transducer

Let's start with a definition: A transducer is a function that takes a reducer function and returns a reducer function. A reducer is a binary function that takes an accumulator and a value and returns an accumulator. A reducer can be executed with a reduce function (note: all function are curried but I've cat out this as well as definitions for pipe and compose for the sake of readability - you can see them in live demo ): const reduce = (reducer, init, data) => { let result = init; for (const item of data) { result = reducer(result, item); } return result; } With reduce we can implement map

Can someone please tell me what a finite state transducer is? I have read the Wikipedia article and don't understand a thing. A finite state transducer (FST) is a finite state automaton (FSA, FA) which produces output as well as reading input, which means it is useful for parsing (while a "bare" FSA can only be used for recognizing, i.e. pattern matching). An FST consists of a finite number of states which are linked by transitions labeled with an input/output pair. The FST starts out in a designated start state and jumps to different states depending on the input, while producing output

In my previous Quesion: Extracting data from a function chain without arrays @Aadit M Shah gave me astonishing solution as follows: https://stackoverflow.com/a/51420884/6440264 Given an expression like A(a)(b)(f) where f is a function, it's impossible to know whether f is supposed to be added to the list or whether it's the reducing function. Hence, I'm going to describe how to write expressions like A(a)(b)(f, x) which is equivalent to [a, b].reduce(f, x) . This allows us to distinguish when the list ends depending upon how many arguments you provide: const L = g => function (x, a) { switch

In this blog entry, "CSP and transducers in JavaScript" , the author states: First, we have to realise that many array (or other collection) operations like map , filter and reverse can be defined in terms of a reduce . So then we see a number of implementations of this in Clojure aren't lazy, they are eager: user> (defn eager-map [f coll] (reduce (fn [acc v] (conj acc (f v))) [] coll)) #'user/eager-map user> (eager-map inc (range 10)) [1 2 3 4 5 6 7 8 9 10] My question is, are Clojure transducers eager? Beyamor Transducers are very simple functions - they don't have a notion of laziness or,

A nondeterministic automaton can be simulated easily on an input string by just keeping track of the states the automaton is in, and how far in the input string it has gotten. But how can a nondeterministic transducer (a transducer, of course, can translate input symbols to output symbols, and give as output a string, not just a boolean value) be simulated? It seems that this is more complicated, since we need to keep track, somehow, of the output strings, which can be numerous because of the nondeterminism. First of all, some theory. The following are distinct algebraic structures: generators