Implementation status (TBD)

Most of Pyrope is implemented in LiveHD and exercised by its test suite. This page lists the documented features that are not implemented yet; each is also marked "TBD" where it is described. A feature on this list may parse (lhd elaborate is permissive) but does not lower to working hardware.

Each feature has a matching task page (with a failing example) in the LiveHD repo under todo/.

Feature	Documented in	Task	Notes
fluid lambdas, valid/retry/fire elastic handshakes	Fluid Blocks	2f-fluid	syntax parses; no lowering
Temporal library: past(x, n), rose, fell, stable, changed, eventually(x, w), always(x, w)	Extended Verification	2f-temporal	positional args only — there is no f[N](x) bracket form. The pipelining past[N](x) DOES work (design body only) and is a different operator. No edge attributes: .[rising]/.[falling]/.[changed]/.[stable] are not recognized. lhd formal verify must reject these calls with an explicit "not implemented" diagnostic
Testbench extras: string sigref (arbitrary-path), force/release, cpp(...) external models, unbounded tick { }	Extended Verification	2f-testbench	the instance/step/poke-peek model + if/continue waiting + if-block monitors run via lhd sim; string peek/poke work; waitfor/spawn/join/cancel are dropped (replaced by that idiom)
regref (register reference through the instance hierarchy)	Verification, Type system	2f-testbench	not needed for assert/assume: verification code reaches signals through the ordinary instance hierarchy
Statements rejected inside a test block: for loops, .[rand]/.[crand], past[N], positional instantiation-by-call	Testing	2f-test_syntax	dotted names, runtime (...) params, tick/step/break/continue, and field + string poke/peek all work
Standard library (import("prp"))	Standard Library	2f-stdlib	wish-list chapter
macro= memory-compiler binding	Memories	2f-macro
cover, covercase, in-language lec()/lec_valid()	Assertions	2f-verif_extras	assert/cassert/assume/assert_always work; cover does NOT exist in any context
.[rand] / .[crand] random generation	Random	2f-verif_extras	rejected in test blocks and design bodies; survives only where it constant-folds
assert.[failed] (read/clear the accumulated failure flag in a test)	Test	2f-verif_extras
always_assert / always_cassert / always_assume / always_cover / always_covercase; valid-based (.[valid]) gating of checks	Reset and verification	2f-verif_extras	the implemented spelling is assert_always; no valid-based gating exists
Generics: body references of a generic name (T(a), mut tmp:T, a + N, F(v=a)), constant/lambda-valued generics, defaults <T, N=4>, named <T=…> bindings	Functions	3g	signature :T binding works: explicit f<u8>(…), inference, mod/pipe specialization
Input default values (comb f(in1:u4, in2=3), tuple-scope b:signed=a+5)	Functions, Variables	3g	omitting a defaulted input errors fcall-missing-arg today

Notes:

• requires/ensures were removed from the language. They parse today only to emit a "no obligation generated" warning; write an assume for a precondition and an assert for a postcondition.
• A design-body assert is checked by pass.formal and emitted into the Verilog netlist, but is not executed by lhd sim — the simulation runtime fallback is pending. Only assertions written inside a test block are checked at simulation time.
• A verification statement does not inherit an enclosing if guard: if c { assert(x) } is lowered as an unconditional assert(x). Use assert(c implies x).
• A refutable assume over free inputs is a hard build error at the top module and a deferred runtime check in an instantiated one.
• Runtime wrap/sat lowering and enum-typed register resets are implemented (earlier limitations, since fixed).
• Glob import patterns were removed from the language: the import string is "file" or "file.pub_name" only (see import).
• The comptime [...] test-parameter sweep (one test instance per swept value, the planned replacement for the for { test ... } fan-out idiom) is reserved but not yet specified.