We Keep Coding

How Can I Parse String and Get Random Sentences in C#?

I'm trying to figure out how to parse a string in this format into a tree like data structure of arbitrary depth.
and after that make random sentences.
"{{Hello,Hi,Hey} {world,earth},{Goodbye,farewell} {planet,rock,globe{.,!}}}"
where
, means or
{ means expand
} means collapse up to parent
for example, i want to get output like this:
1) hello world planet.
2) hi earth globe!
3) goodby planet.
and etc.

The input string must be parsed. Since it can contain nested braces, we need a recursive parser. But to begin with, we need a data model to represent the tree structure.
We can have three different types of items in this tree: text, a list representing a sequence and a list representing a choice. Let's derive three classes from this abstract base class:
abstract public class TreeItem
{
public abstract string GetRandomSentence();
}
The TextItem class simply returns its text as "random sentence":
public class TextItem : TreeItem
{
public TextItem(string text)
{
Text = text;
}
public string Text { get; }
public override string GetRandomSentence()
{
return Text;
}
}
The sequence concatenates the text of its items:
public class SequenceItem : TreeItem
{
public SequenceItem(List<TreeItem> items)
{
Items = items;
}
public List<TreeItem> Items { get; }
public override string GetRandomSentence()
{
var sb = new StringBuilder();
foreach (var item in Items) {
sb.Append(item.GetRandomSentence());
}
return sb.ToString();
}
}
The choice item is the only one using randomness to pick one random item from the list:
public class ChoiceItem : TreeItem
{
private static readonly Random _random = new();
public ChoiceItem(List<TreeItem> items)
{
Items = items;
}
public List<TreeItem> Items { get; }
public override string GetRandomSentence()
{
int index = _random.Next(Items.Count);
return Items[index].GetRandomSentence();
}
}
Note that the sequence and choice items both call GetRandomSentence() recursively on their items to descend the tree recursively.
This was the easy part. Now lets create a parser.
public class Parser
{
enum Token { Text, LeftBrace, RightBrace, Comma, EndOfString }
int _index;
string _definition;
Token _token;
string _text; // If token is Token.Text;
public TreeItem Parse(string definition)
{
_index = 0;
_definition = definition;
GetToken();
return Choice();
}
private void GetToken()
{
if (_index >= _definition.Length) {
_token = Token.EndOfString;
return;
}
switch (_definition[_index]) {
case '{':
_index++;
_token = Token.LeftBrace;
break;
case '}':
_index++;
_token = Token.RightBrace;
break;
case ',':
_index++;
_token = Token.Comma;
break;
default:
int startIndex = _index;
do {
_index++;
} while (_index < _definition.Length & !"{},".Contains(_definition[_index]));
_text = _definition[startIndex.._index];
_token = Token.Text;
break;
}
}
private TreeItem Choice()
{
var items = new List<TreeItem>();
while (_token != Token.EndOfString && _token != Token.RightBrace) {
items.Add(Sequence());
if (_token == Token.Comma) {
GetToken();
}
}
if (items.Count == 0) {
return new TextItem("");
}
if (items.Count == 1) {
return items[0];
}
return new ChoiceItem(items);
}
private TreeItem Sequence()
{
var items = new List<TreeItem>();
while (true) {
if (_token == Token.Text) {
items.Add(new TextItem(_text));
GetToken();
} else if (_token == Token.LeftBrace) {
GetToken();
items.Add(Choice());
if (_token == Token.RightBrace) {
GetToken();
}
} else {
break;
}
}
if (items.Count == 0) {
return new TextItem("");
}
if (items.Count == 1) {
return items[0];
}
return new SequenceItem(items);
}
}
It consists of a lexer, i.e., a low level mechanism to split the input text into tokens. We have have four kinds of tokens: text, "{", "}" and ",". We represent these tokens as
enum Token { Text, LeftBrace, RightBrace, Comma, EndOfString }
We also have added a EndOfString token to tell the parser that the end of the input string was reached. When the token is Text we store this text in the field _text. The lexer is implemented by the GetToken() method which has no return value and instead sets the _token field, to make the current token available in the two parsing methods Choice() and Sequence().
One difficulty is that when we encounter an item, we do not know whether it is a single item or whether it is part of a sequence or a choice. We assume that the whole sentence definition is a choice consisting of sequences, which gives sequences precedence over choices (like "*" has precedence over "+" in math).
Both Choice and Sequence gather items in a temporary list. If this list contains only one item, then this item will be returned instead of a choice list or a sequence list.
You can test this parser like this:
const string example = "{{Hello,Hi,Hey} {world,earth},{Goodbye,farewell} {planet,rock,globe{.,!}}}";
var parser = new Parser();
var tree = parser.Parse(example);
for (int i = 0; i < 20; i++) {
Console.WriteLine(tree.GetRandomSentence());
}
The output might look like this:
Goodbye rock
Hi earth
Goodbye globe.
Hey world
Goodbye rock
Hi earth
Hey earth
farewell planet
Goodbye globe.
Hey world
Goodbye planet
Hello world
Hello world
Goodbye planet
Hey earth
farewell globe!
Goodbye globe.
Goodbye globe.
Goodbye planet
farewell rock

