Enum Dsv4Encoding 

pub enum Dsv4Encoding {
    Preview,
    V0731,
}

Which encoding_dsv4.py revision governs the deepseek-v4 REASONING-EFFORT ladder (0731 re-gate, 2026-08-18 — research/dsv4-template-20260818/ENCODING-DIFF.md).

The two shipped encodings differ ONLY here; every other rendering law (roles, tool blocks, transitions, special tokens, think-mode prefixes, parsing) is byte-identical:

reasoning_effort	Preview (base repo @ 60d8d707)	V0731 (0731 @ 7872f01b)
None	no prefix	no prefix (None == “low” default)
“low”	INVALID upstream (assert) — renders as no prefix here	no prefix
“high”	documented NO-OP (== None)	DS_EFFORT_ABSOLUTE_MAX prefix
“max”	DS_EFFORT_ABSOLUTE_MAX prefix	DS_EFFORT_BEYOND_MAX prefix

The prefix (when non-empty) is injected once, before the first rendered message, in thinking mode only; chat mode never renders a prefix under either encoding.

DETECTION IS CONFIG-KEYED, never filename-keyed: the 0731 checkpoint added exactly four dspark_* keys to config.json in the same revision that remapped the ladder (dspark_block_size, dspark_markov_rank, dspark_noise_token_id, dspark_target_layer_ids); tokenizer/template files are byte-identical across the two checkpoints, so config.json is the artifact’s only encoding marker. Tokenizer::from_hf_dir performs the census (all four -> V0731, none -> Preview, a partial set refuses to load). Callers that cannot know the revision pass None; rendering then REFUSES exactly the (thinking, “high”/“max”) requests whose bytes differ between revisions and stays infallible everywhere the two encodings agree.

Variants

Preview

deepseek-ai/DeepSeek-V4-Flash (preview) law: {None,“high”} no-op, “max” -> absolute.

V0731

DeepSeek-V4-Flash-0731 law: None/“low” no prefix, “high” -> absolute, “max” -> beyond.

Trait Implementations

impl Clone for Dsv4Encoding

fn clone(&self) -> Dsv4Encoding

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Dsv4Encoding

impl Debug for Dsv4Encoding

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Dsv4Encoding

impl PartialEq for Dsv4Encoding

fn eq(&self, other: &Dsv4Encoding) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Dsv4Encoding