Clojure mapping over strings
clojure, dictionary, higher-order-functions, string
Solution
Your `apply-rules-to-char` function appears to want a string (e.g. `"A"`), not a character (e.g. `\A`), which is what a string is made up of. In other words, your function needs to be able to work as `(apply-rules-to-char [["A" "B"]] \A)`, because that's what it will get from `map`.
Problem
I'm stumped in Clojure. I'm trying to write a system that transforms certain characters of a string based on simple rules that are encoded in pairs like this : ["A" "B"] is a rule to turn "A" into "B" I have a function "apply-rules-to-char" which takes a vector of such rules and a char, finds the first rule that matches and applies it. It seems to work ``` (apply-rules-to-char [["A" "B"]] "C") produces "C" (apply-rules-to-char [["A" "B"]] "A") produces "B" (apply-rules-to-char [["A" "B"]] "M") produces "M" ``` However when I now try to apply this across a string, using map ``` (map (partial apply-rules-to-char [["A" "B"]]) "CAM") ``` I get back ``` (\C \A \M) ``` In other words, it's run through the string "CAM" but hasn't done the transformation on the "A". Can anyone explain why this is? Update: Here's the definition of apply-rules-to-char. I'd guess it's not relevant because it always performs correctly when tested by itself. It's only in the map that it fails. ``` (defn apply-rules-to-char [rules c] (let [rule (first (filter #(applicable % c) rules))] (if (nil? rule) c (apply-rule-to-char rule c) ) )) ```