I think that can be a complicated job, for that I used this tutorial, I strongly advice you to read the entire page to understand how this works.
First, you have to pass this "tree" as an array. You can parse the string, manually set the array or whatever. That's important because there isn't a good model for that tree model so it's better if you use a already available one. Also, it's important that if you want to set a correct grammar, you'll need to add "weight" to those words and tell the code how to correctly set and in what order.
Here is the code snippet:
using System;
using System.Text;
namespace App
{
class Program
{
static void Main(string[] args)
{
string tree = "{{Hello,Hi,Hey} {world,earth},{Goodbye,farewell} {planet,rock,globe{.,!}}}";
string[] words = { "Hello", "Hi", "Hey", "world", "earth", "Goodbye", "farewell", "planet", "rock", "globe" };
RandomText text = new RandomText(words);
text.AddContentParagraphs(12, 1, 3, 3, 3);
string content = text.Content;
Console.WriteLine(content);
}
}
public class RandomText
{
static Random _random = new Random();
StringBuilder _builder;
string[] _words;
public RandomText(string[] words)
{
_builder = new StringBuilder();
_words = words;
}
public void AddContentParagraphs(int numberParagraphs, int minSentences,
int maxSentences, int minWords, int maxWords)
{
for (int i = 0; i < numberParagraphs; i++)
{
AddParagraph(_random.Next(minSentences, maxSentences + 1),
minWords, maxWords);
_builder.Append("\n\n");
}
}
void AddParagraph(int numberSentences, int minWords, int maxWords)
{
for (int i = 0; i < numberSentences; i++)
{
int count = _random.Next(minWords, maxWords + 1);
AddSentence(count);
}
}
void AddSentence(int numberWords)
{
StringBuilder b = new StringBuilder();
// Add n words together.
for (int i = 0; i < numberWords; i++) // Number of words
{
b.Append(_words[_random.Next(_words.Length)]).Append(" ");
}
string sentence = b.ToString().Trim() + ". ";
// Uppercase sentence
sentence = char.ToUpper(sentence[0]) + sentence.Substring(1);
// Add this sentence to the class
_builder.Append(sentence);
}
public string Content
{
get
{
return _builder.ToString();
}
}
}
}

If the question is how to parse the text. I think maybe you can use the stack to parse it.
"{{Hello,Hi,Hey} {world,earth},{Goodbye,farewell} {planet,rock,globe{.,!}}}"
Basically, you push char in the stack when you read a char is not '}'. And when you get a '}', you pop from stack many time, until you reach a '{'.
But it has more details, because you have a rule ',' for OR.
The parsing is like do the calculation by stack. This is the way how you handle parenthesis for equation.

