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What's New — Per Version

Each version of Frankie ships a runnable whats_new_vX.fk example file that demonstrates every new feature introduced in that release. Run any of them with:

frankiec run examples/whats_new_v114.fk

v1.14 — whats_new_v114.fk

Theme: Frankie for real web apps — concurrency, templates, signed cookies, middleware, static files, and two language upgrades that make working with data cleaner everywhere.

Feature Summary
spawn { } Run a block in a background thread — response goes out immediately, work continues behind the scenes
timeout(n) { } Kill a block that exceeds n seconds — raises TimeoutError, wrap in begin/rescue for graceful fallback
Async routes app.get_async / app.post_async etc. — non-blocking handlers, use await inside for slow I/O
Middleware stack app.use do |req, next_fn| — chain auth, logging, and rate-limiting; call next_fn.(req) to continue or return early to short-circuit
Static file serving app.static("./public") — serve a directory at /; app.static("./assets", "/static") for a URL prefix
frankietemplate Mustache-compatible template stitch — {{ var }}, {{{ raw }}}, {{# section }}, {{^ inverted }}, {{> partial }}, {{! comment }}
frankiecookie HMAC-signed cookies via Python's hmac stdlib — set_signed_cookie / get_signed_cookie returns nil if tampered
Hash destructuring {name, age} = user — pull symbol keys directly into variables; missing keys become nil
Shape pattern matching case user when {role: "admin"} — when now accepts hash literals, matches on subset of keysfrankiec new scaffold
Global stitch install install.py now correctly copies all stitches to ~/.frankie/stitches/ and lists each file installed
page_links docs Full web pagination example added — paginate + page_slice + page_links + frankietemplate working together

v1.13.1 — whats_new_v1131.fk

Theme: Gap closers — no new syntax, everything real programs needed and didn't have.

Feature Summary
frankiestring v2 Rewritten stitch: pad_left, pad_right, truncate, slugify, word_wrap, indent_lines — replaces clunky lfill/rfill API
Vector .sum do \|x\| Block form now works — projected sum without a two-step .map + sum
Vector .flat_map do \|x\| Multi-line block bodies now parse correctly
assert_approx_eq(a, b, delta, msg) Float comparison in tests with configurable delta (default 0.001)
run_tests() Now a public stdlib function — callable from any .fk file, not just frankiec test
session(req, resp) Cookie-backed session hash — read, mutate, .save(). Zero server state, single JSON cookie _fk_session
frankiec fmt blank lines Intentional blank lines between statement groups inside function bodies now preserved
frankiec fmt multi-line threshold Hashes/vectors whose inline form exceeds 60 chars auto-expand to one element per line
frankiec fmt idempotency Running fmt --write twice now produces identical output — safe for pre-commit hooks and CI
Heredoc in do...end blocks Fixed lexer bug — heredocs now work anywhere a string expression is valid
Hash.each do \|k, v\| Two-parameter block iteration confirmed and end-to-end tested
Symbol key round-trip in fmt {host: "x"} no longer becomes {"host": "x"} after formatting

v1.13 — whats_new_v113.fk

Theme: Stitches — a zero-dependency, zero-registry package system.

Feature Summary
stitch "name" keyword Load a package by name — resolves from ./stitches/ then ~/.frankie/stitches/
frankieforms Form field validation — required, min_length, max_length, email, numeric, alpha, matches_pattern
frankietable ASCII table rendering from a vector of hashes — table(rows) / table(rows, cols)
frankiecolor ANSI color helpers — red, green, yellow, bold, success, error, warn, info, colorize, strip_color
frankiepager Pagination math — paginate(opts), page_slice(items, page, per_page), page_links(pager, url_template)
frankieconfig Layered config loading: defaults → JSON file → env vars → overrides, with type coercion
frankiestring String utilities stitch (v1, superseded by v2 in v1.13.1)
? in function names def even?(n) now works — ? compiled transparently to _q in generated Python

v1.12 — whats_new_v112.fk

Theme: Filling stdlib gaps, fixing error handling, tooling polish.

Feature Summary
String .gsub with block Transform each regex match via a block — "hello".gsub("[aeiou]") do \|m\| m.upcase end
Hash .map_hash Transform a hash into a new hash — block returns [new_key, new_value]
round(x, n) Round to n decimal places — round(3.14159, 2) → 3.14
Vector .product(other) Cartesian product — [1,2].product([3,4]) → [[1,3],[1,4],[2,3],[2,4]]
String .chars Promoted to first-class documented method — chains into iterators
each_with_object + Hash Hash accumulator now explicitly documented and tested
assert_match / assert_nil Two new test runner assertions
rescue FileNotFoundError file_read and file_lines now raise the correct type
frankiec watch Re-run on save — frankiec watch main.fk
frankiec repl --no-banner Headless REPL for scripts and pipes
Friendlier runtime errors Type errors now say "Integer and String", not Python internals

v1.11 — whats_new_v111.fk (in docs/13_v111_features.md)

Theme: Ergonomics — removing paper cuts, making the common case obvious.

Feature Summary
Implicit return Last expression in a function is returned automatically
Inline if expression grade = if score >= 90 then "A" else "B" end
String .replace(old, new) The method new users always reach for first
String .format(hash) "Hello, {name}!".format({name: "Alice"})
.zip_with do \|a, b\| Pair-wise transform two vectors in one pass
Multiple return values lo, hi = min_max(data) — destructuring from functions
frankiec check boxed errors Parse errors now use the same box as runtime errors
REPL multi-line history ↑ recalls a full def...end block
frankiec fmt heredoc support Heredoc bodies preserved verbatim during formatting
String .delete(chars) "hello".delete("l") → "heo" — documented

v1.10 — whats_new_v110.fk

Theme: Expressiveness — more ways to write less.

Feature Summary
String * n / Vector * n "ha" * 3 → "hahaha" · [0] * 5 → [0,0,0,0,0]
Heredoc <<~TEXT Multi-line strings with auto indent-stripping and interpolation
times() standalone times(5) do \|i\| alongside 5.times do
flatten(depth) Flatten exactly n levels — flatten(1) vs deep flatten
map_with_index v.map_with_index do \|x, i\|
pp — pretty print pp({host: "localhost", port: 3000})
encode / decode "hi".encode → [104, 105] · [104, 105].decode → "hi"
Exit codes exit(0) / exit(1) — propagated to shell
--help flag frankiec run --help etc.

v1.9 — whats_new_v19.fk

Theme: Safety and tooling.

Feature Summary
Hash .dig config.dig("db", "host") — safe nested access, returns nil
zip() standalone zip([1,2,3], ["a","b","c"]) → [[1,"a"],[2,"b"],[3,"c"]]
Record types record Point(x, y) — named data objects built on Hash
frankiec fmt AST-based auto-formatter with --write and --check
frankiec docs Extract ## doc-comments to Markdown
REPL readline + history Arrow keys, Ctrl+R, tab completion, persistent ~/.frankie_history
.env auto-loading .env in the project root is loaded automatically at startup

v1.8 — whats_new_v18.fk

Theme: Functional programming and collection power.

Feature Summary
Lambdas ->(x) { x * 2 } — storable, passable first-class functions
Hash merge \| h1 \| h2 — right wins on conflict, chains naturally
group_by Bucket elements into a hash of arrays by block result
each_slice(n) Iterate in non-overlapping chunks
each_cons(n) Iterate with a sliding window

v1.7 — whats_new_v17.fk

Theme: Safety and real-world utility.

Feature Summary
Nil safety &. name&.upcase returns nil instead of crashing
template(str, hash) {{key}} placeholder substitution
File system ops file_mkdir, dir_exists, dir_list, file_copy, file_rename
assert_raises_typed Test that a specific error type is raised

v1.6 — whats_new_v16.fk

Theme: Control flow completeness.

Feature Summary
Compound assignment +=, -=, *=, /=, //=, **=, %=
Typed rescue rescue ZeroDivisionError e — catch specific error types
.find / .detect First element matching a block condition
frankiec test Built-in test runner

v1.5 — whats_new_v15.fk

Theme: Loop control, randomness, and collection utilities.

Feature Summary
next Skip to next iteration — like continue
break Exit a loop early
break value Exit with a result — result = loop.break n * 10
Constants UPPER_CASE — warn on reassignment
rand_int, rand_float Random number functions
shuffle, sample Random collection operations
sleep(n) Pause execution
sort_by Sort by computed key
min_by, max_by, sum_by Aggregate by key
unzip Split vector of pairs into two vectors

v1.4 — whats_new_v14.fk

Theme: Built-in web server.

Feature Summary
Web server web_app() — Sinatra-style routing
Route definitions .get, .post, .put, .delete, .patch
Path parameters /users/:id → req.params["id"]
Query parameters req.query["page"]
JSON body req.json — auto-parsed
Before/after filters app.before do, app.after do
Response helpers html_response, json_response, redirect, halt

v1.3 — whats_new_v13.fk

Theme: External data and project structure.

Feature Summary
JSON json_read, json_write, json_parse, json_dump
CSV csv_read, csv_write, csv_parse, csv_dump
DateTime now(), today(), date_parse(), date_from()
HTTP client http_get, http_post, http_put, http_delete
frankiec new Project scaffolding

v1.2 (no whats_new file)

Theme: Database and multi-file programs.

Feature Summary
SQLite built-in db_open, db.query, db.insert, db.exec, transactions
require Load other .fk files — each loaded at most once

v1.1 — whats_new_v11.fk

Theme: Collection power.

Feature Summary
select / reject Filter a vector by a condition
reduce / inject Fold a vector into a single value
any? / all? / none? Boolean tests across a collection
each_with_object Iterate with a shared accumulator
take, drop, chunk, tally, compact Collection utilities
flat_map, zip Flattening and pairing
case / when Pattern matching on values
Destructuring assignment a, b, c = [1, 2, 3]
New string methods .chomp, .chop, .center, .ljust, .rjust, .squeeze, .tr
count with block Count elements matching a condition

v1.0 (initial release)

The foundation: variables, strings with #{} interpolation, integers, floats, booleans, nil, vectors, hashes, if/elsif/else/unless, while/until/for, functions with default params, begin/rescue/ensure, raise, regex (matches, match_all, sub, gsub, =~), file I/O (file_read, file_write), R-style statistics (mean, stdev, median, sum), vectorised arithmetic, the pipe operator |>, seq, linspace, the REPL, and frankiec run/build/check.