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Julian Hyde

Julian Hyde

@julianhyde.bsky.social

520 followers 67 following 240 posts

On a mission to tame data. (Ex-Google, always ASF, working on something new.)

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Julian Hyde @julianhyde.bsky.social · 4d

Morel is now in Rust! I just made the first release of the new Rust toolchain for Morel. Morel-Rust implements same language as Morel-Java. It's early days, but potentially performance will be much better.

blog.hydromatic.net/2025/10/23/m...

Morel Rust

Julian Hyde @julianhyde.bsky.social · Jun 22

Thanks - I'll give that a read. Morel's terminal "compute" step is intended provide monoid comprehensions. And the "into" step does something similar. github.com/hydromatic/m...

Add syntax for monoid comprehensions · Issue #69 · hydromatic/morel

Today a from ... group ... [compute ...] query returns a list. If the group key is empty (i.e. group is immediately followed by compute, or group marks the end of the from expression) then the list...

Julian Hyde @julianhyde.bsky.social · Jun 22

I think I have found a way to remove aggregate functions from Morel. They become ordinary functions applied to the collection of elements gathered by the "group" operator (or a query on those elements if you want to pre-filter). github.com/hydromatic/m...

Syntax for aggregate functions · hydromatic morel · Discussion #292

In SQL, aggregate functions are not even functions. A function takes an argument and returns a result, and SQL's aggregate functions are applied to a collection that is implicitly created for each ...

Julian Hyde @julianhyde.bsky.social · Jun 21

How we simplified the syntax of Morel's "order" step blog.hydromatic.net/2025/06/20/s...

Sorting on expressions

Morel’s design philosophy of “everything is an expression” has transformed how we think about queries, making them more composable and flexible than traditional SQL. One stubborn holdout was the order...

blog.hydromatic.net

Julian Hyde @julianhyde.bsky.social · Jun 19

Tragedy of the commons

Julian Hyde @julianhyde.bsky.social · Jun 9

I'm pleased to announce release 0.7 of Morel! This is a huge release, adding support for ordered/unordered data, set operators, and revised order syntax. A major rework of Morel's type inference algorithm delivered function overloading. blog.hydromatic.net/2025/06/08/m...

Morel release 0.7.0

I am pleased to announce Morel release 0.7.0, just one month after release 0.6.0.

blog.hydromatic.net

Julian Hyde @julianhyde.bsky.social · Jun 8

Java doesn't let parameters of lambdas overshadow local variables, but it does let them overshadow fields. I don't think the rule against overshadowing has ever helped me.

Julian Hyde @julianhyde.bsky.social · Jun 8

Thank you! I don’t really want to innovate in type theory, so followed the Wadler/Wehr/Odersky paper as closely as I could. But the result is good - you can write a query with a mixture of bags and lists, no type annotations, and it comes up with the right type.

Julian Hyde @julianhyde.bsky.social · Jun 7

We might both be right. Cocker is a great writer; Shatner is a great performer.

Julian Hyde @julianhyde.bsky.social · Jun 7

I have no idea whether it's fast. I assume you are competing with people who have sweated many weekends to squeeze out performance gains.

But the name 'dijkstralog' is definitely a keeper.

Julian Hyde @julianhyde.bsky.social · Jun 7

I guess some people are still buying Buicks and so Buicks get the modern tech, like adaptive cruise control, only five years after everyone else.

Julian Hyde @julianhyde.bsky.social · Jun 7

Not sure about that. I’ve seen Star Trek but never heard that cover.

Bigger question: will Jarvis Cocker be up there with the great English humorists, Oscar Wilde, Jake Thackray, Flanders & Swann?

Julian Hyde @julianhyde.bsky.social · Jun 7

It is telling that neovim started it for you. In the nineties, Windows nearly wiped out real operating systems, and notepad was the gateway drug. People loved double-clicking files to open them, but without the command line, lost their place in the universe.

