11 Matching Annotations
  1. Aug 2020
    1. Now it is much clearer that id is really a family of infinitely many functions. It is fair to say that it is an abstract function (as opposed to a concrete one), because its type abstracts over the type variable a. The common and proper mathematical wording is that the type is universally quantified (or often just quantified) over a.

      This was very neatly put, and forall above is also spot on.

    1. Quantified Types

      My main issue with this book is that the difficulty is exponentially increasing, and by "keeping it simple" (i.e., trying to use simple terms) it is even harder to do a proper research.

      For example:

      1. The name of this chapter

      This chapter should have been called Explicitly quantified type or Explicit universal quantification as it is too general as is, and doing a search to get to know more when someone has no formal/previous functional programming background, makes very hard.

      Most importantly though, even if Haskell not mentioned, the word "explicit" would have been important.

      It is also more about generic parameters than about quantification itself, and forall is kind of introduced but it is totally misleading.

      2. forall

      The post “forall” is the type-level “lambda” (saved) is the best, most succinct explanation of forall that I ever found. Unfortunately not before going down the rabbit hole.. (See links below.) One still needs to know about

      • typeclasses
      • generic parameters
      • constraints
      • what pragmas are but after that, it is straightforward.

      (Jordan's Reference section on forall also doesn't help much.)

      forall is also mandatory in PureScript (which is also not mentioned when introducing it), and I believe a comparison (the way the above post did) with Haskell is important, but at the right time. At least Jordan's Reference tries to put it off until later, but still before explaining concepts required to understand it.

      3. The "rabbit hole" links

      These are all good resources, but not for uninitiated mortals, and at a lower level (such as where I am now) they raise more questions than answers.

  2. Jul 2020
    1. Formula for Calculating Concentration
    2. There is a simple mathematical relationship between the fraction of droplets that are unoccupied (black bar) and the concentration of target molecules.
  3. Jan 2020
    1. The concentration of GFP in the sample had been measured using a nanodrop and was ~120μM

      How was the protein quantified? I assume UV absorption or Bradford assay was used.

  4. Oct 2017