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.

{@String}

Product: 

Class: 

Remarks

Description: A category matcher that identifies any token defined as a string literal, supporting single, double, and triple quotes, as well as interpolated strings.

The {@String} directive is the primary tool for matching text literals in a uCalc::Transformer. It handles the structural complexity of delimiters and escaping automatically.

Supported Formats

  • Quotes: Matches 'Single', "Double", or """Triple""" quoted blocks.
  • Interpolation: Matches $"{expression}" patterns. Note that for pattern matching, the content within the braces { } is captured based on balanced syntax; it does not require the internal identifiers to be defined unless the expression is being evaluated.

Comparison with Specific Matchers

While {@String} captures any string literal, you can use more specific variants if your logic requires it:

  • {@dqs}: Matches only double-quoted strings.
  • {@sqs}: Matches only single-quoted strings.
  • {@String}: Matches any string.

Inverse Matching with !

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

  • {@String}: Matches any string literal.
  • {!String}: Matches any token that is not a string (e.g., numbers, identifiers, or operators).

Advanced Capture: Suffix Indexing

When capturing a string with a named variable (e.g., {@String:txt}), the captured value includes the surrounding quotes. uCalc provides a powerful shortcut to access only the inner content:

  • {txt(0)}: Returns the full string with quotes (e.g., "Hello").
  • {txt(1)}: Returns the "inner" content without quotes (e.g., Hello). {txt} defaults to {txt(1)}

This is particularly useful when converting code to data formats (like XML or JSON) where delimiters must be stripped or changed.

  • Why uCalc? Matching strings with regex is notoriously difficult due to escaping and greedy matching. {@String} leverages the lexer's pre-defined knowledge of where a string starts and ends, ensuring perfect accuracy even with nested quotes or escape characters.

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
Demonstrating the difference between the `(0)` and `(1)` index.

ID: 894

See: {@String}, Introduction 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = new uCalc.Transformer();
// Capture the string and show both versions in the replacement
t.FromTo("{@String:txt}", "With: {txt(0)}, Without: {txt(1)}, Default: {txt}");

Console.WriteLine(t.Transform("'uCalc'"));
				
			
With: 'uCalc', Without: uCalc, Default: uCalc
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   uCalc::Transformer t;
   // Capture the string and show both versions in the replacement
   t.FromTo("{@String:txt}", "With: {txt(0)}, Without: {txt(1)}, Default: {txt}");

   cout << t.Transform("'uCalc'") << endl;
}
				
			
With: 'uCalc', Without: uCalc, Default: uCalc
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()
      '// Capture the string and show both versions in the replacement
      t.FromTo("{@String:txt}", "With: {txt(0)}, Without: {txt(1)}, Default: {txt}")
      
      Console.WriteLine(t.Transform("'uCalc'"))
   End Sub
End Module
				
			
With: 'uCalc', Without: uCalc, Default: uCalc
Explore 600+ other examples
Converting quoted strings into XML-style elements by stripping the original quotes.

ID: 895

See: {@String} 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = new uCalc.Transformer();
// Use {s(1)} to get just the text inside the quotes
t.FromTo("msg = {@String:s}", "<message>{s(1)}</message>");

string input = """
msg = "Welcome to uCalc!"
""";
Console.WriteLine(t.Transform(input));
				
			
<message>Welcome to uCalc!</message>
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   uCalc::Transformer t;
   // Use {s(1)} to get just the text inside the quotes
   t.FromTo("msg = {@String:s}", "<message>{s(1)}</message>");

   string input = R"(msg = "Welcome to uCalc!")";
   cout << t.Transform(input) << endl;
}
				
			
<message>Welcome to uCalc!</message>
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()
      '// Use {s(1)} to get just the text inside the quotes
      t.FromTo("msg = {@String:s}", "<message>{s(1)}</message>")
      
      Dim input As String = "msg = ""Welcome to uCalc!"""
      Console.WriteLine(t.Transform(input))
   End Sub
End Module
				
			
<message>Welcome to uCalc!</message>
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(Real World: Sensitive Data Redaction) Masking the content of all string literals in a log or script, while preserving the non-string code structure.

ID: 896

See: {@String} 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = new uCalc.Transformer();
// Replace every string literal with a placeholder
t.FromTo("{@String}", """
"[REDACTED]"
""");

string log = """
UserLogin(id: 101, pass: 'secret123', name: "Admin")
""";
Console.WriteLine(t.Transform(log));
				
			
UserLogin(id: 101, pass: "[REDACTED]", name: "[REDACTED]")
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   uCalc::Transformer t;
   // Replace every string literal with a placeholder
   t.FromTo("{@String}", R"("[REDACTED]")");

   string log = R"(UserLogin(id: 101, pass: 'secret123', name: "Admin"))";
   cout << t.Transform(log) << endl;
}
				
			
UserLogin(id: 101, pass: "[REDACTED]", name: "[REDACTED]")
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()
      '// Replace every string literal with a placeholder
      t.FromTo("{@String}", """[REDACTED]""")
      
      Dim log As String = "UserLogin(id: 101, pass: 'secret123', name: ""Admin"")"
      Console.WriteLine(t.Transform(log))
   End Sub
End Module
				
			
UserLogin(id: 101, pass: "[REDACTED]", name: "[REDACTED]")
Explore 600+ other examples