Release Notes
Added
- 7 new chat/inference providers. DeepSeek (
DEEPSEEK_API_KEY),
OpenRouter (OPENROUTER_API_KEY), Together AI (TOGETHER_API_KEY),
Fireworks AI (FIREWORKS_API_KEY), Cerebras (CEREBRAS_API_KEY),
SambaNova (SAMBANOVA_API_KEY), and Perplexity (PERPLEXITY_API_KEY).
All are OpenAI-compatible and auto-configured from env vars.
llm/configure, llm/auto-configure, and llm/with-fallback support them.
- 3 new embedding/reranking providers. Nomic (
NOMIC_API_KEY),
Together AI, and Fireworks AI now support embeddings and reranking via
llm/configure-embeddings and llm/auto-configure. New RerankDialect
variants for each provider's wire format.
:int type validation in llm/extract. The :int type tag is now
properly validated — accepts integers and whole-number floats, rejects
other types.[:type] list syntax in llm/extract schemas. A field spec like
{:authors [:string]} is now sent to the model as "array of string" and
validated as a list where each element matches the inner type.
Fixed
llm/configure-embeddings now wires reranking. Previously, configuring
embeddings via llm/configure-embeddings for Jina, Voyage, or Cohere did
not call .with_rerank() or set_rerank_provider(), so llm/rerank would
fail with "does not support reranking". All three providers now correctly
set up reranking when configured via this path.llm/extract and llm/classify are now sandbox-gated with Caps::LLM.
Previously only llm/extract-from-image was gated. Text-based extraction
and classification made LLM API calls even when the sandbox denied Caps::LLM.- Dynamic workflows.
defworkflow / phase / step / checkpoint /
parallel / pipeline — a journaled, resumable agentic-workflow runtime.
Define multi-phase LLM workflows as ordinary Sema code; the runtime journals
every event to a frozen JSONL run directory (.sema/runs/<run-id>/), enforces
budget caps (:tokens / :usd), and supports --resume via content-keyed
memo sidecars. sema workflow run / view / index / check CLI commands.
A web viewer (sema workflow view) renders live runs with a SQLite cross-run
index. sema workflow check statically validates workflow files without
evaluating them — catches arity traps and layout issues before a run.
Doc entries for all workflow builtins are available in LSP hover/completion.
Feature page at /feature/workflows.
:stack-trace on caught error maps. The VM now captures the call stack
at error time and serializes it as a :stack-trace field on caught error
maps — a list of {:name :file :line :col} frame maps, innermost first.
For inline opcodes (+, -, car, etc.), a synthetic intrinsic frame is
synthesized by decoding the opcode at the failing PC. TCO-bounded: tail
calls reuse frames, so the trace stays small even for deep recursion.
Source spans are now threaded through the main eval path
(run_exprs_on_vm) via compile_program_with_spans_and_natives, so
function frames carry :line and :col from the original source.
Fixed
pretty_print no longer double-serializes values. pretty_print called
format!("{value}") to check if the compact form fit, then pp_value repeated
the same format! at indent=0 when it didn't — walking and stringifying the
entire tree twice. The redundant check is removed; pp_value handles it
directly. Affects every REPL result, DAP variable inspection, and WASM
playground output.- Runtime
/ now matches the constant folder for large integers. The
optimizer used exact i64 division while the runtime converted to f64
first, causing (/ 9007199254740993 1) to return different results depending
on whether the operands were compile-time constants. A two-integer fast path
in the runtime / uses exact i64 division when a % b == 0, falling back
to f64 for non-whole results. +, -, * were unaffected (both paths
already used i64).
