utexas CS 378, Symbolic Programming
Symbolic Programming
Symbols are words that refer to, or denote, other things: their referents:
- Variable names in programming languages
- Variables in equations
- English words
Symbolic Programming manipulates stuctures of symbols, typically represented as trees:
-
solve equations
-
translate a program to another language
-
specialize a generic program
-
convert units of measurement
-
translate English into a database query
-
compose program components
Functional Programming
A functional program is one with no side effects:
- changing a global variable
- updating a database
- printing
If we call sin(x)
, it will just return a value, but will have no side effects.
Functional programming does everything by composition of functions:
guacamole:
season(mash(slice(peel(wash(avocado)))))
Functions are composed so that the output of one function is the input of the next function(pipelined). Functional programming works well with distributed cloud computing: the function can be replicated on many servers and executed in parallel on massive amounts of data.