ambareesha7
I stuck with this text-file manipulation problem
i stuck with this problem,
i could read the text from text-file and index it but i could not update
I’m missing something
defmodule ReadText do
def read_text_file(file_name) do
case File.read(file_name) do
{:ok, text} ->
IO.puts("slice 1: #{String.slice(text, 3..8)}")
slice1 = IO.gets("slice 1 to replace: ")
String.replace(text, String.slice(text, 3..8), slice1, global: false)
IO.puts("slice 2: #{String.slice(text, 72..80)}")
slice2 = IO.gets("slice 2 to replace: ")
String.replace(text, String.slice(text, 72..80), slice2, global: false)
IO.puts("slice 3: #{String.slice(text, 86..91)}")
slice3 = IO.gets("slice 3 to replace: ")
String.replace(text, String.slice(text, 86..91), slice3, global: false)
IO.puts("slice 4: #{String.slice(text, 101..110)}")
slice4 = IO.gets("slice 4 to replace: ")
String.replace(text, String.slice(text, 101..110), slice4, global: false)
{:error, error} ->
IO.puts(error)
end
end
def get_replaceable_indexs(file_name) do
case File.read(file_name) do
{:ok, text} ->
text
|> String.split("")
|> Enum.with_index(fn v, i -> [i, v] end)
{:error, error} ->
IO.puts(error)
end
end
def open(file_path) do
File.open(file_path, [:read, :write], fn text ->
IO.read(text, :all)
end)
end
end
i tried in livebook to get dynamic index for square brockets and use this index as rang in String.slice(text, 3..8) but i’m missing the logic
i highly appreciate any help
thank you
Marked As Solved
pdgonzalez872
Seems like calling String.replace/3 solves this nicely? Maybe I’m missing something.
ExUnit.start()
defmodule Test do
use ExUnit.Case
describe "implementation for https://forum.elixirforum.com/t/i-stuck-with-this-text-file-manipulation-problem/41384" do
defmodule ReplaceVariablesImplementation do
def call(text, %{name: name, company: company, time: time, salesguy: salesguy} = _args) do
text
|> String.replace("[name]", name)
|> String.replace("[company]", company)
|> String.replace("[time]", time)
|> String.replace("[salesguy]", salesguy)
end
end
test "Replaces variables in text" do
# Do File.read!/1 to get the file contents. Using a variable for brevity.
text = """
Hi [name],
Thank you for your time in our office.
Thank you for booking at [company] for [time].
Regards
[salesguy]
"""
# Using a string for time for brevity, maybe this is your use case, maybe not.
args = %{name: "Jane", company: "", time: "2022/3/25 13:00", salesguy: "Joe"}
expected = """
Hi Jane,
Thank you for your time in our office.
Thank you for booking at for 2022/3/25 13:00.
Regards
Joe
"""
result = ReplaceVariablesImplementation.call(text, args)
assert result == expected
end
end
end
(the test passes)
Also Liked
al2o3cr
Values in Elixir are immutable (they cannot be changed once created) - functions like String.replace return a new binary.
You can rebind variables, however. For instance,
text = String.replace(text, String.slice(text, 72..80), slice2, global: false
After this line, the name text will refer to the result of String.replace instead of the original input.
General note: hardcoding numerical offsets that are passed to String.slice is very likely not what the problem is really looking for. Take a look at the Regex module for a better way to find sequences like “left square bracket followed by letters followed by right square bracket” and manipulate them.
dimitarvp
Using string slices is absolutely not what you want here. I’d tell you that you failed the interview if you showed that to me.
Look for ways to search [anything] in the source text and replace that. Regex is a good start and might even be good enough as a final solution.
ericgray
Great that’s a good way to learn. Try different things to see what works best for you. Regex patterns are good but they can be cryptic and hard to read. I think in this case where you know the shape of the data before hand binary pattern matching is easier in my opinion. Try a Regex and let us know what you come up with.
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