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Left to Right Programming

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Re: Left to Right Programming

#41

Post by layer8 »

Some IDEs provide code templates, where you type some abbreviation that expands into a corresponding code construct with placeholders, followed by having you fill out the placeholders (jumping from one to the next with Tab). The important part here is that the placeholders’ tab order doesn’t need to be from left to right, so in TFA’s example you could have an order like

    {3} for {2} in {1}
which would give you code completion for {3} based on the {1} and {2} that would be filled in first.

There is generally a trade-off between syntax that is nice to read vs. nice to type, and I’m a fan of having nice-to-read syntax out of the box (i.e. not requiring tool support) at the cost of having to use tooling to also make it nice to type.

This is not meant as an argument for the above for-in syntax, but as an argument that left-to-right typing isn’t a strict necessity.

Re: Left to Right Programming

#42

Post by PaulHoule »

chrismorgan wrote: post #9

len(list(filter(lambda line: all([abs(x) >= 1 and abs(x) 0 for x in line]) or all([x This really isn’t fair on Python. Python isn’t very much not designed for this style of functional programming. Plus you haven’t broken lines where you could. Rewrite it as a list comprehension and add line breaks, and turn the inner list comprehensions into generator expressions (`all([…])` → `all(…)`), and change `abs(x) >= 1 and a…

The author's argument is a strong argument against the way Lisp does it, at least for most code, as Lisp tends to put the verb to the left and nouns to the right so your IDE has no idea what nouns you are working with until you've picked the verb.

Re: Left to Right Programming

#43

Post by folkrav »

juancn wrote: post #39

SQL shows it's age by having exactly the same problem. Queries should start by the `FROM` clause, that way which entities are involved can be quickly resolved and a smart editor can aid you in writing a sensible query faster. The order should be FROM -> SELECT -> WHERE, since SELECT commonly gives names to columns, which WHERE will reference. You could even avoid crap like `SELECT * FROM table`, and just write `FROM…

I legitimately never even thought of this, and it feels very obvious in retrospect…

Re: Left to Right Programming

#44

Post by pzmarzly »

juancn wrote: post #39

SQL shows it's age by having exactly the same problem. Queries should start by the `FROM` clause, that way which entities are involved can be quickly resolved and a smart editor can aid you in writing a sensible query faster. The order should be FROM -> SELECT -> WHERE, since SELECT commonly gives names to columns, which WHERE will reference. You could even avoid crap like `SELECT * FROM table`, and just write `FROM…

You may find PRQL interesting. https://prql-lang.org/

Re: Left to Right Programming

#45

Post by layer8 »

juancn wrote: post #39

SQL shows it's age by having exactly the same problem. Queries should start by the `FROM` clause, that way which entities are involved can be quickly resolved and a smart editor can aid you in writing a sensible query faster. The order should be FROM -> SELECT -> WHERE, since SELECT commonly gives names to columns, which WHERE will reference. You could even avoid crap like `SELECT * FROM table`, and just write `FROM…

While I agree, some SQL editors do provide code completion for the SELECT clause if you type the FROM clause first.

Re: Left to Right Programming

#46

Post by astrange »

kmoser wrote: post #5

> Programs should be valid as they are typed. That would be nice if devs always wrote code sequentially, i.e. left to right, one character at a time, one line at a time. But the reality is that we often jump around, filling in some things while leaving other things unfinished until we get back to them. Sometimes I'll write code that operates on a variable, then a minute later go back and declare that variable (perhap…

I agree with this, but it leads to another principle that too many languages violate - it shouldn't fail to compile just because you haven't finished writing it! It should fail in some other non-blocking way.

But some languages just won't let you do that, because they put in errors for missing returns or unused variables.

Re: Left to Right Programming

#47

Post by layer8 »

kmoser wrote: post #5

> Programs should be valid as they are typed. That would be nice if devs always wrote code sequentially, i.e. left to right, one character at a time, one line at a time. But the reality is that we often jump around, filling in some things while leaving other things unfinished until we get back to them. Sometimes I'll write code that operates on a variable, then a minute later go back and declare that variable (perhap…

Also, mutual recursion. ;)

Re: Left to Right Programming

#48

Post by waffletower »

So many engineers define their own narrow ergonomic values and then turn to the interwebs attempting to hammer their myopic belief into others as evangelical truth -- this reads as if the author believes there is a singular left-to-right process that a developer ought to adhere to. The author is oblivious to the non-linear compositional practices of other coders. It would be much more constructive to spend time creating specific tooling to aid your own process and then ask others if the values are also relevant to them. Not every developer embraces LSP, for example, as some are thwarted by its opinionated implementation. Not everyone is willing to give up local structure for auto-complete convenience.

Re: Left to Right Programming

#49

Post by dleeftink »

juancn wrote: post #39

SQL shows it's age by having exactly the same problem. Queries should start by the `FROM` clause, that way which entities are involved can be quickly resolved and a smart editor can aid you in writing a sensible query faster. The order should be FROM -> SELECT -> WHERE, since SELECT commonly gives names to columns, which WHERE will reference. You could even avoid crap like `SELECT * FROM table`, and just write `FROM…

PSQL (and PRQL) use this ordering, and a similar pipe/arrow notation has recently been added to BigQuery.

Check out the DuckDB community extensions:

[0]: https://duckdb.org/community_extensions/extensions/psql.html

[1]: https://duckdb.org/community_extensions/extensions/prql.html

Re: Left to Right Programming

#50

Post by kazinator »

PaulHoule wrote: post #42
chrismorgan wrote: post #9

len(list(filter(lambda line: all([abs(x) >= 1 and abs(x) 0 for x in line]) or all([x This really isn’t fair on Python. Python isn’t very much not designed for this style of functional programming. Plus you haven’t broken lines where you could. Rewrite it as a list comprehension and add line breaks, and turn the inner list comprehensions into generator expressions (`all([…])` → `all(…)`), and change `abs(x) >= 1 and a…

The author's argument is a strong argument against the way Lisp does it, at least for most code, as Lisp tends to put the verb to the left and nouns to the right so your IDE has no idea what nouns you are working with until you've picked the verb.

Pretty much every functional language is verb-initial, as are function calls as well as statements in most mainstream languages.

Verb-final languages like PostScript and Forth are oddballs.

Embedded verbs are a thing of course, with the largest contribution coming from arithmetic expressions with infix operators, followed by certain common syntax like "else" being in the of an "if" statement, followed by things like these Python comprehensions and if syntactic experiments and whatnot.

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