Stop writing the same utility functions in every Flutter project. This library contains 400+ production-hardened extension methods and utilities extracted from a real-world Flutter app with thousands of active users.
Production-Proven, Not Theoretical
These utilities aren't academic exercises—they're dog-fooded daily in Saropa Contacts, a production Flutter app available on both Google Play and the App Store. Every method has been refined through real user feedback and edge cases you only discover in production.
What this means for you:
- Edge cases already handled (empty strings, nulls, Unicode, timezone issues)
- Performance optimized for mobile devices
- API design proven intuitive through actual usage
- Bugs already found and fixed by real users
Why Choose This Library
| Before | After |
|---|---|
text != null && text.isNotEmpty ? text : fallback |
text.orDefault(fallback) |
if (date != null && date.isAfter(start) && date.isBefore(end)) |
date.isBetween(start, end) |
list.length > index ? list[index] : null |
list.itemAt(index) |
"${n}${n == 1 ? 'st' : n == 2 ? 'nd' : ...}" |
n.ordinal() |
| Writing regex for email extraction | text.between("@", ".") |
One import. Zero boilerplate. Full null-safety.
What's Included
| Category | Scope | Highlights |
|---|---|---|
| String | 110+ extensions, 30+ utils | Case conversion, truncation, wrapping, searching, grammar, diacritics, Unicode-safe ops; Levenshtein, slug/mask/template, diff (Myers), fuzzy search, excerpt, markdown, HTML sanitizer, name parsing |
| DateTime | 50+ extensions, 10+ utils | Age calculation, range checks, date arithmetic, leap years, week numbers; bounds, business days, duration format/parse, fiscal, relative, time rounding, injectable clock |
| List/Iterable | 40+ extensions | Safe access, deduplication, frequency analysis, order-independent comparison; chunks, partition, groupBy, run-length, binary search, rotate |
| Collections | 38 modules | LIS, LCS, sliding window, reservoir sampling, trie, disjoint set, Damerau–Levenshtein, knapsack, bloom filter, n-way merge, ring buffer, multiset, histogram, k-means, weighted interval, string pool, seeded shuffle, and more |
| Graph | 15 modules | BFS/DFS, Dijkstra, A*, connected components, topological sort, MST, critical path, bipartite, tree utils, DAG scheduler |
| Stats | 16 modules | Robust stats, moving average, normalization, quantile summary, correlation, linear regression, confidence intervals, funnel, retention, sampling, outlier (MAD), feature encoding |
| Validation | 12 modules | Validation errors, path/input shaping, guards, cross-field validation, safe temp names, password strength, PII detection, data redaction, safe parse, typed positives, IP/CIDR, JWT structure |
| Async | 22 modules | Debounce, throttle, delay, retry (with backoff/policy), memoize future, sequential/batch, cancel previous, semaphore, mutex, stream buffer/window, exponential backoff, circuit breaker, barrier, timeout policy, race/cancel, idempotent, heartbeat |
| Number | 25+ extensions, 15+ utils | Ordinals (1st, 2nd, 3rd), range clamping, digit ops; math (gcd, lcm), lerp, stats (variance, median, percentile), prime, factorial, locale format/parse, safe division |
| Map | 15+ extensions, 5+ utils | Nested access, pretty printing, null-safe ops; deep merge/copy, flatten keys, diff, invert, pick/omit, transform |
| Parsing | 22 modules | CSV, email, phone (E.164), Luhn, ISBN, SemVer, version compare, hex color, bool, list-from-string; config precedence, CSV dialect, canonicalize JSON, changelog section, JSON diff/patch, nested query, varint |
| Caching | 4 modules | LRU cache, TTL cache, size-limited cache, memoize (sync) |
| URL/Path | 8+ modules | Path join/extension/normalize, URL encode/query/build/absolute, path_more (directory, base name, bearer token) |
| Bool | 8+ | Flexible string parsing ("yes"/"1"/"true"), iterable analysis |
| Niche | 10+ | Color (hex/rgb, luminance, contrast), name (abbreviate, initials), pad/format, random string, hash, string diff, checksum, natural sort, UUID v4 |
| Object/Pipe | 12+ | Pipe, compose, once; nullable (whenNonNull, mapNonNull, tryCast); assert, coalesce, require, shallow copy, copyWithDefaults |
| Utilities | 25+ | JSON validation/type/iterables, Base64, UUID, Hex, HTML entities, gesture types, regex common/match, debug (testing) |
Installation
Run from your project directory:
flutter pub add saropa_dart_utils
Or for a pure Dart project:
dart pub add saropa_dart_utils
Then import it:
import 'package:saropa_dart_utils/saropa_dart_utils.dart';
For minimal bundle size, import only what you use (tree-shaking friendly):
import 'package:saropa_dart_utils/string/string_extensions.dart';
import 'package:saropa_dart_utils/datetime/date_time_extensions.dart';
import 'package:saropa_dart_utils/async/debounce_utils.dart'; // or throttle_utils, retry_utils, etc.
Quick Start Examples
Drop-in solutions for common Flutter development tasks:
String Extensions (110+ methods)
// Null safety
String? text;
text.isNullOrEmpty; // true
"hello".notNullOrEmpty; // true
// Case manipulation
"hello world".titleCase(); // "Hello world"
"hello world".capitalizeWords(); // "Hello World"
// Formatting
"Saropa".wrapSingleQuotes(); // 'Saropa'
"Saropa".encloseInParentheses(); // (Saropa)
// Truncation
"Long text here".truncateWithEllipsis(10); // "Long text…"
// Cleaning
"www.saropa.com".removeStart("www."); // "saropa.com"
" extra spaces ".compressSpaces(); // "extra spaces"
"abc123".removeNonNumbers(); // "123"
// Searching
"test@example.com".between("@", "."); // "example"
// Grammar
"apple".pluralize(3); // "apples"
"John".possess(); // "John's"
"apple".grammarArticle(); // "an"
// Diacritics
"cafe".removeDiacritics(); // "cafe"
DateTime Extensions (50+ methods)
DateTime date = DateTime(2024, 1, 15);
// Comparisons
date.isToday();
date.isBeforeNow();
date.isSameDateOnly(otherDate);
date.isBetween(start, end);
// Manipulation
date.addYears(1);
date.addMonths(2);
date.addDays(10);
date.nextDay();
date.prevDay();
// Age calculation
DateTime(1990, 5, 15).calculateAgeFromNow();
birthDate.isUnder13();
// List generation
DateTime.now().generateDayList(7); // Next 7 days
List Extensions (30+ methods)
// Comparison
[1, 2, 3].equalsIgnoringOrder([3, 2, 1]); // true
['a', 'a', 'b'].topOccurrence(); // 'a'
// Safe access
[1, 2, 3].itemAt(10); // null (no exception)
// Null-safe operations
items.addIfNotNull(maybeNull);
// Deduplication
[1, 2, 2, 3].unique(); // [1, 2, 3]
Number Extensions (25+ methods)
// Ordinals
1.ordinal(); // "1st"
22.ordinal(); // "22nd"
// Range operations
15.forceBetween(1, 10); // 10
5.isBetween(1, 10); // true
// Digit counting
12345.countDigits(); // 5
Iterable Extensions (10+ methods)
[1, 2, 3, 4, 5].randomElement();
[1, 2, 3].containsAll([1, 2]);
[1, 2, 3, 4, 5].countWhere((n) => n > 3); // 2
Map Extensions (15+ methods)
{'name': 'John', 'age': 30}.formatMap(); // Pretty print
data.removeKeys(['a', 'c']);
Bool Extensions (8+ methods)
"true".toBool(); // true
[true, true, true].allTrue; // true
[false, false].allFalse; // true
Enum Extensions (2+ methods)
enum Status { active, inactive }
Status.values.byNameTry("active"); // Status.active
Status.values.byNameTry("invalid"); // null (safe)
Status.values.byNameTry("ACTIVE", caseSensitive: false); // Status.active
Utility Classes (25+ methods)
// Hex
HexUtils.intToHex(255); // "FF"
HexUtils.hexToInt("FF"); // 255
// Random
CommonRandom.randomInt(1, 10);
CommonRandom.randomDouble(0.0, 1.0);
// URL
Uri.parse("https://example.com?key=value").hasQueryParameter("key"); // true
Async (debounce, throttle, retry, circuit breaker, and more)
// Debounce a callback (no-arg)
final debouncedSearch = debounce(() => fetchSuggestions(), Duration(milliseconds: 300));
debouncedSearch(); // call when user types; runs after 300 ms of no further calls
// Retry with exponential backoff
final result = await retryWithBackoff(() => http.get(uri), maxAttempts: 3);
// Limit concurrency
final semaphore = AsyncSemaphore(2);
await semaphore.run(() => heavyWork());
Collections, Graph, Stats, Validation
// Longest increasing subsequence (top-level function)
lisLength([3, 1, 4, 1, 5, 9, 2, 6]); // 4
// Shortest distances from source (Dijkstra)
