--- url: 'https://sema-lang.com/docs/stdlib.md' --- # Standard Library Sema ships with a **comprehensive standard library** of built-in functions across many modules, covering everything from string manipulation and file I/O to HTTP requests, regex, and cryptographic hashing. ## Naming Conventions Sema's stdlib follows consistent naming patterns: | Pattern | Convention | Example | | ----------------- | -------------------- | -------------------------------------- | | `module/function` | Slash-namespaced | `string/trim`, `file/read`, `math/gcd` | | `legacy-name` | Scheme compat aliases | `string-append` → `string/append` | | `type->type` | Arrow conversions | `string/to-symbol`, `list->vector` | | `predicate?` | Predicate suffix | `null?`, `list?`, `even?` | ### Naming aliases Several functions are registered under both a legacy (Scheme-style) name and a canonical slash-namespaced or `predicate?` name (Decision #24). Both forms are kept for backward compatibility; new code should prefer the canonical form on the right. | Legacy name | Canonical alias | | --------------------- | ---------------------- | | `any` | `any?` | | `every` | `every?` | | `time-ms` | `time/now-ms` | | `hash-map` | `map/new` | | `promise-forced?` | `async/forced?` | | `tools->routes` | `route/from-tools` | | `make-bytevector` | `bytevector/make` (also `bytevector/new`) | | `bytevector-length` | `bytevector/length` | | `bytevector-u8-ref` | `bytevector/u8-ref` (also `bytevector/ref`) | | `bytevector-u8-set!` | `bytevector/u8-set!` (also `bytevector/set!`) | | `bytevector-copy` | `bytevector/copy` | | `bytevector-append` | `bytevector/append` | | `bytevector->list` | `bytevector/to-list` | | `list->bytevector` | `bytevector/from-list` (also `list/to-bytevector`) | Predicates (`bytevector?` etc.) and the bare `bytevector` varargs constructor keep their short canonical names — predicates always stay un-namespaced. ## Quick Reference ### [Math & Arithmetic](./math) | Function | Description | | ------------------------------------------------------------------------------ | ------------------------- | | `+`, `-`, `*`, `/`, `mod` | Basic arithmetic | | `<`, `>`, `<=`, `>=`, `=` | Comparison | | `abs`, `min`, `max`, `pow`, `sqrt`, `log` | Numeric utilities | | `floor`, `ceil`, `round`, `truncate` | Rounding | | `sin`, `cos`, `math/tan` | Trigonometry | | `math/asin`, `math/acos`, `math/atan`, `math/atan2` | Inverse trig | | `math/sinh`, `math/cosh`, `math/tanh` | Hyperbolic | | `math/exp`, `math/log10`, `math/log2` | Exponential & logarithmic | | `math/gcd`, `math/lcm`, `math/quotient`, `math/remainder` | Integer math | | `math/random`, `math/random-int` | Random numbers | | `math/clamp`, `math/sign`, `math/lerp`, `math/map-range` | Interpolation & clamping | | `math/degrees->radians`, `math/radians->degrees` | Angle conversion | | `even?`, `odd?`, `positive?`, `negative?`, `zero?` | Numeric predicates | | `math/nan?`, `math/infinite?` | Float predicates | | `pi`, `e`, `math/infinity`, `math/nan` | Constants | | `bit/and`, `bit/or`, `bit/xor`, `bit/not`, `bit/shift-left`, `bit/shift-right` | Bitwise operations | ### [Strings & Characters](./strings) | Function | Description | | ----------------------------------------------------------------------------------- | ------------------------- | | `string/append`, `string/length`, `string/ref`, `string/slice` | Core string ops | | `str`, `format` | Conversion & formatting | | `string/split`, `string/join`, `string/trim` | Split, join, trim | | `string/upper`, `string/lower`, `string/capitalize`, `string/title-case` | Case conversion | | `string/contains?`, `string/starts-with?`, `string/ends-with?` | Search predicates | | `string/replace`, `string/index-of`, `string/last-index-of`, `string/reverse` | Manipulation | | `string/chars`, `string/repeat`, `string/pad-left`, `string/pad-right` | Utilities | | `string/map`, `string/number?`, `string/empty?` | Higher-order & predicates | | `string/after`, `string/before`, `string/between`, `string/take` | Slicing & extraction | | `string/chop-start`, `string/chop-end`, `string/ensure-start`, `string/ensure-end` | Prefix & suffix | | `string/wrap`, `string/unwrap`, `string/remove` | Wrapping & removal | | `string/replace-first`, `string/replace-last` | Targeted replacement | | `string/snake-case`, `string/kebab-case`, `string/camel-case`, `string/pascal-case` | Case conversion | | `string/headline`, `string/words` | Headline & word splitting | | `char/to-integer`, `integer/to-char`, `char/alphabetic?