-module(solarSystem).
-export([process_csv/1, is_numeric/1, parseALine/2, parse/1, expandT/1, expandT/2,
parseNames/1]).
parseALine(false, T) ->
T;
parseALine(true, T) ->
T.
parse([Name, Colour, Distance, Angle, AngleVelocity, Radius, "1" | T]) ->
T;%Where T is a list of names of other objects in the solar system
parse([Name, Colour, Distance, Angle, AngleVelocity, Radius | T]) ->
T.
parseNames([H | T]) ->
H.
expandT(T) ->
T.
expandT([], Sep) ->
[];
expandT([H | T], Sep) ->
T.
% https://rosettacode.org/wiki/Determine_if_a_string_is_numeric#Erlang
is_numeric(L) ->
S = trim(L, ""),
Float = (catch erlang:list_to_float(S)),
Int = (catch erlang:list_to_integer(S)),
is_number(Float) orelse is_number(Int).
trim(A) ->
A.
trim([], A) ->
A;
trim([32 | T], A) ->
trim(T, A);
trim([H | T], A) ->
trim(T, A ++ [H]).
process_csv(L) ->
X = parse(L),
expandT(X).
The problem is that it will calls process_csv/1
function in my module in a main
, L
will be a file like this:
[["name "," col"," dist"," a"," angv"," r "," ..."],["apollo11 ","white"," 0.1"," 0"," 77760"," 0.15"]]
Or like this:
["planets ","earth","venus "]
Or like this:
["a","b"]
I need to display it as follows:
apollo11 =["white", 0.1, 0, 77760, 0.15,[]];
Planets =[earth,venus]
a,b
[[59],[97],[44],[98]]
My problem is that no matter how I make changes, it can only show a part, and there are no symbols. The list cannot be divided, so I can't find a way. In addition, because Erlang is a niche programming language, I can't even find examples online. So, can anyone help me? Thank you, very much. In addition, I am restricted from using recursion.
1条答案
按热度按时间e1xvtsh31#
I think the first problem is that it is hard to link what you are trying to achieve with what your code says thus far. Therefore, this feedback maybe is not exactly what you are looking for, but might give some ideas.
Let's structure the problem into the common elements: (1) input, (2) process, and (3) output.
You mentioned that L will be a file, but I assume it is a line in a file, where each line can be one of the 3 (three) samples. In this regard, the samples also do not have consistent pattern.
For this, we can build a function to convert each line of the file into Erlang term and pass the result to the next step.
The question also do not mention the specific logic in parsing/processing the input. You also seem to care about the data type so we will convert and display the result accordingly. Erlang as a functional language will naturally be handling list, so on most cases we will need to use functions on
lists
moduleYou didn't specifically mention where you want to display the result (an output file, screen/erlang shell, etc), so let's assume you just want to display it in the standard output/erlang shell.
Sample file content
test1.txt
(please note the dot at the end of each line)Howto run:
solarSystem:process_file("/Users/macbook/Documents/test1.txt").
Sample Result:
Module code: