t know that

“The SQL spec (part 2 = 1732) pages is more than twice the length of the Javascript 2021 spec (879 pages), almost matches the C++ 2020 spec (1853) pages and contains 411 occurrences of ‘implementation-defined’, occurrences which include type inference and error propagation.”

Sweet jesus, double the length of the JS specs…

One SQL problem that I couldn’t solve so far is finding a good way to use the output of a single column query (multiple rows, result count must be flexible) as headers and/or fields for a subsequent query.

Kilemall

@rote7 said in The OFFICIAL programming thread:

The Case Against SQL - Slashdot

Long-time Slashdot reader RoccamOccam shares "an interesting take on SQL and its issues from Jamie Brandon (who describes himself as an independent researcher who's built database engines, query planners, compilers, developer tools and interfaces). It's title? "Against SQL." The relational model...

Interesting article, I didn’t know that

“The SQL spec (part 2 = 1732) pages is more than twice the length of the Javascript 2021 spec (879 pages), almost matches the C++ 2020 spec (1853) pages and contains 411 occurrences of ‘implementation-defined’, occurrences which include type inference and error propagation.”

Sweet jesus, double the length of the JS specs…

One SQL problem that I couldn’t solve so far is finding a good way to use the output of a single column query (multiple rows, result count must be flexible) as headers and/or fields for a subsequent query.

Dynamic DB-driven filter query? Sounds like a specific SQL client function to me.

rote7

@Kilemall Yes, that was my first idea too. My goal is to replace a whole lot of client logic with a set of queries/subqueries and/or joins. I am looking for a pivot mechanism to transform a set of column(s) into rows.

E.g. turn

col_1 | col_2
param_1 | value_1
param_2 | value_2
param_foo | value_fo

into a dynamic DB operation that delivers a result like the client generated query “SELECT * FROM table WHERE param_1 = value_1 AND param_2 = value_2 AND param_foo = value_foo” without all the string concatenation, input scrubbing etc. pp. going on in the client.

Gators1

@rote7 said in The OFFICIAL programming thread:

The Case Against SQL - Slashdot

Long-time Slashdot reader RoccamOccam shares "an interesting take on SQL and its issues from Jamie Brandon (who describes himself as an independent researcher who's built database engines, query planners, compilers, developer tools and interfaces). It's title? "Against SQL." The relational model...

Interesting article, I didn’t know that

“The SQL spec (part 2 = 1732) pages is more than twice the length of the Javascript 2021 spec (879 pages), almost matches the C++ 2020 spec (1853) pages and contains 411 occurrences of ‘implementation-defined’, occurrences which include type inference and error propagation.”

Sweet jesus, double the length of the JS specs…

One SQL problem that I couldn’t solve so far is finding a good way to use the output of a single column query (multiple rows, result count must be flexible) as headers and/or fields for a subsequent query.

I think you need to do it as a stored procedure if I remember right and using the PIVOT function. Basically instead of defining the static columns as in the base function, you dynamically insert them in the stored procedure. If you are doing this as part of another code project, you could do the same by just assembling the text of the SQL script to sent dynamically (e.g. “SELECT “& [column name varIable]&” FROM TABLE_NAME;”

Gustaf

This thread:

tenor (18).gif

rote7

@Gators1

Stored procedures are one possible solution. But, and this is a big but, they are DB dependent and I am looking for a way to achieve this with as little as possible DB specific SQL dialect.

As for the client generated SQL, that’s the current solution as a part of a homegrown ORM. I am just curious if it can be done purely in the DB as a way to replace a bunch of DB specific logic during the SQL generation in that ORM.

@Gustaf

/* insert snappy comment here */

I’d snap one off in her

Gators1

@rote7 said in The OFFICIAL programming thread:

@Gators1

Stored procedures are one possible solution. But, and this is a big but, they are DB dependent and I am looking for a way to achieve this with as little as possible DB specific SQL dialect.

As for the client generated SQL, that’s the current solution as a part of a homegrown ORM. I am just curious if it can be done purely in the DB as a way to replace a bunch of DB specific logic during the SQL generation in that ORM.

@Gustaf

/* insert snappy comment here */

@rote7
Yeah, I couldn’t find a way other than a stored procedure in Oracle. The function requires you to define the columns in the SQL so it’s static. Nothing in many searches I did changed that, though the procedure thing was suggested. Seems like a stupid design since pivoting often requires dynamic results.

@Gustaf

Tazz

@gators1 She bumped her chin on something.

Kilemall

@gustaf said in The OFFICIAL programming thread:

This thread:

This is what I was waiting for, the caterwauls of the computer illiterati! SUCCESS ROTE SUCCESS!

Kilemall

@rote7 said in The OFFICIAL programming thread:

@Gators1

Stored procedures are one possible solution. But, and this is a big but, they are DB dependent and I am looking for a way to achieve this with as little as possible DB specific SQL dialect.

As for the client generated SQL, that’s the current solution as a part of a homegrown ORM. I am just curious if it can be done purely in the DB as a way to replace a bunch of DB specific logic during the SQL generation in that ORM.

Suspected as much.

Do Dark Magic, pay with your soul. You know the rules.

Lithu

SELL! SELL! SELL!

The end of open source?

Several weeks ago, the Linux community was rocked by the disturbing news that University of Minnesota researchers had developed (but, as it turned out, not fully executed) a method for introducing what they called "hypocrite commits" to the Linux kernel -- the idea being to distribute hard-to...

tigger

@lithu said in The OFFICIAL programming thread:

SELL! SELL! SELL!

The end of open source?

Several weeks ago, the Linux community was rocked by the disturbing news that University of Minnesota researchers had developed (but, as it turned out, not fully executed) a method for introducing what they called "hypocrite commits" to the Linux kernel -- the idea being to distribute hard-to...

Yahoo news.

Mildly interesting article but the title is possibly the worst click bait I’ve ever seen.