`, ... | Character operations | | `string/to-number`, `number/to-string`, `string/to-symbol`, ... | Type conversions | ### [Lists](./lists) | Function | Description | | ----------------------------------------------------------------------- | ----------------------------- | | `list`, `cons`, `car`, `cdr`, `first`, `rest` | Construction & access | | `cadr`, `caddr`, `last`, `nth` | Positional access | | `length`, `append`, `reverse`, `range` | Basic operations | | `map`, `filter`, `foldl`, `foldr`, `reduce`, `flat-map` | Higher-order functions | | `sort`, `sort-by`, `apply`, `for-each` | Ordering & application | | `take`, `drop`, `flatten`, `flatten-deep`, `zip`, `partition` | Sublists | | `member`, `any`, `every`, `list/index-of`, `list/unique`, `list/dedupe` | Searching | | `list/group-by`, `list/interleave`, `list/chunk`, `frequencies` | Grouping | | `list/sum`, `list/min`, `list/max` | Aggregation | | `list/shuffle`, `list/pick` | Random | | `list/repeat`, `make-list`, `iota` | Construction | | `list/split-at`, `list/take-while`, `list/drop-while` | Splitting | | `assoc`, `assq`, `assv` | Association lists | | `interpose` | Interleaving | | `list/reject`, `list/find`, `list/sole` | Filtering & searching | | `list/pluck`, `list/key-by` | Map extraction | | `list/avg`, `list/median`, `list/mode` | Statistics | | `list/diff`, `list/intersect`, `list/duplicates` | Set operations | | `list/sliding`, `list/page`, `list/cross-join` | Windowing & pagination | | `list/pad`, `list/join`, `list/times` | Padding, joining & generation | | `tap` | Utility | ### [Vectors](./vectors) | Function | Description | | ------------------------------ | --------------- | | `vector` | Create a vector | | `vector->list`, `list->vector` | Conversion | ### [Maps & HashMaps](./maps) | Function | Description | | -------------------------------------------------- | ---------------------------- | | `map/new`, `get`, `assoc`, `dissoc`, `merge` | Core map ops | | `keys`, `vals`, `contains?`, `count` | Inspection | | `map/entries`, `map/from-entries` | Entry conversion | | `map/map-vals`, `map/map-keys`, `map/filter` | Higher-order | | `map/select-keys`, `map/update` | Selection & update | | `map/sort-keys`, `map/except`, `map/zip` | Sorting, exclusion & zipping | | `hashmap/new`, `hashmap/get`, `hashmap/assoc`, ... | HashMap operations | ### [Predicates & Type Checking](./predicates) | Function | Description | | ----------------------------------------------------------------- | --------------------- | | `null?`, `nil?`, `empty?`, `list?`, `pair?` | Collection predicates | | `number?`, `integer?`, `float?`, `string?`, `symbol?`, `keyword?` | Type predicates | | `char?`, `record?`, `bytevector?`, `bool?`, `fn?` | More type predicates | | `map?`, `vector?` | Container predicates | | `promise?`, `promise-forced?` | Promise predicates | | `eq?`, `=`, `zero?`, `even?`, `odd?`, `positive?`, `negative?` | Equality & numeric | | `prompt?`, `message?`, `conversation?`, `tool?`, `agent?` | LLM type predicates | ### [File I/O & Paths](./file-io) | Function | Description | | ------------------------------------------------------------------------------------------------------------- | ---------------------------- | | `display`, `println`, `pprint`, `print`, `io/print-error`, `io/println-error`, `newline`, `io/read-line`, `io/read-stdin`, `io/eof?`, `io/flush` | Console I/O | | `file/read`, `file/write`, `file/append` | File read/write | | `file/read-bytes`, `file/write-bytes` | Binary file I/O | | `file/read-lines`, `file/write-lines` | Line-based I/O | | `file/for-each-line`, `file/fold-lines`, `file/fold-lines-bytes` | Streaming line I/O | | `file/delete`, `file/rename`, `file/copy` | File management | | `file/exists?`, `file/is-file?`, `file/is-directory?`, `file/is-symlink?` | File predicates | | `file/list`, `file/mkdir`, `file/info` | Directory operations | | `file/glob` | File globbing | | `path/join`, `path/dirname`, `path/basename`, `path/extension`, `path/absolute` | Path manipulation | | `path/ext`, `path/stem`, `path/dir`, `path/filename`, `path/absolute?` | Path predicates & components | ### [PDF Processing](./pdf) | Function | Description | | ------------------------ | ----------------------------------------------------- | | `pdf/extract-text` | Extract all text from a PDF | | `pdf/extract-text-pages` | Extract text per page (returns list) | | `pdf/page-count` | Get number of pages | | `pdf/metadata` | Get metadata map (`:title`, `:author`, `:pages`, ...) | ### [HTTP & JSON](./http-json) | Function | Description | | ------------------------------------------------------------------ | ------------------ | | `http/get`, `http/post`, `http/put`, `http/delete`, `http/request` | HTTP methods | | `json/encode`, `json/encode-pretty`, `json/decode` | JSON