Can we put some operators at the beginning of lines?

[DavisVaughan]

There is a very popular issue in prettier about putting the operators of multiline binary expressions at the beginning of lines
prettier/prettier#3806

Lots of languages do prefer operators at the beginning, as it improves readability:
prettier/prettier#3806 (comment)

It also has the same benefits of trailing commas, you can often rearrange multiline conditions with a simple copy paste if the operator is leading:

# Start here
this_thing
  && that_thing
  && this_other_thing

# Decide this_other_thing should go second, simple copy paste of the whole line
this_thing
  && this_other_thing
  && that_thing

# Compared to
this_thing && 
  that_thing && 
  this_other_thing

# Changing to this, which is not a simple copy paste of full lines
this_thing && 
  this_other_thing && 
  that_thing

I tend to agree with the readability argument (the trailing comma argument is less convincing to me), the pep style guide has a good motivating example:
https://peps.python.org/pep-0008/#should-a-line-break-before-or-after-a-binary-operator

# Wrong:
# operators sit far away from their operands
income = (gross_wages +
          taxable_interest +
          (dividends - qualified_dividends) -
          ira_deduction -
          student_loan_interest)

# Correct:
# easy to match operators with operands
income = (gross_wages
          + taxable_interest
          + (dividends - qualified_dividends)
          - ira_deduction
          - student_loan_interest)

This might be a bit tricky for R code (and maybe for Python?) because at top level or inside { this is invalid R code without being wrapped in () (like in the Python example):

# Invalid R code at top level
income <- gross_wages
          + taxable_interest
          + (dividends - qualified_dividends)
          - ira_deduction
          - student_loan_interest

# This works
income <- (gross_wages
          + taxable_interest
          + (dividends - qualified_dividends)
          - ira_deduction
          - student_loan_interest)

It's somewhat common to see this kind of thing in if statements (though I'd argue you should create a simpler condition...)

if (
  this_thing
    && that_thing
    && this_other_thing
) {
  body
}

We'd also have to consider pipelines, which are also sequences of binary operators. It's mostly easy with %>% and |>, they just never split this way. But with +? That's tricky because it could be a ggplot2 sequence or just a sequence of arithmetic operations!

# `+` is always trailing here, not leading.
ggplot(data) +
  geom_line() +
  geom_bar()

[DavisVaughan]

We mostly think this is probably too complicated, and it would be confusing to end up with mixed styles of leading and trailing operators since we can't always make them leading due to restrictions in R (being an interpreted language)