Julian Hyde @julianhyde.bsky.social · Jun 7

Database tables are unordered, but functional programming languages work best over ordered lists. Which should Morel prefer? Both! We now have "list" and "bag" types, and full relational algebra over both. blog.hydromatic.net/2025/06/06/o...

Ordered and unordered data

Despite what the relational model says, some data is ordered.

blog.hydromatic.net

Julian Hyde @julianhyde.bsky.social · Jun 4

Be honest, did you ever find a real-world use for SQL's "INTERSECT ALL" operator? Now we did! This post explains how you can use Morel's "intersect" to compute GCD (greatest common divisor). blog.hydromatic.net/2025/06/03/i...

INTERSECT ALL, EXCEPT ALL, and the arithmetic of fractions

SQL’s INTERSECT ALL and EXCEPT ALL operators rarely get attention, but they elegantly solve a classic math problem. The problem is computing the greatest common divisor (GCD) and least common multiple...

blog.hydromatic.net

Julian Hyde @julianhyde.bsky.social · Jun 3

Am I the only one who uses this git trick? To split a commit (in this case a8aee880), include it twice in the rebase script with a b (break) step in the middle. When rebase pauses, revert the parts of the commit that you don't want. They will be applied in the next commit.

Julian Hyde @julianhyde.bsky.social · Jun 3

Is it possible to do serious programming (such as solving Wordle) in a query language? If not, what's missing? The video of my DataCouncil talk is posted. www.youtube.com/watch?v=xwFs...

More Than Query Future Directions of Query Languages, from SQL to Morel

YouTube video by Data Council

www.youtube.com

Julian Hyde @julianhyde.bsky.social · May 22

OK, I merged ordered/unordered queries. Next, an "unorder" step and an "ordinal" expression, so that you can more easily convert between lists and bags.

Julian Hyde @julianhyde.bsky.social · May 21

I'm getting ready to merge a big new feature to Morel - ability to query unordered data sets (bags, and database tables), ordered data sets (lists), and hybrid queries that mix the two. I'd appreciate feedback on whether the specification is clear. github.com/hydromatic/m...

Ordered and unordered queries · Issue #273 · hydromatic/morel

In SQL, tables are inherently unordered, and query results remain unordered until explicitly sorted with an ORDER BY clause. In contrast, functional programming languages like Standard ML -- and by...

Julian Hyde @julianhyde.bsky.social · May 21

I'm getting ready to merge a big new feature to Morel - ability to query unordered data sets (bags, and database tables), ordered data sets (lists), and hybrid queries that mix the two. I'd appreciate feedback on whether the specification is clear. github.com/hydromatic/m...

Ordered and unordered queries · Issue #273 · hydromatic/morel

In SQL, tables are inherently unordered, and query results remain unordered until explicitly sorted with an ORDER BY clause. In contrast, functional programming languages like Standard ML -- and by...

Julian Hyde @julianhyde.bsky.social · May 19

I started a discussion about supporting SQL Pipe syntax in
Apache Calcite. Please chime in. lists.apache.org/thread/1ggd3...

lists.apache.org

Julian Hyde @julianhyde.bsky.social · May 19

Yes, it is.

Julian Hyde @julianhyde.bsky.social · May 18

I feel the same way as you. But I guess when I visit other people’s houses I realize that their definitions of “tidy” and “comfortable” are different from mine. Abstraction is ick to a lot of people.

Julian Hyde @julianhyde.bsky.social · May 18

The other fascinating thing about spreadsheets is that the code is embedded in the data. You start off with pure data and can gradually add little bits of code.

Copying the code involves also copying the data. To apply the same code to a different data set, some kind of abstraction is required.

Julian Hyde @julianhyde.bsky.social · May 18

I wonder whether spreadsheets are attractive to non-programmers because they don't require abstraction. Abstraction is possible (the scripts and functions you mention) but is not the norm.

Julian Hyde @julianhyde.bsky.social · May 18

Spreadsheets are the one and only “language” that lets users solve their problems without hiring or “becoming” programmers. Since then the software folks have been trying (with limited success) to figure out how to make programming languages more like spreadsheets.