diff-match-patch
Diff Match Patch is a high-performance library in multiple languages that manipulates plain text.
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A javascript text differencing implementation.
Diff & patch JavaScript objects
Pretty diff to html javascript library (diff2html)
Quick Overview
Diff Match Patch is a library developed by Google that offers robust algorithms for comparing text, computing differences, and applying patches. It provides implementations in multiple programming languages, including JavaScript, Python, Java, C++, and Objective-C, making it versatile for various development environments.
Pros
- Cross-platform compatibility with implementations in multiple languages
- Robust algorithms for text comparison and patching
- Well-documented and maintained by Google
- Supports Unicode and handles special characters effectively
Cons
- May be overkill for simple text comparison tasks
- Performance can be slower for very large texts
- Learning curve for advanced features and customization
- Limited community contributions due to Google's ownership
Code Examples
- Creating a diff:
import diff_match_patch as dmp_module
dmp = dmp_module.diff_match_patch()
diff = dmp.diff_main("Hello World", "Goodbye World")
dmp.diff_cleanupSemantic(diff)
print(diff)
This code compares two strings and generates a list of differences.
- Applying a patch:
import diff_match_patch as dmp_module
dmp = dmp_module.diff_match_patch()
patches = dmp.patch_make("The quick brown fox jumps over the lazy dog.",
"The fast brown fox leaps over the lazy dog.")
result = dmp.patch_apply(patches, "The quick brown fox jumps over the lazy dog.")
print(result[0])
This example creates a patch from two strings and applies it to the original text.
- Fuzzy search:
import diff_match_patch as dmp_module
dmp = dmp_module.diff_match_patch()
pattern = "fox"
text = "The quick brown fox jumps over the lazy dog."
match = dmp.match_main(text, pattern, 0)
print(f"Match found at index: {match}")
This code performs a fuzzy search for a pattern within a text.
Getting Started
To use Diff Match Patch in your Python project:
-
Install the library:
pip install diff-match-patch -
Import the module in your Python script:
import diff_match_patch as dmp_module -
Create an instance of the diff_match_patch class:
dmp = dmp_module.diff_match_patch() -
Use the various methods provided by the library, such as
diff_main(),patch_make(), ormatch_main(), as shown in the code examples above.
Competitor Comparisons
A javascript text differencing implementation.
Pros of jsdiff
- More active development and maintenance
- Broader range of diff algorithms and options
- Better documentation and examples
Cons of jsdiff
- Larger file size and potentially higher memory usage
- Less cross-language support (primarily JavaScript-focused)
- May be overkill for simple text comparison tasks
Code Comparison
diff-match-patch:
dmp = diff_match_patch()
diff = dmp.diff_main("Hello World", "Goodbye World")
dmp.diff_cleanupSemantic(diff)
jsdiff:
import { diffWords } from 'diff';
const diff = diffWords('Hello World', 'Goodbye World');
console.log(diff);
Key Differences
- diff-match-patch offers a more comprehensive suite of tools for text manipulation, including patching and matching
- jsdiff provides more granular control over diff algorithms and output formats
- diff-match-patch has implementations in multiple languages, while jsdiff is primarily for JavaScript environments
- jsdiff offers more specialized diff functions (e.g., diffWords, diffChars, diffCss)
- diff-match-patch may be more suitable for complex text synchronization tasks, while jsdiff excels in web-based diff visualizations
Diff & patch JavaScript objects
Pros of jsondiffpatch
- Specialized for JSON structures, offering more precise diffing and patching for nested objects
- Provides visual diff rendering options for easy comparison
- Supports custom object equality checks and property filters
Cons of jsondiffpatch
- Limited to JSON data structures, less versatile for general text diffing
- May have higher overhead for simple string comparisons
- Less widely adopted compared to diff-match-patch
Code Comparison
diff-match-patch:
dmp = diff_match_patch()
patches = dmp.patch_make(text1, text2)
new_text = dmp.patch_apply(patches, text1)[0]
jsondiffpatch:
const delta = jsondiffpatch.diff(obj1, obj2);
jsondiffpatch.patch(obj1, delta);
const reverseDelta = jsondiffpatch.reverse(delta);
Key Differences
- diff-match-patch is language-agnostic and focuses on text diffing
- jsondiffpatch is JavaScript-specific and optimized for JSON structures
- diff-match-patch offers more robust text patching algorithms
- jsondiffpatch provides better visualization options for object differences
Use Cases
- diff-match-patch: General text diffing, collaborative editing, version control
- jsondiffpatch: API response comparison, JSON config management, object change tracking
Pretty diff to html javascript library (diff2html)
Pros of diff2html
- Generates visually appealing HTML output for diff comparisons
- Supports multiple programming languages with syntax highlighting
- Offers a web-based interface for easy integration into web applications
Cons of diff2html
- More focused on visualization rather than diff algorithm implementation
- May have higher overhead for simple text comparisons
- Less suitable for non-visual diff operations or backend processing
Code Comparison
diff-match-patch:
dmp = diff_match_patch()
diff = dmp.diff_main("Hello World", "Goodbye World")
dmp.diff_cleanupSemantic(diff)
diff2html:
const diff2html = require('diff2html');
const diffJson = diff2html.parse(diffInput);
const diffHtml = diff2html.html(diffJson, options);
Key Differences
diff-match-patch focuses on implementing efficient diff algorithms for text comparison, while diff2html specializes in rendering diff results as HTML. diff-match-patch is more suitable for core diff operations, while diff2html excels in presenting diff results visually.
diff-match-patch offers implementations in multiple programming languages, making it versatile for various environments. diff2html, on the other hand, is primarily JavaScript-based and tailored for web applications.
Choose diff-match-patch for robust diff algorithm implementation and cross-language support, or opt for diff2html when prioritizing visual presentation of diff results in web-based contexts.
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The Diff Match and Patch libraries offer robust algorithms to perform the operations required for synchronizing plain text.
- Diff:
- Compare two blocks of plain text and efficiently return a list of differences.
- Diff Demo
- Match:
- Given a search string, find its best fuzzy match in a block of plain text. Weighted for both accuracy and location.
- Match Demo
- Patch:
- Apply a list of patches onto plain text. Use best-effort to apply patch even when the underlying text doesn't match.
- Patch Demo
Originally built in 2006 to power Google Docs, this library is now available in C++, C#, Dart, Java, JavaScript, Lua, Objective C, and Python.
Reference
- API - Common API across all languages.
- Line or Word Diffs - Less detailed diffs.
- Plain Text vs. Structured Content - How to deal with data like XML.
- Unidiff - The patch serialization format.
- Support - Newsgroup for developers.
Languages
Although each language port of Diff Match Patch uses the same API, there are some language-specific notes.
A standardized speed test tracks the relative performance of diffs in each language.
Algorithms
This library implements Myer's diff algorithm which is generally considered to be the best general-purpose diff. A layer of pre-diff speedups and post-diff cleanups surround the diff algorithm, improving both performance and output quality.
This library also implements a Bitap matching algorithm at the heart of a flexible matching and patching strategy.
Top Related Projects
A javascript text differencing implementation.
Diff & patch JavaScript objects
Pretty diff to html javascript library (diff2html)
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