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: 

Remarks

Description: A category matcher that identifies any token defined as whitespace, primarily horizontal spacing like spaces and tabs.

The {@Whitespace} directive (shorthand {@ws}) is used within a uCalc::Transformer to target non-printing characters used for spacing. Unlike many regular expression engines where \s includes newlines, uCalc typically distinguishes between horizontal whitespace ({@Whitespace}) and vertical whitespace ({@Newline}).

If you need for newline to be whitespace, you can modify it like this: Tokens["_token_newline"].TypeOfToken = TokenType::Whitespace;

Usage Context

In many parsers, whitespace is ignored or "skipped." However, when building a transformer that preserves formatting or cleans up code, {@Whitespace} allows you to precisely target and manipulate spacing without affecting the line structure.

  • Spaces and Tabs: Automatically matches standard ASCII spaces and horizontal tabs.
  • Token Boundaries: Because uCalc is token-aware, {@Whitespace} will not match characters inside a quoted string unless they have been explicitly tokenized as whitespace tokens by the engine.

Inverse Matching with !

The universal inversion operator ! can be applied to this category:

  • {@Whitespace}: Matches a space or tab.
  • {!Whitespace}: Matches any token that is not whitespace (e.g., numbers, identifiers, or punctuation).

Examples

{@Whitespace}

ID: 179

See: {@Whitespace}, Introduction 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();
t.FromTo("{@Whitespace}", ",");

Console.WriteLine(t.Transform("This is   a 'small test' about ' whitespace ' tokens."));
				
			
This,is,a,'small test',about,' whitespace ',tokens.
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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("{@Whitespace}", ",");

   cout << t.Transform("This is   a 'small test' about ' whitespace ' tokens.") << endl;
}
				
			
This,is,a,'small test',about,' whitespace ',tokens.
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					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t = uc.NewTransformer()
      t.FromTo("{@Whitespace}", ",")
      
      Console.WriteLine(t.Transform("This is   a 'small test' about ' whitespace ' tokens."))
   End Sub
End Module
				
			
This,is,a,'small test',about,' whitespace ',tokens.
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Matching by token type

ID: 176

See: {@Alphanumeric}, {@Bracket}, {@CloseBracket}, {@Newline}, {@Newline}, {@Number}, {@String}, {@Reducible}, {@StatementSeparator}, {@Whitespace}, Introduction 
				
					using uCalcSoftware;

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

t.FromTo("{@String:txt}", "<<InnerQuote={txt}><TxtWithQuotes={txt(0)}>>");
t.FromTo("{@Number:MyNum}", "<NumericValue={MyNum}>");
t.FromTo("{@Bracket:MyBrack}", "<Brack={MyBrack}>");
t.FromTo("{@CloseBracket:CloseBr}", "<CloseBrack={CloseBr}>");
t.FromTo("{@StatementSeparator:Sep}", "<Separator={Sep}>");
t.FromTo("{@Alphanumeric:alpha}", "<Alpha={alpha}>");
t.FromTo("{@Whitespace:ws}", "<whitespace count={@Eval: Length(ws)}>");
t.FromTo("{@Reducible:r}", "<Reducible={r}>");
t.FromTo("{@Newline}", "<New line{@Newline}>");

var s = """
This is   55.2*6 "Hello world";
'Single quote'(parenth)
""";

Console.WriteLine(t.Filter(s).Matches.Text);
				
			
<Alpha=This>
<whitespace count=1>
<Alpha=is>
<whitespace count=3>
<NumericValue=55.2>
<Reducible=*>
<NumericValue=6>
<whitespace count=1>
<<InnerQuote=Hello world><TxtWithQuotes="Hello world">>
<Separator=;>
<New line
>
<<InnerQuote=Single quote><TxtWithQuotes='Single quote'>>
<Brack=(>
<Alpha=parenth>
<CloseBrack=)>
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("{@String:txt}", "<<InnerQuote={txt}><TxtWithQuotes={txt(0)}>>");
   t.FromTo("{@Number:MyNum}", "<NumericValue={MyNum}>");
   t.FromTo("{@Bracket:MyBrack}", "<Brack={MyBrack}>");
   t.FromTo("{@CloseBracket:CloseBr}", "<CloseBrack={CloseBr}>");
   t.FromTo("{@StatementSeparator:Sep}", "<Separator={Sep}>");
   t.FromTo("{@Alphanumeric:alpha}", "<Alpha={alpha}>");
   t.FromTo("{@Whitespace:ws}", "<whitespace count={@Eval: Length(ws)}>");
   t.FromTo("{@Reducible:r}", "<Reducible={r}>");
   t.FromTo("{@Newline}", "<New line{@Newline}>");