Update column value of CSV in C#

In the coding, I want to replace the column value of CSV. However, it can`t replace the value in CSV.
CSV file:
"Name","Age"
"michael","16"
"miko","15"
"Tom","24"
namespace ConsoleApp1
{
class Program
{
static void Main(string[] args)
{
string text = File.ReadAllText(#"C:\test.csv");
TestDataModel users = new TestDataModel();
text = users.Name.Replace("m", "n");
File.WriteAllText(#"C:\test.csv", text);
}
public class TestDataModel
{
public string Name { get; set; }
public int Age { get; set; }
}
}
}

there is a lot of misconception in code you provided, and some of the solutions for your problem might not be begginer friendly.
Especially when they are not 'global' solutions. For your case I tried to explain parts of code in comments
using System.Text.RegularExpressions;
var csvFilePath = #"C:\test.csv";
// Split csv file into lines instead of raw text.
string[] csvText = File.ReadAllLines(csvFilePath);
var models = new List<TestDataModel>();
// Regex that matches your CSV file.
// Explained here: https://regex101.com/r/t589CW/1
var csvRegex = new Regex("\"(.*)\",\"(.*)\"");
for (int i = 0; i < csvText.Length; i++)
{
// Skip headers of file.
// That is: "Name","Age"
if (i == 0)
{
continue;
}
// Check for potential white spaces at the end of the file.
if (string.IsNullOrWhiteSpace(csvText[i]))
{
continue;
}
models.Add(new TestDataModel
{
// Getting a name from regex group match.
Name = csvRegex.Match(csvText[i]).Groups[1].Value,
// Getting an age from regex group and parse it into integer.
Age = int.Parse(csvRegex.Match(csvText[i]).Groups[2].Value),
});
}
// Creating headers for altered CSV.
string alteredCsv = "\"Name\",\"Age\"\n";
// Loop through your models to modify them as you wish and add csv text in correct format.
foreach (var testDataModel in models)
{
testDataModel.Name = testDataModel.Name.Replace('m', 'n');
alteredCsv += $"\"{testDataModel.Name}\",\"{testDataModel.Age}\"\n";
}
var outputFilePath = #"C:\test2.csv";
File.WriteAllText(outputFilePath, alteredCsv);
public class TestDataModel
{
public string Name { get; set; }
public int Age { get; set; }
}
However this answer contains many topics that you might want to get familiar with such as:
Regex/Regex in C#
Data Serialization/Deserialization
Working with Linq
String templates
I/O Operations

Try this
public static void Replace()
{
string text = File.ReadAllText(#"C:\test.csv");
string _text = text.Replace("m", "n");
File.WriteAllText(#"C:\New_test.csv", _text);
}

checking for values in multiple if statement and storing multiple comments based on results

Can someone give me an example of the best way to return multiple comments from an if statement?
protected string CheckFacility(int FacilityId)
{
var cfacility = new List<string>();
BuildingPresenter b = new BuildingPresenter();
FunctionalAreaPresenter f = new FunctionalAreaPresenter();
if (b.GetBuildings(FacilityId) != null)
{
cfacility.Add("There are Functional Areas associated with this facility. ");
}
if (f.GetFunctionalAreas(FacilityId) != null)
{
cfacility.Add("There are Functional Areas associated with this facility. ");
}
var cfacilitystring = string.Join(",", cfacility);
I'm getting these errors.
Error 3 The best overloaded method match for 'string.Join(string, string[])' has some invalid arguments
Error 4 Argument 2: cannot convert from 'System.Collections.Generic.List' to 'string[]'

var shirtAttributes = new List<string>();
if (shirt.IsBlack)
{
shirtAttributes.Add("black");
}
if (shirt.IsLarge)
{
shirtAttributes.Add("large");
}
if (shirt.IsLongSleeve)
{
shirtAttributes.Add("long sleeve");
}
var shirtAttributesString = string.Join(",", shirtAttributes);
Output is something like: "black, long sleeve" or "black" or "large, long sleeve"

You have many ways to deal with that, you can create a class and override the ToString() method:
public class Shirt{
public Shirt(string color, string size, string sleeve)
{
Color =color;
Size=size;
Sleeve=sleeve;
}
public string Color {get;set;}
public string Size {get;set}
public string Sleeve {get;set}
public override string ToString(){
return string.Format("shirt is color :{0} , size :{1} and shleeve: {2}",Color,Size,Sleeve )
}
}
So when you run your program after initializing your class with values
Shirt myShirt = new Shirt("black","large","long");
if(myShirt.Color=="black"&& myShirt.Size=="large" && myShirt.Sleeve=="long")
{
return myShirt.ToString();
}
else{
return "no match";//or want you want
}
Hope it will help.