ValueViewRef — zero-refcount trait impls. PartialEq, Hash, Ord,
Display, and pp_value previously used view() which calls
Rc::increment_strong_count + Rc::from_raw (and a matching decrement on
drop) for every heap-typed Value comparison. A new ValueViewRef<'a> enum
and view_ref() method use borrow_ref (raw pointer deref) instead,
eliminating refcount mutations on every ==, cmp(), hash(), and
format!(). Micro-benchmarked 40–60% faster on eq/cmp for strings,
lists, and maps; 39.9% faster total across the benchmark suite.- VM arithmetic and comparison functions use
view_ref(). vm_add,
vm_sub, vm_mul, vm_div, vm_eq, vm_lt (the handlers for every
ADD/SUB/MUL/DIV/EQ/LT/GT/LE/GE opcode) and the stdlib
comparison.rs, arithmetic.rs, predicates.rs, math.rs, map.rs, and
list.rs modules were migrated from view() to view_ref(), eliminating
refcount churn on numeric and collection operations.
filter no longer double-clones passing items. Each item that passed the
predicate was cloned twice (once for the predicate call, once for the result
vector). Now cloned once and reused for both.- Optimizer
extend_shadowed avoids allocation when nothing is shadowed.
The function previously called current.to_vec() on every let/let*/
letrec/lambda/do/try form, even when none of the new names were
foldable builtins (the common case). Now returns Cow::Borrowed when no
foldable names are added, avoiding the allocation entirely.
- DAP
serde_json::to_string().unwrap() replaced with error handling. Four
sites in the DAP server (event send, initialized event, send_response,
send_error) now log serialization errors to stderr instead of panicking.
A malformed debug value would have crashed the entire debug session.
- DAP
decode_percent off-by-one fixed. The check i + 2 < bytes.len()
required at least one byte after the two hex digits, so a percent-encoded
sequence at the very end of a file URI (e.g. file%20 for a trailing space)
was not decoded. Fixed to i + 3 <= bytes.len().
- DAP debug query boilerplate extracted into helpers. The
sync_channel(1) + send + spawn_blocking + recv pattern duplicated
6× across setBreakpoints, stackTrace, scopes, variables, evaluate,
and setVariable is now send_cmd_and_recv / send_cmd_and_recv_result.
- Formatter
token_text returns Cow<str> and token_width avoids
allocation. token_text was -> String, allocating on every call including
in measure_width where only .len() was needed. Now -> Cow<'_, str>
(symbols — the most common token — return Cow::Borrowed), with a separate
token_width function that computes the width without allocating.
- Formatter
format_top_level O(n²) → single-pass. When alignment failed
for a group of N consecutive defines, the code formatted only the first and
re-scanned the remaining N-1 on the next iteration. Now formats the entire
group in one pass and advances past it.
Span::contains and Span::contains_pos consolidated. Three
near-identical span containment functions duplicated across
sema-lsp/helpers.rs and sema-lsp/scope.rs are now methods on Span in
sema-core, available to all crates.
Performance
builtin_index() cached with OnceLock. The ~11K-line JSON doc index
was deserialized from scratch on every ,apropos REPL command. Now parsed
once and cached; subsequent calls return a &'static DocIndex reference.BuiltinDocs::load() shares entries via Rc<DocEntry>. Each DocEntry
(with full markdown body, params, examples) was cloned once per alias. Now
all names for the same entry share a single Rc<DocEntry>, eliminating
hundreds of string clones at LSP startup.expand_query O(n²) → O(n) dedup. The synonym expansion in MCP
docs_search used a linear scan per token for de-duplication. Now uses a
HashSet.
Install sema-lang 1.28.0
Install prebuilt binaries via shell script
curl --proto '=https' --tlsv1.2 -LsSf https://github.com/HelgeSverre/sema/releases/download/v1.28.0/sema-lang-installer.sh | sh
Install prebuilt binaries via powershell script
powershell -ExecutionPolicy Bypass -c "irm https://github.com/HelgeSverre/sema/releases/download/v1.28.0/sema-lang-installer.ps1 | iex"
Install prebuilt binaries via Homebrew
brew install helgesverre/tap/sema-lang
Download sema-lang 1.28.0