serialization | ### [Web Server](./web-server) | Function | Description | | -------------------------------------------------------------------------------- | ---------------------- | | `http/serve` | Start an HTTP server | | `http/router` | Data-driven routing | | `http/ok`, `http/created`, `http/no-content`, `http/not-found`, `http/error` | JSON response helpers | | `http/redirect` | HTTP redirect | | `http/html`, `http/text` | Content-type responses | | `http/file` | Serve a file from disk | | `http/stream` | SSE streaming | | `http/websocket` | WebSocket connections | ### [Regex](./regex) | Function | Description | | --------------------------------------------------- | ----------------------- | | `regex/match?`, `regex/match`, `regex/find-all` | Matching | | `regex/replace`, `regex/replace-all`, `regex/split` | Replacement & splitting | ### [CSV, Crypto & Encoding](./csv) | Function | Description | | --------------------------------------------- | --------------- | | `csv/parse`, `csv/parse-maps`, `csv/encode` | CSV operations | | `uuid/v4` | UUID generation | | `base64/encode`, `base64/decode` | Base64 encoding | | `base64/encode-bytes`, `base64/decode-bytes` | Binary Base64 | | `hash/sha256`, `hash/md5`, `hash/hmac-sha256` | Hashing | ### [Date & Time](./datetime) | Function | Description | | --------------------------- | -------------------- | | `time/now`, `time-ms` | Current time | | `time/format`, `time/parse` | Formatting & parsing | | `time/date-parts` | Date decomposition | | `time/add`, `time/diff` | Arithmetic | | `sleep` | Delay execution | ### [System](./system) | Function | Description | | ----------------------------------------------------------- | --------------------- | | `env`, `sys/env-all`, `sys/set-env` | Environment variables | | `sys/args`, `sys/cwd`, `sys/platform`, `sys/os`, `sys/arch` | System info | | `sys/pid`, `sys/tty`, `sys/which`, `sys/elapsed` | Process info | | `sys/interactive?`, `sys/hostname`, `sys/user` | Session info | | `sys/home-dir`, `sys/temp-dir` | Directory paths | | `sys/term-size` | Terminal size (Unix) | | `sys/on-signal`, `sys/check-signals` | Signal hooks (Unix) | | `shell` | Run shell commands | | `exit` | Exit process | ### [Serial Ports](./serial) | Function | Description | | ---------------------------------------------------------- | ---------------------------------------- | | `serial/list` | List available device paths | | `serial/open`, `serial/close` | Open/close a port (returns int handle) | | `serial/write`, `serial/read-line` | Raw I/O | | `serial/send` | Write line + read JSON response | ### [Bytevectors](./bytevectors) | Function | Description | | -------------------------------------------------------------- | ----------------- | | `bytevector`, `bytevector/new` | Construction | | `bytevector/length`, `bytevector/ref`, `bytevector/set!` | Access & mutation | | `bytevector/copy`, `bytevector/append` | Copy & append | | `bytevector/to-list`, `list/to-bytevector` | List conversion | | `utf8/to-string`, `string/to-utf8` | String conversion | | `bytes/length`, `bytes/ref`, `bytes/find`, `bytes/slice` | Byte-oriented ops (hot loops) | | `bytes/->string`, `bytes/parse-int10` | Byte decoding & parsing | ### [Streams](./streams) | Function | Description | | --------------------------------------------------------------------- | ------------------------ | | `stream/from-string`, `stream/from-bytes`, `stream/byte-buffer` | In-memory streams | | `stream/open-input`, `stream/open-output` | File streams | | `stream/read`, `stream/read-byte`, `stream/read-line`, `stream/read-all` | Reading | | `stream/write`, `stream/write-byte`, `stream/write-string` | Writing | | `stream/close`, `stream/flush`, `stream/copy` | Control | | `stream?`, `stream/readable?`, `stream/writable?`, `stream/available?` | Predicates | | `stream/type`, `stream/to-bytes`, `stream/to-string` | Introspection & extraction | | `*stdin*`, `*stdout*`, `*stderr*` | Standard I/O globals | | `with-stream` | Resource management macro | ### [Concurrency](./concurrency) | Function | Description | | --------------------------------------------------------------------- | ------------------------ | | `async/spawn`, `async/await`, `async/all`, `async/race` | Async task management | | `async/resolved`, `async/rejected` | Pre-settled promises | | `async/run`, `async/sleep`, `async/timeout` | Scheduler control & deadlines | | `async/cancel`, `async/cancelled?` | Cancellation | | `async/promise?`, `async/resolved?`, `async/rejected?`, `async/pending?` | Promise predicates | | `channel/new`, `channel/send`, `channel/recv`, `channel/try-recv` | Channel operations | | `channel/close` | Channel lifecycle | | `channel?