uCalc API Version: 5.7.0-preview.1 Released: 7/30/2026

Warning

uCalc API Preview Release Notice:This preview documentation describes the intended behavior of the API. It is not fully accurate or complete.The current preview build contains incomplete features, unoptimized performance, and is subject to breaking changes.Use of the preview version in your production code is not recommended.

Whitespace

Product: 

Class: 

Whitespace behavior

Remarks

In uCalc, whitespace (spaces and tabs) is ignored by default. This means A + B matches A+B or A + B.

Important Distinction: unlike many other languages, uCalc defines Newlines by default as Statement Separators, not generic whitespace.

  • Spaces/Tabs: Ignored/Skipped by default. You can change this behavior using the WhitespaceSensitive property or the $ variable directive.
  • Newlines: Treated as a "stop" or "separator" (like a semicolon ; in C#). To treat them as spaces, you must redefine the token type.

Key Concepts

ConceptBehaviorExample
Default (Insensitive)Spaces in the pattern match any amount of horizontal whitespace (including none).Key : Value matches Key:Value and Key : Value
Newline BehaviorNewlines separate statements. By default they are not consumed by standard space characters in a pattern.A B matches A B but not A \n B (unless configured).
{@Whitespace}Explicitly captures a block of whitespace into a variable.{@Whitespace} captures whitespace characters such as spaces and tabs.
WhitespaceSensitiveIf set to True, block of whitespace in your pattern matches exactly one token in the source.A B matches A B but fails on A B.

Why uCalc? (Comparative Analysis)

  • vs. Regular Expressions:
    • Readability: In Regex, handling variable spacing requires cluttering your pattern with \s*. uCalc handles the "flexibility" automatically.
    • Structure: uCalc distinguishes between "formatting" (spaces) and "structure" (newlines), making it easier to parse line-based data formats (like CSV or Config files) without accidental matches across lines.
    • Configurability: It's easy to reconfigure newlines to behave as whitespace with t.Tokens["_token_newline"].TypeOfToken = TokenType::Whitespace;, for dealing with XML or HTML.

Examples

Whitespace

ID: 189

See: {@Self}, Whitespace 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();

t.FromTo("Hello World", "<{@Self}>");
Console.WriteLine(t.Transform("Hello World. HelloWorld. Hello     World. Hello, World."));
				
			
<Hello World>. HelloWorld. <Hello     World>. Hello, World.
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					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto t = uc.NewTransformer();

   t.FromTo("Hello World", "<{@Self}>");
   cout << t.Transform("Hello World. HelloWorld. Hello     World. Hello, World.") << endl;
}
				
			
<Hello World>. HelloWorld. <Hello     World>. Hello, World.
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t = uc.NewTransformer()
      
      t.FromTo("Hello World", "<{@Self}>")
      Console.WriteLine(t.Transform("Hello World. HelloWorld. Hello     World. Hello, World."))
   End Sub
End Module
				
			
<Hello World>. HelloWorld. <Hello     World>. Hello, World.
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WhitespaceSensitive()

ID: 142

See: DefaultRuleSet = [Rule], Whitespace, WhitespaceSensitive = [bool], WhitespaceSensitive(bool) 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();
var Text = "This is a test.";
var p = t.FromTo("This {words:3}", "[{words}]");

Console.WriteLine($"Input: {Text}");
Console.WriteLine($"Pattern: {p.Pattern}");
Console.WriteLine("");

Console.WriteLine("3 captured tokens are in brackets");
Console.WriteLine("");

Console.WriteLine($"WhitespaceSensitive = {t.DefaultRuleSet.WhitespaceSensitive}");
Console.WriteLine(t.Transform(Text));
Console.WriteLine("");

t.DefaultRuleSet.WhitespaceSensitive = true;
Console.WriteLine($"WhitespaceSensitive = {t.DefaultRuleSet.WhitespaceSensitive}");
Console.WriteLine(t.Transform(Text));

				
			
Input: This is a test.
Pattern: This {words:3}

3 captured tokens are in brackets

WhitespaceSensitive = False
[is a test].