   auto s = R"(This is   55.2*6 "Hello world";
'Single quote'(parenth))";

   cout << t.Filter(s).Matches().Text() << endl;
}
				
			
<Alpha=This>
<whitespace count=1>
<Alpha=is>
<whitespace count=3>
<NumericValue=55.2>
<Reducible=*>
<NumericValue=6>
<whitespace count=1>
<<InnerQuote=Hello world><TxtWithQuotes="Hello world">>
<Separator=;>
<New line
>
<<InnerQuote=Single quote><TxtWithQuotes='Single quote'>>
<Brack=(>
<Alpha=parenth>
<CloseBrack=)>
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("{@String:txt}", "<<InnerQuote={txt}><TxtWithQuotes={txt(0)}>>")
      t.FromTo("{@Number:MyNum}", "<NumericValue={MyNum}>")
      t.FromTo("{@Bracket:MyBrack}", "<Brack={MyBrack}>")
      t.FromTo("{@CloseBracket:CloseBr}", "<CloseBrack={CloseBr}>")
      t.FromTo("{@StatementSeparator:Sep}", "<Separator={Sep}>")
      t.FromTo("{@Alphanumeric:alpha}", "<Alpha={alpha}>")
      t.FromTo("{@Whitespace:ws}", "<whitespace count={@Eval: Length(ws)}>")
      t.FromTo("{@Reducible:r}", "<Reducible={r}>")
      t.FromTo("{@Newline}", "<New line{@Newline}>")
      
      Dim s = "This is   55.2*6 ""Hello world"";
'Single quote'(parenth)"
      
      Console.WriteLine(t.Filter(s).Matches.Text)
   End Sub
End Module
				
			
<Alpha=This>
<whitespace count=1>
<Alpha=is>
<whitespace count=3>
<NumericValue=55.2>
<Reducible=*>
<NumericValue=6>
<whitespace count=1>
<<InnerQuote=Hello world><TxtWithQuotes="Hello world">>
<Separator=;>
<New line
>
<<InnerQuote=Single quote><TxtWithQuotes='Single quote'>>
<Brack=(>
<Alpha=parenth>
<CloseBrack=)>
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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
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					#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
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Finding instances where there are two or more consecutive whitespace tokens and reducing them to a single space.

ID: 252

See: {@Whitespace} 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();
// Match two whitespace tokens and replace with one space
t.FromTo("{@Whitespace}", " ");

string messy = "var    x   =  100;";
Console.WriteLine(t.Transform(messy));
				
			
var x = 100;
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					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto t = uc.NewTransformer();
   // Match two whitespace tokens and replace with one space
   t.FromTo("{@Whitespace}", " ");

   string messy = "var    x   =  100;";
   cout << t.Transform(messy) << endl;
}
				
			
var x = 100;
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t = uc.NewTransformer()
      '// Match two whitespace tokens and replace with one space
      t.FromTo("{@Whitespace}", " ")
      
      Dim messy As String = "var    x   =  100;"
      Console.WriteLine(t.Transform(messy))
   End Sub
End Module
				
			
var x = 100;
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Replacing all horizontal whitespace with a visible underscore for debugging.

ID: 889

See: {@Whitespace} 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = new uCalc.Transformer();
t.FromTo("{@Whitespace}", "_");

Console.WriteLine(t.Transform("x = 10 + y"));
				
			
x_=_10_+_y
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					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   uCalc::Transformer t;
   t.FromTo("{@Whitespace}", "_");

   cout << t.Transform("x = 10 + y") << endl;
}
				
			
x_=_10_+_y
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					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t As New uCalc.Transformer()
      t.FromTo("{@Whitespace}", "_")
      
      Console.WriteLine(t.Transform("x = 10 + y"))
   End Sub
End Module
				
			
x_=_10_+_y
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