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.

{@Bracket}

Product: 

Class: 

Remarks

Description: A category matcher that identifies any token defined as an opening bracket (e.g., (, [, {, or custom patterns like < or begin).

The {@Bracket} token directive is a high-level matcher within a uCalc::Transformer. Unlike a character literal, it does not look for a specific symbol; instead, it queries the uCalc engine to see if the next token in the input stream belongs to the Opening Bracket category.

The Power of Category Definition

By default, uCalc defines (, [, and { as opening brackets. However, these are not hard-coded. Because {@Bracket} relies on the underlying token definitions:

  • Multi-character support: If you define the word begin as an opening bracket, {@Bracket} will match it.
  • Customizability: You can add angle brackets (<) or remove default ones based on your language requirements.
  • Ambiguity Handling: Angle brackets are excluded by default to prevent conflict with mathematical "less-than" operators.

Integration with {@CloseBracket}

{@Bracket} matches only the opening component. To build patterns that capture content between brackets, it is used in tandem with {@CloseBracket} (Topic 804). This separation allows for granular control over how different styles of scopes are opened and closed.

Inverse Matching with !

You can invert the logic of this directive using the ! operator.

  • {@Bracket}: Matches any token that is an opening bracket.
  • {!Bracket}: Matches any token that is not an opening bracket.

This is extremely useful for "negative matching," such as identifying all content that exists outside of a bracketed scope.

Examples

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=)>
Explore 600+ other examples
Normalizing mixed input by replacing any opening bracket style with a standard parenthesis.

ID: 929

See: {@Bracket} 
				
					using uCalcSoftware;

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

Console.WriteLine(t.Transform("{ x + [ y ] }"));
				
			
( x + ( y ] }
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

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

   cout << t.Transform("{ x + [ y ] }") << endl;
}
				
			
( x + ( y ] }
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t As New uCalc.Transformer()
      t.FromTo("{@Bracket}", "(")
      
      Console.WriteLine(t.Transform("{ x + [ y ] }"))
   End Sub
End Module
				
			
( x + ( y ] }
Explore 600+ other examples
(Real World: Structure Identification) Labeling the start of complex data structures in a mixed text stream.

ID: 930

See: {@Bracket} 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = new uCalc.Transformer();
t.FromTo("{@Bracket}", "[START_SCOPE]");

string input = "func { data [ 1, 2 ] }";
Console.WriteLine(t.Transform(input));
				
			
func [START_SCOPE] data [START_SCOPE] 1, 2 ] }
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   uCalc::Transformer t;
   t.FromTo("{@Bracket}", "[START_SCOPE]");

   string input = "func { data [ 1, 2 ] }";
   cout << t.Transform(input) << endl;
}
				
			
func [START_SCOPE] data [START_SCOPE] 1, 2 ] }
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t As New uCalc.Transformer()
      t.FromTo("{@Bracket}", "[START_SCOPE]")
      
      Dim input As String = "func { data [ 1, 2 ] }"
      Console.WriteLine(t.Transform(input))
   End Sub
End Module
				
			
func [START_SCOPE] data [START_SCOPE] 1, 2 ] }
Explore 600+ other examples
(Negative Match) Ensuring that `{@Bracket}` does not match common "bracket-like" characters that are not in its definition (like angle brackets).

ID: 931

See: {@Bracket} 
				
					using uCalcSoftware;

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

// Angle brackets are not included in {@Bracket} by default
Console.WriteLine(t.Transform("vector <int>"));
				
			
vector <int>
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

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

   // Angle brackets are not included in {@Bracket} by default
   cout << t.Transform("vector <int>") << endl;
}
				
			
vector <int>
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t As New uCalc.Transformer()
      t.FromTo("{@Bracket}", "FOUND")
      
      '// Angle brackets are not included in {@Bracket} by default
      Console.WriteLine(t.Transform("vector <int>"))
   End Sub
End Module
				
			
vector <int>
Explore 600+ other examples
(Default Matching) Identifying any brackets and normalizing them to a standard parentheses.

ID: 923

See: {@Bracket}, {@CloseBracket}, Introduction 
				
					using uCalcSoftware;

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

Console.WriteLine(t.Transform("{a, b, c} f(x, y) [1, 2, 3];"));
				
			
(a, b, c) f(x, y) (1, 2, 3);
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

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

   cout << t.Transform("{a, b, c} f(x, y) [1, 2, 3];") << endl;
}
				
			
(a, b, c) f(x, y) (1, 2, 3);
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t As New uCalc.Transformer()
      t.FromTo("{@Bracket}", "(")
      t.FromTo("{@CloseBracket}", ")")
      
      Console.WriteLine(t.Transform("{a, b, c} f(x, y) [1, 2, 3];"))
   End Sub
End Module
				
			
(a, b, c) f(x, y) (1, 2, 3);
Explore 600+ other examples