final distances = dijkstraDistances(weightedGraph, source);
// Safe parsing (no-throw, returns ParseOk/ParseErr)
final result = safeParse(int.parse, formValue);
final width = result.valueOrNull; // int? (null if parse failed)
Real-World Use Cases
These aren't contrived examples—they're patterns we use constantly:
// User profile display
String displayName = user.firstName.capitalizeWords();
String initials = "${user.firstName.firstChar}${user.lastName.firstChar}";
String age = birthDate.calculateAgeFromNow().toString();
// Form validation
bool isValidInput = email.notNullOrEmpty && phone.removeNonNumbers().length >= 10;
// Date logic for subscriptions
bool isTrialActive = signupDate.addDays(14).isAfterNow();
bool isBirthdayThisMonth = birthDate.isSameMonth(DateTime.now());
// Safe API response handling
String? city = response['address']?.getChildString('city');
List<String> tags = (response['tags'] as List?)?.unique() ?? [];
// UI text formatting
String preview = longDescription.truncateWithEllipsis(100);
String itemCount = "item".pluralize(cart.length); // "1 item" or "5 items"
Finding opportunities in your project
A CLI tool scans Dart files and suggests places where saropa_dart_utils can replace boilerplate (e.g. x == null || x.isEmpty → x.isNullOrEmpty, s ?? '' → s.orEmpty()). Run from this repo:
# With path: non-interactive, report to stdout (e.g. for CI)
dart run tool/suggest_saropa_utils.dart /path/to/your/flutter_app
# Without path: interactive — asks Y/N/? for directory, output format, and apply
dart run tool/suggest_saropa_utils.dart
dart run tool/suggest_saropa_utils.dart --help
Only [path], --help, and --version are accepted. Interactive prompts ask for directory, report vs JSON, and whether to apply (apply not yet implemented). Type ? on any prompt for help. No edits are made; use the report to refactor manually.
Lint configuration
This package uses saropa_lints. Some rules are disabled for a pure Dart utility library (e.g. barrel file for the main entry point, non-ASCII in source for Unicode handling, static state for shared RegExp/constants). Others are satisfied by code fixes or inline suppressions (e.g. collapsed ifs in json_utils, named booleans in html_utils, redundant else removed, long-parameter-list and similar-names suppressed where intentional). Rationale for each override or resolution is in analysis_options_custom.yaml.
Documentation
- API Reference — Full method documentation with examples
- GitHub — Source code and issue tracking
- Changelog — Version history
Contributing
We welcome contributions! These utilities grew from solving real problems—if you've got a helper that's saved you time, it might help others too.
About Saropa
Saropa builds technology for personal safety and emergency preparedness. This utility library was extracted from Saropa Contacts—our production Flutter app for managing trusted emergency contacts—because we believe good utilities should be shared, not rewritten.
Libraries
- async/async_barrier_utils
- Async barrier: wait for N events — roadmap #676.
- async/async_more_utils
- async/async_mutex_utils
- Async mutex with tryLock — roadmap #652.
- async/async_semaphore_utils
- Async semaphore with permits (roadmap #651).
- async/batch_async_utils
- async/batch_flush_utils
- Batch/flush: collect events and flush on size/time — roadmap #671.
