uCalc API Version: 2.1.3-preview.2 Released: 6/16/2026

Warning

uCalc API Preview Release Notice:The documentation describes the intended behavior of the API. The current preview build contains incomplete features, unoptimized performance, and is subject to breaking changes.

{@Number}

Product: 

Class: 

Remarks

Description: A category matcher that identifies any token defined as a numeric value (e.g., 10, 3.14, 1e-5).

The {@Number} directive is used within a uCalc::Transformer to target numeric data. Because it operates at the tokenization level, it is more robust than a standard numeric regex. It understands the context of a number and treats it as a single unit, regardless of its format.

Supported Formats

By default, {@Number} recognizes:

  • Integers: 42
  • Decimals: 0.99
  • Scientific Notation: 6.022e23
  • Hex/Binary: 0xFF or 0b1010 (if configured in the engine)

Accuracy vs. Regex

A common regex like \d+ might accidentally match digits inside a variable name (like the 3 in data3). Because {@Number} queries the lexer, it only matches tokens that have been explicitly identified as numeric literals, ensuring your transformations don't corrupt variable identifiers.

Inverse Matching with !

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

  • {@Number}: Matches a numeric token.
  • {!Number}: Matches any token that is not a number (e.g., operators, strings, or keywords).

Examples

Matching by token type
				
					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=)>
				
					#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=)>
				
					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=)>
(Real World: Currency Formatter) Finding raw numbers in a text stream and converting them to a formatted currency string.
				
					using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();
t.FromTo("Price: {@Number:amt}", "Price: ${amt}");

string input = "Item A Price: 19.99, Item B Price: 5";
Console.WriteLine(t.Transform(input));
				
			
Item A Price: $19.99, Item B Price: $5
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto t = uc.NewTransformer();
   t.FromTo("Price: {@Number:amt}", "Price: ${amt}");

   string input = "Item A Price: 19.99, Item B Price: 5";
   cout << t.Transform(input) << endl;
}
				
			
Item A Price: $19.99, Item B Price: $5
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t = uc.NewTransformer()
      t.FromTo("Price: {@Number:amt}", "Price: ${amt}")
      
      Dim input As String = "Item A Price: 19.99, Item B Price: 5"
      Console.WriteLine(t.Transform(input))
   End Sub
End Module
				
			
Item A Price: $19.99, Item B Price: $5
Identifying all numbers in an expression and wrapping them in a "Num" tag.
				
					using uCalcSoftware;

var uc = new uCalc();
var t = new uCalc.Transformer();
t.FromTo("{@Number:n}", "Num({n})");

Console.WriteLine(t.Transform("price = 50 + 5.50"));
				
			
price = Num(50) + Num(5.50)
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   uCalc::Transformer t;
   t.FromTo("{@Number:n}", "Num({n})");

   cout << t.Transform("price = 50 + 5.50") << endl;
}
				
			
price = Num(50) + Num(5.50)
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t As New uCalc.Transformer()
      t.FromTo("{@Number:n}", "Num({n})")
      
      Console.WriteLine(t.Transform("price = 50 + 5.50"))
   End Sub
End Module
				
			
price = Num(50) + Num(5.50)
Verifying that `{@Number}` correctly ignores digits that are part of other tokens (like strings or identifiers).
				
					using uCalcSoftware;

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

// The '2' in 'var2' and the '100' in the string should NOT match
Console.WriteLine(t.Transform("""
var2 = "count is 100" + 50
"""));
				
			
var2 = "count is 100" + FOUND
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

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

   // The '2' in 'var2' and the '100' in the string should NOT match
   cout << t.Transform(R"(var2 = "count is 100" + 50)") << endl;
}
				
			
var2 = "count is 100" + FOUND
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t As New uCalc.Transformer()
      t.FromTo("{@Number}", "FOUND")
      
      '// The '2' in 'var2' and the '100' in the string should NOT match
      Console.WriteLine(t.Transform("var2 = ""count is 100"" + 50"))
   End Sub
End Module
				
			
var2 = "count is 100" + FOUND
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