WhitespaceSensitive = True
[ is ]a test.
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

#define tf(IsTrue) ((IsTrue) ? "True" : "False")

int main() {
   uCalc uc;
   auto t = uc.NewTransformer();
   auto Text = "This is a test.";
   auto p = t.FromTo("This {words:3}", "[{words}]");

   cout << "Input: " << Text << endl;
   cout << "Pattern: " << p.Pattern() << endl;
   cout << "" << endl;

   cout << "3 captured tokens are in brackets" << endl;
   cout << "" << endl;

   cout << "WhitespaceSensitive = " << tf(t.DefaultRuleSet().WhitespaceSensitive()) << endl;
   cout << t.Transform(Text) << endl;
   cout << "" << endl;

   t.DefaultRuleSet().WhitespaceSensitive(true);
   cout << "WhitespaceSensitive = " << tf(t.DefaultRuleSet().WhitespaceSensitive()) << endl;
   cout << t.Transform(Text) << endl;

}
				
			
Input: This is a test.
Pattern: This {words:3}

3 captured tokens are in brackets

WhitespaceSensitive = False
[is a test].

WhitespaceSensitive = True
[ is ]a test.
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t = uc.NewTransformer()
      Dim Text = "This is a test."
      Dim p = t.FromTo("This {words:3}", "[{words}]")
      
      Console.WriteLine($"Input: {Text}")
      Console.WriteLine($"Pattern: {p.Pattern}")
      Console.WriteLine("")
      
      Console.WriteLine("3 captured tokens are in brackets")
      Console.WriteLine("")
      
      Console.WriteLine($"WhitespaceSensitive = {t.DefaultRuleSet.WhitespaceSensitive}")
      Console.WriteLine(t.Transform(Text))
      Console.WriteLine("")
      
      t.DefaultRuleSet.WhitespaceSensitive = true
      Console.WriteLine($"WhitespaceSensitive = {t.DefaultRuleSet.WhitespaceSensitive}")
      Console.WriteLine(t.Transform(Text))
      
   End Sub
End Module
				
			
Input: This is a test.
Pattern: This {words:3}

3 captured tokens are in brackets

WhitespaceSensitive = False
[is a test].

WhitespaceSensitive = True
[ is ]a test.
Explore 600+ other examples
Transformer: Matching by tokens vs match by character; also whitespace sensitivity

ID: 155

See: Add(string, TokenType, string, int, RegExGrammar, int), Description = [string], Description(string), Tokens = [Tokens], Tokens, Whitespace 
				
					using uCalcSoftware;

var uc = new uCalc();
// This examples shows the default match by
// token mode, as well as how to reconfigure
// it in order to do match by character
// along with a whitespace variation

var t = uc.NewTransformer();
var txt = "This is an island test, I said.";
t.FromTo("is", "<is>");

Console.WriteLine(t.Transform(txt));
Console.WriteLine("");

t.Tokens.Description = "Match by character";
t.Tokens.Add("."); // This overrides existing tokens
t.FromTo("is", "<is>");
Console.WriteLine(t.Tokens.Description);
Console.WriteLine(t.Transform(txt));
Console.WriteLine("");

// Note: whitespace sensitivity is off by default
// Whitespace token is re-introduced
// (after being overridden in the previous Token Add())
t.Tokens.Description = "By char + whitespace ignored";
t.Tokens.Add("[\\t\\v ]+", TokenType.Whitespace);
t.FromTo("is", "<{@Self}>");
Console.WriteLine(t.Tokens.Description);
Console.WriteLine(t.Transform(txt));
				
			
This <is> an island test, I said.

Match by character
Th<is> <is> an <is>land test, I said.