- async/cancel_previous_exception
- async/circuit_breaker_utils
- Circuit breaker (open/half-open/closed) — roadmap #657.
- async/debounce_utils
- async/delay_utils
- async/exponential_backoff_utils
- Exponential backoff helper (roadmap #677).
- async/heartbeat_utils
- Heartbeat/keepalive for long-running tasks — roadmap #675.
- async/idempotent_async_utils
- Idempotent async wrapper (deduplicate concurrent calls by key) — roadmap #668.
- async/memoize_future_utils
- async/race_cancel_utils
- Race with cancellation (first success wins, cancel rest) — roadmap #667.
- async/retry_policy_utils
- Retry policy (fixed, backoff, jitter) — roadmap #656.
- async/retry_utils
- async/sequential_async_utils
- async/stream_buffer_utils
- Stream buffering (bufferCount, bufferTime-style) — roadmap #664.
- async/stream_window_utils
- Stream windowing (time- and count-based) — roadmap #660.
- async/throttle_utils
- async/timeout_fallback_utils
- async/timeout_policy_utils
- Async timeout with fallback — roadmap #669.
- base64/base64_utils
- base64/gzip_codec_io
- IO-based gzip implementation using
dart:io. - base64/gzip_codec_stub
- bool/bool_iterable_extensions
- bool/bool_string_extensions
- caching/lru_cache
- caching/memoize_sync_utils
- caching/size_limit_cache
- caching/ttl_cache
- collections/balanced_partition_utils
- Balanced partitioning (K partitions with similar sums) — roadmap #474.
- collections/bimap_utils
- Bi-directional map (key↔value both unique) — roadmap #514.
- collections/bin_packing_utils
- Greedy bin packing (items into bins with capacities) — roadmap #475.
- collections/bloom_filter_utils
- Bloom filter with tunable false positive rate — roadmap #455.
- collections/chunk_overlap_utils
- Chunk + overlap windows for streaming — roadmap #465.
- collections/columnar_view_utils
- Columnar view of list<Map<String, Object?>> for analytics — roadmap #470.
- collections/damerau_levenshtein_utils
- Edit distance with transpositions (Damerau–Levenshtein) — roadmap #443.
- collections/dedup_set_expiry_utils
- Deduplicating set with expiry (for idempotency) — roadmap #511.
- collections/difference_array_utils
- Difference arrays for efficient range updates — roadmap #484.
- collections/disjoint_set_utils
- Disjoint-set / union-find with path compression (roadmap #496).
- collections/greedy_set_cover_utils
- Greedy set cover approximation — roadmap #447.
- collections/histogram_utils
- Histogram builder with fixed and quantile-based bins — roadmap #473.
- collections/interval_scheduling_utils
- Interval scheduling: max non-overlapping intervals (roadmap #445).
- collections/inverted_index_utils
- In-memory inverted index for small datasets — roadmap #456.
- collections/kmeans_utils
- K-means clustering (small K, small N) — roadmap #449.
- collections/knapsack_utils
- 0/1 Knapsack solver with reconstruction — roadmap #444.
- collections/lcs_substring_utils
- Longest common substring (not subsequence) for two lists/strings (roadmap #442).
- collections/lis_utils
- Longest increasing subsequence (LIS) with reconstruction (roadmap #441).
- collections/multi_criteria_sort_utils
- Multi-criteria sort with weighted comparators — roadmap #462.
- collections/multiset_utils
- Multi-set (bag) union/intersection/difference — roadmap #464.
- collections/nway_merge_utils
- N-way merge of multiple sorted iterables — roadmap #457.
- collections/online_mean_variance_utils
- Online mean/variance for numeric streams — roadmap #466.
- collections/pivot_unpivot_utils
- Pivot and unpivot for tabular data (list of maps) — roadmap #469.
- collections/prefix_frequency_utils
- Prefix frequency table (for autocomplete) — roadmap #481.
- collections/priority_map_utils
- Priority map (priority -> queues) — roadmap #528.
- collections/reservoir_sampling_utils
- Reservoir sampling for streaming data (roadmap #452).
- collections/ring_buffer_utils
- Ring buffer (bounded queue with overwrite) — roadmap #500.
- collections/rolling_hash_utils
- Rolling hash (Rabin–Karp style) for substring search — roadmap #482.
- collections/row_column_table_utils
- Row-oriented vs column-oriented table conversion — roadmap #525.
- collections/run_detection_utils
- Run detection (equal or increasing sequences with metadata) — roadmap #472.
- collections/seeded_shuffle_utils
- Deterministic shuffler with seed — roadmap #529.
- collections/sliding_window_aggregate_utils
- Sliding window aggregations (min/max/sum/avg over moving window) — roadmap #451.
- collections/stream_quantile_utils
- Stream quantile estimation (P²-style approximate) — roadmap #453.
- collections/string_pool_utils
- Memory-conscious string pool (deduplicate repeating strings) — roadmap #518.
- collections/time_bucket_utils
- Time-bucketed aggregation — roadmap #468.
- collections/top_k_heap_utils
- Top-K by key via min-heap — roadmap #459.
- collections/trie_utils
- Trie (prefix tree) with insert/delete/prefix search (roadmap #491).
- collections/weighted_interval_utils
- Weighted interval scheduling (max weight, DP) — roadmap #446.
- collections/window_functions_utils
- Window functions (lag, lead, row_number) over ordered data — roadmap #471.
- datetime/date_constant_extensions
- datetime/date_constants
- datetime/date_time_arithmetic_extensions
- datetime/date_time_bounds_extensions
- datetime/date_time_business_days_utils
- datetime/date_time_calendar_extensions
- datetime/date_time_clamp_extensions
- datetime/date_time_comparison_extensions
- datetime/date_time_extensions
- datetime/date_time_fiscal_extensions
- datetime/date_time_list_extensions
- datetime/date_time_more_extensions
- datetime/date_time_nullable_extensions
- datetime/date_time_overlap_utils
- datetime/date_time_range_utils
- datetime/date_time_relative_utils
- datetime/date_time_timezone_extensions
- datetime/date_time_utils
- datetime/date_time_week_extensions
- datetime/duration_format_utils
- datetime/duration_parse_utils
- datetime/injectable_clock_utils
- Injectable clock for tests (consistent "now") — roadmap #614.
- datetime/period_split_utils
- Period splitting (by month/week) — roadmap #610.
- datetime/relative_date_bucket_utils
- Relative date bucketing ("today", "yesterday", "last 7 days") — roadmap #616.
- datetime/time_emoji_utils
- datetime/time_rounding_utils
- Flexible time rounding (nearest 5/10/15 min, ceiling/floor) — roadmap #600.
- datetime/timebox_exception
- Timebox: run within time budget — roadmap #618.
- double/double_extensions
- double/double_iterable_extensions
- enum/enum_iterable_extensions
- gesture/gesture_utils
- gesture/swipe_properties
- graph/astar_utils
- A* shortest path with pluggable heuristic — roadmap #534.
- graph/bfs_dfs_utils
- BFS/DFS traversal with hooks (roadmap #532).
- graph/bipartite_utils
- Bipartite graph check and partitioning — roadmap #546.
- graph/connected_components_utils
- Connected components (and optionally SCC) — roadmap #537.
- graph/critical_path_utils
- Critical path (longest path in DAG) — roadmap #550.
- graph/dag_scheduler_utils
- DAG-based task scheduler (topological + priorities) — roadmap #558.
- graph/dijkstra_utils
- Dijkstra shortest path on weighted graphs (roadmap #533).
- graph/floyd_warshall_utils
- All-pairs shortest paths (Floyd–Warshall) — roadmap #536.
- graph/graph_diff_utils
- Graph diff (added/removed/changed edges) — roadmap #553.
- graph/graph_utils
- Graph representation helpers: adjacency list / weighted edges (roadmap #531).
- graph/hierarchy_utils
- Hierarchy flattener and builder from flat list with parent ids — roadmap #556, #557.
- graph/line_simplify_utils
- Line simplification (Douglas–Peucker) — roadmap #547.