`, `channel/closed?`, `channel/empty?`, `channel/full?`, `channel/count` | Channel predicates | ### [Records](./records) | Function | Description | | -------------------- | -------------------- | | `define-record-type` | Define a record type | | `record?` | Record predicate | | `type` | Get record type tag | ### [Terminal Styling](./terminal) | Function | Description | | ---------------------------------------------------------------- | ----------------------------------- | | `term/bold`, `term/red`, `term/green`, ... | Individual style functions | | `term/style` | Apply multiple styles with keywords | | `term/rgb` | 24-bit true color | | `term/strip` | Remove ANSI escape codes | | `term/spinner-start`, `term/spinner-stop`, `term/spinner-update` | Animated spinners | | `io/tty-raw!`, `io/tty-restore!` | Raw-mode TTY (Unix) | | `io/read-key`, `io/read-key-timeout` | Per-keystroke input (Unix) | ### [Text Processing](./text-processing) | Function | Description | | ------------------------------------------------------------------------- | ------------------------------------------ | | `text/chunk`, `text/chunk-by-separator`, `text/split-sentences` | Text chunking | | `text/clean-whitespace`, `text/strip-html` | Text cleaning | | `text/truncate`, `text/word-count`, `text/trim-indent` | Text utilities | | `text/excerpt`, `text/normalize-newlines` | Excerpt extraction & newline normalization | | `prompt/template`, `prompt/render` | Prompt templates | | `document/create`, `document/text`, `document/metadata`, `document/chunk` | Document metadata | ### [SQLite](./sqlite) | Function | Description | | -------------------------------- | ------------------------------ | | `db/open`, `db/open-memory` | Open file or in-memory database | | `db/exec`, `db/exec-batch` | Execute statements | | `db/query`, `db/query-one` | Query rows as maps | | `db/last-insert-id` | Last inserted rowid | | `db/tables` | List tables | | `db/close` | Close connection | ### [Typed Arrays](./typed-arrays) | Function | Description | | --------------------------------------------------------- | ---------------------- | | `f64-array`, `i64-array` | Create from values | | `f64-array/make`, `i64-array/make` | Create with fill | | `f64-array/range`, `i64-array/range` | Create from range | | `f64-array/from-list`, `i64-array/from-list` | Convert from list | | `f64-array/ref`, `i64-array/ref` | Index access | | `f64-array/set!`, `i64-array/set!` | Set element (CoW) | | `f64-array/length`, `i64-array/length` | Length | | `f64-array/sum`, `i64-array/sum` | Fast sum | | `f64-array/dot` | Dot product | | `f64-array/map`, `i64-array/map` | Map over elements | | `f64-array/fold`, `i64-array/fold` | Fold over elements | | `f64-array?`, `i64-array?` | Type predicates | ### [Mutable Containers](./mutable) | Function | Description | | ----------------------------------------------------------- | ---------------------------------- | | `mutable-array/new` | Create (empty, capacity, or n×fill) | | `mutable-array/push!`, `mutable-array/set!` | In-place update (return the array) | | `mutable-array/get`, `mutable-array/length` | Access | | `mutable-array/->vector` | Freeze to an immutable vector | | `mutable-cell/new`, `mutable-cell/get`, `mutable-cell/set!` | Single mutable slot | ### [Context](./context) | Function | Description | | ----------------------------------------------------------------- | ---------------------------------------- | | `context/set`, `context/get`, `context/has?` | Core key-value context | | `context/remove`, `context/pull`, `context/all` | Retrieval & cleanup | | `context/merge`, `context/clear` | Bulk operations | | `context/with` | Scoped overrides (auto-restores on exit) | | `context/push`, `context/stack`, `context/pop` | Named stacks | | `context/set-hidden`, `context/get-hidden`, `context/has-hidden?` | Hidden (non-logged) context | ### [Key-Value Store](./kv-store) | Function | Description | | ------------------------------- | ------------------------------ | | `kv/open`, `kv/close` | Open/close a JSON-backed store | | `kv/get`, `kv/set`, `kv/delete` | CRUD operations | | `kv/keys` | List all keys | ### [TOML](./toml) | Function | Description | | ------------------------------- | -------------------- | | `toml/decode` | Decode TOML to Sema | | `toml/encode` | Encode Sema to TOML | ### [Playground & WASM](./playground) | Function | Description | | --------------------- | ------------------------------------------------------ | | `web/user-agent` | Browser user agent string (WASM only) | | `web/user-agent-data` | Structured browser info map (Chromium only, WASM only) |