how to store types as variables and use them in parameters' type?

class constType
{
public static const Type messageType = typeof(int); // HOW TO DO THIS? 1st mark
public string[] GetArraySomehow()
{
return new string[sizeof(messageType)]; // HOW TO DO THIS? 2nd mark
}
}
class testTypeInClass
{
public void test(constType.messageType message) // HOW TO DO THIS? 3rd mark
{
}
}
Okay so this is really weird and strange I know but how can I do this?
1st mark: I have to store int's type as const variable and use it laterç
2nd mark: I have to get stored type's size (how many bytes does it equal?)
3rd mark: I have to use it as a parameter type.
Well Why I have to do this such thing:
I have to store a type (not so wide, just I know I'll use int8,16,32 etc)
and have to know what exactly bytes does it equal (1,2,4 etc..);
well first of all I have a method in one of my classes which uses switch statement and:
like this:
public string test (int messageIndex)
{
switch (messageIndex)
{
case 0:
return "etc.. etc..";
case 1231412:
return "whatever";
}
}
Firstly I had some method like this:
public int fixForSwitchStatement(byte[] messageIndex)
{
byte[] RValue = new byte[4];
for (int i = 0; i <= messageIndex.Length - 1; i++)
{
RValue[i] = messageIndex[i];
}
for (int i = messageIndex.Length; i <= 4 - messageIndex.Length - 1; i++)
{
RValue[i] = 0;
}
return BitConverter.ToInt32(RValue, 0);
}
I was passing byte or short to switch statement then I was converting to int (int was a specified type for me) and I wanted to make a redesign like this.
public string test (/* [what's the case limit? that I've determined?] */ messageIndex)
{
switch (messageIndex)
{
case 0:
return "etc.. etc..";
case 1231412:
return "whatever";
}
}
Because I don't want to use fixSwitch... method anymore. I just need a specified type for all of these concept.
Why I have to use fixSwitch instead of typecasting like (int)somethingByte?
Well in my one of classes there is a thing called communicationSize, its the messageIndex thing's maximum size in byte(s) that I have to declare. This is for my server-client project. There is a messageIndex thing being used as a request index what server and client requests from each other. And I'm limiting it with byte(s). For save some data space from connection.
// still is being written

I'm not sure what the goal is and the question has been edited in the meantime but heres some example code using generics that may help you further.
class constType<T> where T : struct
{
public T GetT()
{
return new T();
}
public string[] GetArraySomehow()
{
var len = Marshal.SizeOf(typeof(T));
return new string[len];
}
}
class testTypeInClass
{
public void test<T>(T message) where T : struct
{
}
}
class MyClass
{
void Test()
{
var constType = new constType<int>();
var typeInClass = new testTypeInClass();
var t = constType.GetT();
typeInClass.test(t);
}
}

Is there a good C# design pattern for parsing strings that when split have different amounts of data?

I am dealing with values delimited by commas sent to me as a string. The strings come in many different structures (meaning different data types in different locations of the string as well as varying amounts of data). So while one string might be represented as:
- common data,identifier,int,string,string,string.
Another might be represented as:
- common data,identifier,int,int,string,string,string.
Design goals:
Common parse method
Common validation (i.e. int.TryParse() returns true)
Readily able to add different structures
Is there a good design pattern, or combination of design patterns, that allows me to parse the values, check them, and return an object only if the right amount of values were pulled in and those values were the expected data types?
Note: I am dealing with more than 30 different string structures.