- graph/mst_utils
- Minimum spanning tree (Kruskal) — roadmap #538.
- graph/topological_sort_utils
- Topological sort with cycle detection — roadmap #539.
- graph/tree_utils
- Tree utilities (LCA, depth, subtree size) — roadmap #555.
- hex/hex_utils
- html/html_entity_data
- html/html_utils
- int/int_extensions
- int/int_iterable_extensions
- int/int_nullable_extensions
- int/int_string_extensions
- int/int_utils
- iterable/comparable_iterable_extensions
- iterable/iterable_cartesian_extensions
- iterable/iterable_diff_extensions
- iterable/iterable_extensions
- iterable/iterable_first_last_extensions
- iterable/iterable_flatten_deep_extensions
- iterable/iterable_flatten_extensions
- iterable/iterable_group_by_extensions
- iterable/iterable_indexed_extensions
- iterable/iterable_list_ops_extensions
- iterable/iterable_min_max_extensions
- iterable/iterable_more_extensions
- iterable/iterable_pairs_extensions
- iterable/iterable_sort_extensions
- iterable/iterable_split_extensions
- iterable/iterable_symmetric_diff_extensions
- iterable/occurrence
- iterable/run_length_utils
- json/json_epoch_scale
- json/json_iterables_utils
- json/json_type_utils
- json/json_utils
- list/list_binary_search_extensions
- list/list_default_empty_extensions
- list/list_extensions
- list/list_lower_extensions
- list/list_nullable_extensions
- list/list_of_list_extensions
- list/list_rotate_extensions
- list/list_shuffle_seeded_extensions
- list/list_string_extensions
- list/list_top_k_extensions
- list/make_list_extensions
- list/unique_list_extensions
- map/deep_equality_utils
- Deep equality for nested maps and lists.
- map/map_deep_merge_extensions
- map/map_deep_utils
- map/map_default_extensions
- map/map_diff_utils
- map/map_extensions
- map/map_flatten_extensions
- map/map_from_entries_extensions
- map/map_invert_extensions
- map/map_merge_extensions
- map/map_more_extensions
- map/map_nested_extensions
- map/map_nullable_extensions
- map/map_pick_omit_extensions
- map/map_transform_extensions
- niche/checksum_utils
- niche/color_utils
- niche/hash_utils
- niche/name_utils
- niche/natural_sort_utils
- niche/niche_more_utils
- niche/pad_format_utils
- niche/random_string_utils
- niche/string_diff_utils
- num/math_utils
- GCD, LCM, and related integer math.
- num/num_clamp_extensions
- num/num_compact_parse_extensions
- num/num_extensions
- num/num_factorial_utils
- num/num_format_extensions
- num/num_iterable_extensions
- num/num_lerp_utils
- num/num_locale_utils
- num/num_min_max_utils
- num/num_modulo_utils
- num/num_more_extensions
- num/num_prime_utils
- num/num_range_extensions
- num/num_range_inclusive_extensions
- num/num_round_multiple_extensions
- num/num_safe_division_extensions
- num/num_stats_utils
- num/num_utils
- object/assert_utils
- object/cast_utils
- object/coalesce_utils
- object/copy_with_defaults_utils
- object/default_value_extensions
- object/identity_utils
- object/nullable_more_extensions
- object/pipe_compose_utils
- object/pipe_utils
- object/require_utils
- object/shallow_copy_utils
- parsing/canonicalize_json_utils
- Canonicalization (sort keys, normalize) for JSON-like data — roadmap #639.
- parsing/changelog_section_utils
- Changelog/semantic version section parser — roadmap #431.
- parsing/config_precedence_utils
- Config precedence resolver: defaults → overlay (roadmap #644).
- parsing/csv_dialect_utils
- CSV/TSV dialect detector (roadmap #435).
- parsing/csv_parse_utils
- parsing/email_validation_utils
- parsing/hex_color_utils
- parsing/isbn_utils
- parsing/json_diff_patch_utils
- JSON diff/patch (simple key-level) — roadmap #624.