By char + whitespace ignored
Th<is> <is> an <is>land test, <I s>aid.
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   // This examples shows the default match by
   // token mode, as well as how to reconfigure
   // it in order to do match by character
   // along with a whitespace variation

   auto t = uc.NewTransformer();
   auto txt = "This is an island test, I said.";
   t.FromTo("is", "<is>");

   cout << t.Transform(txt) << endl;
   cout << "" << endl;

   t.Tokens().Description("Match by character");
   t.Tokens().Add("."); // This overrides existing tokens
   t.FromTo("is", "<is>");
   cout << t.Tokens().Description() << endl;
   cout << t.Transform(txt) << endl;
   cout << "" << endl;

   // Note: whitespace sensitivity is off by default
   // Whitespace token is re-introduced
   // (after being overridden in the previous Token Add())
   t.Tokens().Description("By char + whitespace ignored");
   t.Tokens().Add("[\\t\\v ]+", TokenType::Whitespace);
   t.FromTo("is", "<{@Self}>");
   cout << t.Tokens().Description() << endl;
   cout << t.Transform(txt) << endl;
}
				
			
This <is> an island test, I said.

Match by character
Th<is> <is> an <is>land test, I said.

By char + whitespace ignored
Th<is> <is> an <is>land test, <I s>aid.
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      '// This examples shows the default match by
      '// token mode, as well as how to reconfigure
      '// it in order to do match by character
      '// along with a whitespace variation
      
      Dim t = uc.NewTransformer()
      Dim txt = "This is an island test, I said."
      t.FromTo("is", "<is>")
      
      Console.WriteLine(t.Transform(txt))
      Console.WriteLine("")
      
      t.Tokens.Description = "Match by character"
      t.Tokens.Add(".") '// This overrides existing tokens
      t.FromTo("is", "<is>")
      Console.WriteLine(t.Tokens.Description)
      Console.WriteLine(t.Transform(txt))
      Console.WriteLine("")
      
      '// Note: whitespace sensitivity is off by default
      '// Whitespace token is re-introduced
      '// (after being overridden in the previous Token Add())
      t.Tokens.Description = "By char + whitespace ignored"
      t.Tokens.Add("[\\t\\v ]+", TokenType.Whitespace)
      t.FromTo("is", "<{@Self}>")
      Console.WriteLine(t.Tokens.Description)
      Console.WriteLine(t.Transform(txt))
   End Sub
End Module
				
			
This <is> an island test, I said.

Match by character
Th<is> <is> an <is>land test, I said.

By char + whitespace ignored
Th<is> <is> an <is>land test, <I s>aid.
Explore 600+ other examples
Change newline from statement separator to whitespace

ID: 220

See: ByName, Whitespace 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();

t.Str("""

<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>

""");

t.Pattern("<div>{body}</div>");

Console.WriteLine("Newline as statement separator (default)");
Console.WriteLine("----------------------------------------");
Console.WriteLine(t.Find().Matches.Text);
Console.WriteLine("");

Console.WriteLine("Newline as whitespace");
Console.WriteLine("---------------------");
t.Tokens["_token_newline"].TypeOfToken = TokenType.Whitespace;
Console.WriteLine(t.Find().Matches.Text);
				
			
Newline as statement separator (default)
----------------------------------------
<div>a b c</div>
<div>1 2 3</div>

Newline as whitespace
---------------------
<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto t = uc.NewTransformer();

   t.Str(R"(
<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>
)");

   t.Pattern("<div>{body}</div>");

   cout << "Newline as statement separator (default)" << endl;
   cout << "----------------------------------------" << endl;
   cout << t.Find().Matches().Text() << endl;
   cout << "" << endl;

   cout << "Newline as whitespace" << endl;
   cout << "---------------------" << endl;
   t.Tokens()["_token_newline"].TypeOfToken(TokenType::Whitespace);
   cout << t.Find().Matches().Text() << endl;
}
				
			
Newline as statement separator (default)
----------------------------------------
<div>a b c</div>
<div>1 2 3</div>

Newline as whitespace
---------------------
<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t = uc.NewTransformer()
      
      t.Str("
<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>
")
      
      t.Pattern("<div>{body}</div>")
      
      Console.WriteLine("Newline as statement separator (default)")
      Console.WriteLine("----------------------------------------")
      Console.WriteLine(t.Find().Matches.Text)
      Console.WriteLine("")
      
