Struct SqpIterationInfo 

pub struct SqpIterationInfo<'a> {
    pub iter: u32,
    pub obj: Number,
    pub inf_pr: Number,
    pub inf_du: Number,
    pub p_inf: Number,
    pub alpha: Number,
    pub x: &'a [Number],
    pub lambda_g: &'a [Number],
    pub lambda_x: &'a [Number],
    pub c_vals: &'a [Number],
    pub grad_lag_x: &'a [Number],
}

What the per-iteration hook sees: the iterate x_k and the residuals measured at it (the same numbers the sqp_print_level >= 1 row prints), plus the step that arrived there.

Fields

iter: u32

obj: Number

inf_pr: Number

inf_du: Number

p_inf: Number

‖p‖_inf of the accepted step into this iterate (0 on iteration 0).

alpha: Number

Line-search step length of that step (0 on iteration 0).

x: &'a [Number]

lambda_g: &'a [Number]

[λ_c; λ_d] in algorithm space.

lambda_x: &'a [Number]

Signed bound multiplier z_L - z_U per variable.

c_vals: &'a [Number]

[c(x); d(x)] in algorithm space.

grad_lag_x: &'a [Number]

∇f + Jᵀλ_g − λ_x (the stationarity residual check_kkt measures) in algorithm space, from this iterate’s ∇f and J.