If all the lines start with common data, identifier, and then are followed by a variable but expected (i.e. known based on the identifier) set of values, then a table approach could work well. To continue your example, say you have two different types:
common data,identifier,int,string,string,string.
common data,identifier,int,int,string,string,string.
You can build a class that defines what you're looking for:
class ItemDesc
{
public string Ident { get; private set; }
public string Fields { get; private set; }
public ItemDesc(string id, string flds)
{
Ident = id;
Fields = flds;
}
}
The Fields property is just a string that contains one-character type descriptions for the variable data. That is, "isss" would be interpreted as int,string,string,string.
You can then build a Dictionary<string, ItemDesc> that you can use to look these up:
Dictionary<string, ItemDesc> ItemLookup = new Dictionary<string, ItemDesc>
{
{ "ItemType1", new ItemDesc("ItemType1", "isss") },
{ "ItemType2", new ItemDesc("ItemType2", "iisss") },
};
Now when you read a line, use string.Split() to split it into fields. Get the identifier, look it up the dictionary to get the item descriptions, and then parse the rest of the fields. Something like:
string line = GetLine();
var fields = line.Split(',');
// somehow get the identifier
string id = GetIdentifier();
ItemDesc desc;
if (!ItemLookup.TryGetValue(id, out desc))
{
// unrecognized identifier
}
else
{
int fieldNo = 3; // or whatever field is after the identifier
foreach (var c in desc.Fields)
{
switch (c)
{
case 'i' :
// try to parse an int and save it.
break;
case 's' :
// save the string
break;
default:
// error, unknown field type
break;
}
++fieldNo;
}
}
// at this point if no errors occurred, then you have a collection
// of parsed fields that you saved. You can now create your object.

would need little more details, based on your problem domain it could entirely change. but following seem to be the first set of patterns, they are ordered on suitability.
Interpreter
Strategy
Builder

Just split them using string.Split(), and then int.Parse() or int.TryParse() each int value in the resulting array as needed.
var myStrings = string.Split(sourceString);
int myint1 = int.Parse(myStrings[0]);

There are several ways of dealing with this. Here's a simple one (outputting just an object array):
class Template
{
// map identifiers to templates
static Dictionary<string, string> templates = new Dictionary<string, string>
{
{ "type1", "isss" },
{ "type2", "iisss" },
};
static bool ParseItem(string input, char type, out object output)
{
output = null;
switch (type)
{
case 'i':
int i;
bool valid = int.TryParse(input, out i);
output = i;
return valid;
case 's':
output = input;
return true;
}
return false;
}
public static object[] ParseString(string input)
{
string[] items = input.Split(',');
// make sure we have enough items
if (items.Length < 2)
return null;
object[] output = new object[items.Length - 2];
string identifier = items[1];
string template;
// make sure a valid identifier was specified
if (!templates.TryGetValue(identifier, out template))
return null;
// make sure we have the right amount of data
if (template.Length != output.Length)
return null;
// parse each item
for (int i = 0; i < template.Length; i++)
if (!ParseItem(items[i + 2], template[i], out output[i]))
return null;
return output;
}
}

If you're interested in returning actual objects instead of just object arrays, you can put metadata into the class definitions of the objects you're returning. Then when you get the object type you look for the metadata to figure out where to find its value in the input array. Here's a quick example:
namespace Parser
{
// create metadata attribute
class CsvPositionAttribute : Attribute
{
public int Position { get; set; }
public CsvPositionAttribute(int position)
{
Position = position;
}
}
// define some classes that use our metadata
public class type1
{
[CsvPosition(0)]
public int int1;
[CsvPosition(1)]
public string str1;
[CsvPosition(2)]
public string str2;
[CsvPosition(3)]
public string str3;
}
public class type2
{
[CsvPosition(0)]
public int int1;
[CsvPosition(1)]
public int int2;
[CsvPosition(2)]
public string str1;
[CsvPosition(3)]
public string str2;
[CsvPosition(4)]
public string str3;
}
public class CsvParser
{
public static object ParseString(string input)
{
string[] items = input.Split(',');
// make sure we have enough items
if (items.Length < 2)
return null;
string identifier = items[1];
// assume that our identifiers refer to a type in our namespace
Type type = Type.GetType("Parser." + identifier, false);
if (type == null)
return null;
object output = Activator.CreateInstance(type);
// iterate over fields in the type -- you may want to use properties
foreach (var field in type.GetFields())
// find the members that have our position attribute
foreach (CsvPositionAttribute attr in
field.GetCustomAttributes(typeof(CsvPositionAttribute),
false))
// if the item exists, convert it to the type of the field
if (attr.Position + 2 >= items.Length)
return null;
else
// ChangeType may throw exceptions on failure;
// catch them and return an error
try { field.SetValue(output,
Convert.ChangeType(items[attr.Position + 2],
field.FieldType));
} catch { return null; }
return output;
}
}
}