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
Explore 600+ other examples