      Console.WriteLine("Newline as whitespace")
      Console.WriteLine("---------------------")
      t.Tokens("_token_newline").TypeOfToken = TokenType.Whitespace
      Console.WriteLine(t.Find().Matches.Text)
   End Sub
End Module
				
			
Newline as statement separator (default)
----------------------------------------
<div>a b c</div>
<div>1 2 3</div>

Newline as whitespace
---------------------
<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>
Explore 600+ other examples
Change newline from statement separator to whitespace using TypeOfToken

ID: 221

See: TypeOfToken = [TokenType], Whitespace 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();

t.Str("""

<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>

""");

t.Pattern("<div>{body}</div>");
var NewLineToken = t.Tokens["_token_newline"];

Console.WriteLine("Newline as statement separator (default)");
Console.WriteLine("----------------------------------------");
Console.WriteLine(t.Find().Matches.Text);
Console.WriteLine("");

Console.WriteLine("Newline as whitespace");
Console.WriteLine("---------------------");
NewLineToken.TypeOfToken = TokenType.Whitespace;
Console.WriteLine(t.Find().Matches.Text);
				
			
Newline as statement separator (default)
----------------------------------------
<div>a b c</div>
<div>1 2 3</div>

Newline as whitespace
---------------------
<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto t = uc.NewTransformer();

   t.Str(R"(
<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>
)");

   t.Pattern("<div>{body}</div>");
   auto NewLineToken = t.Tokens()["_token_newline"];

   cout << "Newline as statement separator (default)" << endl;
   cout << "----------------------------------------" << endl;
   cout << t.Find().Matches().Text() << endl;
   cout << "" << endl;

   cout << "Newline as whitespace" << endl;
   cout << "---------------------" << endl;
   NewLineToken.TypeOfToken(TokenType::Whitespace);
   cout << t.Find().Matches().Text() << endl;
}
				
			
Newline as statement separator (default)
----------------------------------------
<div>a b c</div>
<div>1 2 3</div>

Newline as whitespace
---------------------
<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t = uc.NewTransformer()
      
      t.Str("
<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>
")
      
      t.Pattern("<div>{body}</div>")
      Dim NewLineToken = t.Tokens("_token_newline")
      
      Console.WriteLine("Newline as statement separator (default)")
      Console.WriteLine("----------------------------------------")
      Console.WriteLine(t.Find().Matches.Text)
      Console.WriteLine("")
      
      Console.WriteLine("Newline as whitespace")
      Console.WriteLine("---------------------")
      NewLineToken.TypeOfToken = TokenType.Whitespace
      Console.WriteLine(t.Find().Matches.Text)
   End Sub
End Module
				
			
Newline as statement separator (default)
----------------------------------------
<div>a b c</div>
<div>1 2 3</div>

Newline as whitespace
---------------------
<div>a b c</div>
<div>
x
y
z
</div>
<div>1 2 3</div>
Explore 600+ other examples
Turn new line into whitespace with Tokens.Add

ID: 175

See: Add(string, TokenType, string, int, RegExGrammar, int), Whitespace 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();
t.FromTo("<{tag}>{code}</{tag}>", "[{tag}]{code}[/{tag}]");
var MyStr = """
<div>Single line</div>
<div>Line 1
Line 2
Line 3
Line 4</div>
""";

Console.WriteLine("New line as statement separator (default)");
Console.WriteLine("");
Console.WriteLine(t.Transform(MyStr).Text);
Console.WriteLine("");

Console.WriteLine("New line as whitespace");
Console.WriteLine("");
t.Tokens.Add("[\\r\\n]+", TokenType.Whitespace);
Console.WriteLine(t.Transform(MyStr).Text);



				
			
New line as statement separator (default)