- parsing/luhn_utils
- parsing/nested_query_parser_utils
- Query string parser with nested keys (a
c) — roadmap #628. - parsing/parse_bool_utils
- parsing/parse_list_utils
- parsing/parser_error_utils
- Rich parser error (line/column, context) — roadmap #647.
- parsing/parsing_more_utils
- parsing/phone_normalize_utils
- parsing/semver_utils
- parsing/size_parse_utils
- parsing/validate_non_empty_utils
- parsing/varint_utils
- Varint encoding/decoding (Protobuf-style) — roadmap #635.
- parsing/version_compare_utils
- parsing/version_parse_utils
- random/common_random
- regex/regex_common_utils
- regex/regex_match_utils
- saropa_dart_utils
- Saropa Dart Utils - Boilerplate reduction tools and human-readable extension methods by Saropa.
- stats/bucketed_aggregate_utils
- Bucketed aggregation (sum/count/avg/min/max per bucket) — roadmap #570.
- stats/confidence_interval_utils
- Confidence interval for mean (normal approximation) — roadmap #562.
- stats/correlation_utils
- Correlation coefficients (Pearson) — roadmap #563.
- stats/data_normalization_utils
- Data normalization (z-score, min-max scaling) — roadmap #576.
- stats/feature_encoding_utils
- Feature scaling/encoding (bucketization, one-hot) — roadmap #589.
- stats/funnel_utils
- Funnel analysis (drop-off between ordered steps) — roadmap #580.
- stats/linear_regression_utils
- Simple linear regression — roadmap #564.
- stats/log_transform_utils
- Log/exp transforms for analytics — roadmap #575.
- stats/metric_rollup_utils
- Metric roll-up (daily → weekly → monthly) — roadmap #587.
- stats/moving_average_utils
- Moving averages: simple, exponential (roadmap #565).
- stats/outlier_mad_utils
- Outlier detection by MAD / Z-score — roadmap #467.
- stats/percentile_rank_utils
- Percentile rank and inverse percentile — roadmap #583.
- stats/quantile_summary_utils
- Quantile summary (percentiles, median, quartiles) — roadmap #572.
- stats/retention_utils
- Retention curves (N-day retention) — roadmap #581.
- stats/robust_stats_utils
- Robust statistics: MAD, trimmed mean (roadmap #561).
- stats/sampling_utils
- Sampling helpers (stratified, systematic) — roadmap #584.
- string/acronym_extract_utils
- Acronym/initialism extractor (e.g. "Saropa Dart Utils (SDU)") — roadmap #429.
- string/apply_patch_utils
- Apply patch (edit script) to string with validation (roadmap #403).
- string/between_result
- string/code_block_extract_utils
- Code block detector/extractor from mixed text (roadmap #422).
- string/did_you_mean_utils
- "Did you mean?" over dictionary (Levenshtein) — roadmap #426.
- string/diff_render_utils
- Diff → colored/HTML/ANSI unified diff renderer (roadmap #402).
- string/duplicate_doc_utils
- Near-duplicate document detector via fingerprints — roadmap #438.
- string/email_quote_strip_utils
- Email reply quote stripper (heuristic) — roadmap #424.
- string/excerpt_utils
- Smart excerpt generator: best snippet around query terms with ellipsis (roadmap #410).
- string/fuzzy_search_utils
- Fuzzy search over list of strings with token + edit distance + ranking (roadmap #406).
- string/glob_utils
- Simple glob matching (**/*.dart style).
- string/html_sanitizer_utils
- HTML sanitizer: allowlist tags/attributes, strip scripts/styles (roadmap #439).
- string/human_name_parser_utils
- Human name parser (first/middle/last/suffix) — roadmap #409.
- string/levenshtein_utils
- Levenshtein (edit) distance and similarity ratio for strings.
- string/markdown_plain_utils
- Markdown to plain text (strip markup, keep structure) — roadmap #420.
- string/markdown_snippet_utils
- Markdown snippet extractor (heading sections, first code block) — roadmap #419.
- string/myers_diff_utils
- Myers diff for strings: minimal edit script (roadmap #401).
- string/ngram_utils
- N-gram generator for strings — character and word n-grams (roadmap #405).
