style_guide.md

Code Style Guide

Consistency is key!

R Style Guide

Main guide: tidyverse style guide

Below are more specific guidelines

Line length

• use 4 spaces (not the tab character and not 2 spaces) to indent
• do not exceed 80 characters per line
  • very helpful to be able to open windows side by side w/o scrolling
  • very helpful to be able to see the code in a terminal window (if needed)
• functions hint: for long lines use this format (which can work with pipes too)

    long_function_name_that_never_ends(
        first_long_argument_name = 1,
        second_long_argument_name = 2,
    )

Comments and documentation

• Always in English, please run a spell-checker
• Explain Why not What (assume people know the programming language)
  • leave a space after the comment symbol, as in #

Naming

• Watch The Naming of Ducks
• Where the language and the previous code base allow, variable names should follow the pattern my_variable (no CamelCase, just use underscore)
  • This works for Python, R and SQL identifiers
• Functions names should be verbs
  • except for math-line functions such as cos()
  • avoid get_ and set_ unless they are OO like methods
  • should fit on one page (if longer, think about creating a second function)
• When using Hungarian notation, consider using the suffixes from purrr::, such as _dbl, _lgl, etc.
  • other suffixes:
    • _msk: mask for logical/selecting within a vector
    • _idx: index, as in var_idx <- which(var_msk)
    • _sp: spatial package
    • _mat: matrix
• Table / collection / list names: singular or plural?
  • good subjective discussion
  • preference for singular
  • use singular for dataframes, SQL tables, ORM classes
  • use plural for vectors, e.g., customer_names