[div]Single line[/div]
<div>Line 1
Line 2
Line 3
Line 4</div>

New line as whitespace

[div]Single line[/div]
[div]Line 1
Line 2
Line 3
Line 4[/div]
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto t = uc.NewTransformer();
   t.FromTo("<{tag}>{code}</{tag}>", "[{tag}]{code}[/{tag}]");
   auto MyStr = R"(<div>Single line</div>
<div>Line 1
Line 2
Line 3
Line 4</div>)";

   cout << "New line as statement separator (default)" << endl;
   cout << "" << endl;
   cout << t.Transform(MyStr).Text() << endl;
   cout << "" << endl;

   cout << "New line as whitespace" << endl;
   cout << "" << endl;
   t.Tokens().Add("[\\r\\n]+", TokenType::Whitespace);
   cout << t.Transform(MyStr).Text() << endl;



}
				
			
New line as statement separator (default)

[div]Single line[/div]
<div>Line 1
Line 2
Line 3
Line 4</div>

New line as whitespace

[div]Single line[/div]
[div]Line 1
Line 2
Line 3
Line 4[/div]
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t = uc.NewTransformer()
      t.FromTo("<{tag}>{code}</{tag}>", "[{tag}]{code}[/{tag}]")
      Dim MyStr = "<div>Single line</div>
<div>Line 1
Line 2
Line 3
Line 4</div>"
      
      Console.WriteLine("New line as statement separator (default)")
      Console.WriteLine("")
      Console.WriteLine(t.Transform(MyStr).Text)
      Console.WriteLine("")
      
      Console.WriteLine("New line as whitespace")
      Console.WriteLine("")
      t.Tokens.Add("[\r\n]+", TokenType.Whitespace)
      Console.WriteLine(t.Transform(MyStr).Text)
      
      
      
   End Sub
End Module
				
			
New line as statement separator (default)

[div]Single line[/div]
<div>Line 1
Line 2
Line 3
Line 4</div>

New line as whitespace

[div]Single line[/div]
[div]Line 1
Line 2
Line 3
Line 4[/div]
Explore 600+ other examples
Using {@Whitespace} and {@Exec} to Count Indentation (for Python or YAML-like text)

ID: 223

See: {@Whitespace}, Whitespace 
				
					using uCalcSoftware;

var uc = new uCalc();
// Using {@Whitespace} to Count Indentation
// A common use case for parsing structured text (like Python or YAML)
// is capturing the exact whitespace at the start of a line.

uc.DefineVariable("IndentLen");

var t = uc.NewTransformer();
t.Text = "    Item 1"; // Indented by 4 spaces

// Capture the leading whitespace into 'w' and evaluate its length
t.FromTo("{@Whitespace:w} Item {id}", "<{@Self}>{@Exec: IndentLen = Length(w)}");
t.Transform();
// We can now analyze the captured whitespace
Console.WriteLine($"Indentation length: {uc.EvalStr("IndentLen")}");
				
			
Indentation length: 4
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   // Using {@Whitespace} to Count Indentation
   // A common use case for parsing structured text (like Python or YAML)
   // is capturing the exact whitespace at the start of a line.

   uc.DefineVariable("IndentLen");

   auto t = uc.NewTransformer();
   t.Text("    Item 1"); // Indented by 4 spaces

   // Capture the leading whitespace into 'w' and evaluate its length
   t.FromTo("{@Whitespace:w} Item {id}", "<{@Self}>{@Exec: IndentLen = Length(w)}");
   t.Transform();
   // We can now analyze the captured whitespace
   cout << "Indentation length: " << uc.EvalStr("IndentLen") << endl;
}
				
			
Indentation length: 4
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      '// Using {@Whitespace} to Count Indentation
      '// A common use case for parsing structured text (like Python or YAML)
      '// is capturing the exact whitespace at the start of a line.
      
      uc.DefineVariable("IndentLen")
      
      Dim t = uc.NewTransformer()
      t.Text = "    Item 1" '// Indented by 4 spaces
      
      '// Capture the leading whitespace into 'w' and evaluate its length
      t.FromTo("{@Whitespace:w} Item {id}", "<{@Self}>{@Exec: IndentLen = Length(w)}")
      t.Transform()
      '// We can now analyze the captured whitespace
      Console.WriteLine($"Indentation length: {uc.EvalStr("IndentLen")}")
   End Sub
End Module
				
			
Indentation length: 4
Explore 600+ other examples