- string/safe_html_excerpt_utils
- Safe HTML excerpt (truncate without breaking tags) — roadmap #440.
- string/search_index_utils
- Simple in-memory search index (term frequency scoring) — roadmap #407.
- string/search_query_parser_utils
- Simplified search query parser (AND/OR, quotes, minus) — roadmap #418.
- string/sensitive_scrub_utils
- Sensitive data scrubber with pluggable patterns (roadmap #425).
- string/slug_dedup_utils
- Slug deduplicator: append incremental suffixes based on taken slugs (roadmap #411).
- string/soundex_utils
- Soundex phonetic encoding for English names.
- string/spelling_key_lookup_utils
- Spelling-tolerant key lookup (canonical → variants) — roadmap #416.
- string/string_analysis_extensions
- string/string_ansi_extensions
- string/string_between_extensions
- string/string_case_acronym_extensions
- string/string_case_extensions
- string/string_character_extensions
- string/string_csv_extensions
- string/string_diacritics_extensions
- string/string_extensions
- string/string_highlight_extensions
- string/string_indent_extensions
- string/string_key_value_extensions
- string/string_line_extensions
- string/string_lower_extensions
- string/string_manipulation_extensions
- string/string_mask_extensions
- string/string_more_extensions
- string/string_nullable_extensions
- string/string_number_extensions
- string/string_punctuation
- string/string_regex_extensions
- string/string_replace_n_extensions
- string/string_search_extensions
- string/string_slug_extensions
- string/string_split_extensions
- string/string_template_extensions
- string/string_text_extensions
- string/string_unicode_extensions
- string/string_utils
- string/string_wildcard_extensions
- string/string_words_extensions
- string/string_wrap_extensions
- string/template_engine_utils
- Simple template engine (conditionals, no eval) — roadmap #413.
- string/text_chunk_utils
- Text segmentation into chunks for indexing (size and sentence boundaries) — roadmap #430.
- string/text_fingerprint_utils
- Text fingerprinting (simhash-style) — roadmap #417.
- string/text_normalize_pipeline_utils
- Text normalization pipeline (composable steps) — roadmap #408.
- string/text_similarity_utils
- Text similarity score (cosine similarity over TF vectors) — roadmap #437.
- string/tokenize_sentences_utils
- Tokenize text into sentences and words (roadmap #404).
- string/url_extract_utils
- URL/link extractor with context (roadmap #423).
- testing/debug_utils
- url/path_extension_utils
- url/path_join_utils
- url/path_more_utils
- url/url_absolute_utils
- url/url_build_utils
- url/url_encode_utils
- URL encode/decode (component vs full). Safe decode. Roadmap #166, #171.
- url/url_extensions
- url/url_query_utils
- uuid/uuid_utils
- uuid/uuid_v4_utils
- validation/cross_field_validation_utils
- Cross-field validation (start < end, one-of required) — roadmap #682.
- validation/data_redaction_utils
- Data redaction policies (masking per field path) — roadmap #692.
- validation/guard_utils
- Defensive coding helpers (guard patterns, invariants) — roadmap #700.
- validation/input_shaping_utils
- Input shaping: clamp/normalize numbers, trim/limit strings — roadmap #696.
- validation/ip_cidr_utils
- IP/CIDR utilities (subnet contains, range checks) — roadmap #686.
- validation/jwt_structure_utils
- JWT structural checks (no crypto) — roadmap #688.
- validation/password_strength_utils
- Password strength estimation (entropy heuristics) — roadmap #687.
- validation/path_validator_utils
- Robust file path validators (prevent traversal, normalize) — roadmap #693.
- validation/pii_detector_utils
- PII detector for free-form text — roadmap #691.
- validation/safe_parse_utils
- Safe parsing wrappers (no-throw, rich error) — roadmap #695.
- validation/safe_temp_name_utils
- Safe temp-file naming (randomized, collision-resistant) — roadmap #694.
- validation/typed_positive_utils
- Typed non-empty/positive wrappers with validation — roadmap #697.
- validation/validation_error_utils
- Normalized error model (code, message, details) for validation (roadmap #683).