Swapping each letter in a string sequentially using R - r

Question

For those fellow DnD fans, I recently found the Ring of the Grammarian. Thus I am trying to make a quick script for generating a list of sensible words based on swapping letters from an input string. For example, I want to input "mage hand" and have the program return a list or dataframe which reads;
cage hand
...yada yada ...
mage band
mage land
...yada yada ...
mage bang
so far, I've only gotten as far as this:
dictionary<-data.frame(DICTIONARY)
spell.suggester<-function(x){
for (i in 1:nchar(x)) {
for (k in 1:length(letters)) {
res1<-gsub(pattern = x[i] ,replace = letters[k], x)
res2<-grep("\\bres1\\b",dictionary[,1],value = F)
if_else(res2>1,print(grep("\\bres1\\b",dictionary[,1],value = T)),"nonsense")
return()
}
}
}
spell.suggester(x = "mage hand")
but I end up with an error message which reads
character(0)
NULL
I haven't found any answers on stack using R. Could someone please help me with some suggestions and guidance?

Answer 1

Your major problem here is that you're trying to index each letter of a string, and R doesn't like letting you do that - it treats a string as a whole value, so attempting to index the letters fails.
To fix that, you can use strsplit to turn a string into a vector of individual characters that you can index as normal.
Your second issue the dictionary search seems a bit over-complicated; you can use %in% to check if a value is present in a vector.
The code below shows a minimal example of how to do this; it only works with single words, and relies on you having a decent dictionary to check valid words against.
# minimal example of valid word list
dictionary <- c("vane", "sane", "pane", "cane",
"bone", "bans", "bate", "bale")
spell.suggester<-function(spell){
#Split spell into a vector of single characters
spell_letters <- strsplit(spell,"")[[1]]
# Once for each letter in spell
for (i in 1:nchar(spell)) {
# Once for each letter in letters
for (k in 1:length(letters)) {
#If the letter isn't a space
if (spell_letters[i] != " "){
# Create a new word by changing one letter
word <-gsub(pattern = spell_letters[i] ,replace = letters[k], spell)
# If the word is in the list of valid words
if (word %in% dictionary){
# print the possibility
print(word)
}
}
}
}
}
spell.suggester(spell="bane")