README.md

Project Frequencies

Create a Char Frequency App

You should use the Trie implemented in the previous TP

1. Create a Function that given any List [a] returns a Map a Int.

The Int is the count of the number of instances of a in the List

> frequencyMap [1, 2, 3, 1, 3, 1]
fromList [(1,3),(2,1),(3,2)]

2. Adapt the insert and insertionSort from TP1 to work with any Ord type

> insertionSort "PAPAYA"
"AAAPPY"
> insert 'T' $ insertionSort "PAPAYA"
"AAAPPTY"

3. Create a function that returns a List of Frequencies ordered by number of occurrences

The Frequency type, is defined by:

type Frequency = (Int, Char)

You should use the frequencyMap and insertionSort functions

You can also use the swap function from Data.Tuple

Examples:

> frequencies "PAPAYA"
[(1,'Y'),(2,'P'),(3,'A')]
> frequencies "Zapallo con Papa"
[(1,'P'),(1,'Z'),(1,'c'),(1,'n'),(2,' '),(2,'l'),(2,'o'),(2,'p'),(4,'a')]

4.Create a main function that:

• Takes as an argument a file name (Use getArgs)
• If the file name is not specified prints an error message
• Reads the file (Using readFile).
• Counts the frequencies of the letters in the file
• Prints the table of frequencies in REVERSE order (Starting from the higher ones).

> freq example.txt | head
' ': 292
'e': 148
'o': 124
't': 98
'h': 96
'n': 95
'a': 93
's': 92
'r': 68
'i': 65