What is Parsing?
When you read an expression, like
1/2+3.4, you can immediately understand some of its meaning. You recognize that there are three numbers, and that the numbers are combined with operators. You may also recall that division has higher precedence than addition, so you would divide
1/2 before adding
+3.4 when evaluating the expression.
Early last week, Desmos released a change to the way that basic arithmetic is evaluated in our calculators. The goal of this change is to make the calculators’ answers match people’s intuitions more often by computing numerical answers exactly instead of approximately in more cases where a human would.
In his wildly popular 2015 Bloomberg article about
Paul Ford included a short section about what happens inside your computer
between pressing the “a”
and getting an
a printed to the screen. His point was that even the most
straightfoward human instructions can become surprisingly delicate and complex
when filtered through wire and silicon, and that programmers are basically just
humans with the right constitution to brook the journey.