Struct GepConfig 

pub struct GepConfig {
    pub head_len: usize,
    pub tail_len: usize,
    pub pop_size: usize,
    pub n_vars: usize,
    pub mutation_rate: Probability,
    pub is_transpose_rate: Probability,
    pub ris_transpose_rate: Probability,
    pub crossover_1p_rate: Probability,
    pub crossover_2p_rate: Probability,
}

Static parameters for a GepStrategy run.

GEP chromosomes are fixed-length: a head of head_len loci (which may hold any symbol) followed by a tail of tail_len loci (terminals only). The tail length is not a free parameter — it is derived from the head length and the function set’s maximum arity so that every chromosome decodes to a complete expression tree without repair (see GepConfig::new).

Unlike the const-generic experiments considered during design, the genome dimensions are ordinary runtime fields (matching the shipped CgpConfig precedent); no generic_const_exprs is required.

Fields

head_len: usize

Head length: number of leading loci that may hold any symbol.

tail_len: usize

Tail length: number of trailing loci that may hold terminals only.

Derived in GepConfig::new as head_len * (max_arity - 1) + 1.

pop_size: usize

Number of individuals in the population.

n_vars: usize

Number of input variables the program sees.

mutation_rate: Probability

Per-gene point-mutation probability. Valid by construction ([0, 1]).

is_transpose_rate: Probability

Per-individual probability of applying one IS transposition. Valid by construction ([0, 1]).

ris_transpose_rate: Probability

Per-individual probability of applying one RIS transposition. Valid by construction ([0, 1]).

crossover_1p_rate: Probability

Per-pair probability of one-point crossover. Valid by construction ([0, 1]).

crossover_2p_rate: Probability

Per-pair probability of two-point crossover. Valid by construction ([0, 1]).

Implementations

impl GepConfig

pub fn new( head_len: usize, max_arity: usize, n_vars: usize, pop_size: usize, ) -> Result<Self, ConfigError>

Builds a config, deriving and validating the tail length.

The tail length is set to head_len * (max_arity - 1) + 1, the minimum that guarantees any head/tail-respecting chromosome decodes to a complete tree. max_arity is the function set’s largest arity (FunctionSet::max_arity).

Operator rates default to canonical Ferreira (2001) values; assign a validated Probability to the public fields afterwards to override. The point-mutation rate defaults to 2 / genome_len (≈ two genes per chromosome). Because the rates are Probability, a NaN/Inf/ out-of-[0, 1] rate is unrepresentable — the silent operator degeneracy of a bare f32 rate cannot occur.

Errors

Returns a ConfigError if max_arity, head_len, n_vars, or pop_size is zero — each would make the genome layout or the tree decode degenerate. max_arity is checked here (it is consumed to derive tail_len rather than stored); the remaining field invariants are checked via Validate.

pub fn genome_len(&self) -> usize

Total chromosome length (head_len + tail_len).

Trait Implementations

impl Clone for GepConfig

fn clone(&self) -> GepConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for GepConfig

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

Formats the value using the given formatter.

impl Validate for GepConfig

fn validate(&self) -> Result<(), ConfigError>

Returns Ok(()) when every invariant holds, or the first ConfigError otherwise.

fn validate_all(&self) -> Result<(), Vec<ConfigError>>

Returns every violated invariant rather than just the first.