SegmentComparer 2.1.0

SegmentComparer

Identify what has been added, removed, and unchanged by comparing two segments.

• Target framework: net8.0
• NuGet: https://www.nuget.org/packages/SegmentComparer

Install

• dotnet CLI: dotnet add package SegmentComparer

Quick start

using System;
using System.Linq;
using SegmentComparer;
using SegmentComparer.Structure;

var comparer = new Comparer();

var original = "The quick brown fox";
var updated  = "The quick red fox";

// Defaults: includeTags=true, tagVisualType=2 (FullTagText), semanticGrouping=true, comparisonType=0 (words)
var result = comparer.CompareSegment("seg-1", original, updated);

// Simple projection of results
var added   = result.ComparisonUnits.Where(u => u.Type == ComparisonUnit.ComparisonType.New).Select(u => u.Text);
var removed = result.ComparisonUnits.Where(u => u.Type == ComparisonUnit.ComparisonType.Removed).Select(u => u.Text);
var same    = result.ComparisonUnits.Where(u => u.Type == ComparisonUnit.ComparisonType.Identical).Select(u => u.Text);

Console.WriteLine("Added: " + string.Join(", ", added));
Console.WriteLine("Removed: " + string.Join(", ", removed));
Console.WriteLine("Unchanged: " + string.Join(", ", same));

// Edit distance
int relative;
int distance = comparer.GetSegmentEditDistance(original, updated, out relative, includeTags: true);
Console.WriteLine($"Edit distance: {distance} of {relative}");

Preview: rebuilt string with highlighting

Markdown-safe (renders everywhere; strike-through for removed, plain text for added/unchanged):

• The quick brown red fox

HTML-styled (for environments that allow inline styles; added=blue, removed=red strike, identical=black): <div> The quick <span style="color:#d32f2f;text-decoration:line-through;text-decoration-thickness:2px;text-decoration-color:#d32f2f;"> brown</span> <span style="color:#1976d2;"> red</span> fox </div>

Note: nuget.org sanitizes styles, so the HTML colors may not render there. The Markdown-safe example will still show the strike-through.

How to generate this output

using System;
using System.Linq;
using System.Net;
using System.Text;
using SegmentComparer;
using SegmentComparer.Structure;

// 1) Compare
var comparer = new Comparer();
var original = "The quick brown fox";
var updated  = "The quick red fox";
var result   = comparer.CompareSegment("seg-1", original, updated);

// 2) Build Markdown-safe text (strike for removed, plain for others)
static string BuildMarkdown(ComparisonResult result)
{
    var sb = new StringBuilder();
    foreach (var u in result.ComparisonUnits)
    {
        var text = u.Text; // already plain text at this point
        switch (u.Type)
        {
            case ComparisonUnit.ComparisonType.Removed:
                sb.Append("~~").Append(text).Append("~~");
                break;
            default:
                sb.Append(text);
                break;
        }
    }
    return sb.ToString();
}

// 3) Build HTML with colors (blue added, red strike removed, black identical)
static string BuildHtmlInline(ComparisonResult result)
{
    string StyleFor(ComparisonUnit.ComparisonType t) => t switch
    {
        ComparisonUnit.ComparisonType.New       => "color:#1976d2;",
        ComparisonUnit.ComparisonType.Removed   => "color:#d32f2f;text-decoration:line-through;text-decoration-thickness:2px;text-decoration-color:#d32f2f;",
        _                                        => "color:#000;"
    };

    var sb = new StringBuilder();
    sb.Append("<div class=\"diff\">");
    foreach (var u in result.ComparisonUnits)
    {
        var text = WebUtility.HtmlEncode(u.Text);
        sb.Append("<span style=\"").Append(StyleFor(u.Type)).Append("\">")
          .Append(text)
          .Append("</span>");
    }
    sb.Append("</div>");
    return sb.ToString();
}

// Examples
var md   = BuildMarkdown(result);
var html = BuildHtmlInline(result);

Console.WriteLine("Markdown output:");
Console.WriteLine(md);

Console.WriteLine("\nHTML output:");
Console.WriteLine(html);

If you need character-level comparison, call CompareSegment with comparisonType: 1.

Attribution

AB testing icons created by Bharat Icons — Flaticon