`dims(x)` on `array[ , ] vector[ ] x` outputs a size 4 array instead of size 3

[spinkney]

// test_dims.stan
data {
}
parameters {
    array[1, 1] vector[1] x;
}
transformed parameters {
    print("dims(x): ", dims(x));
}
model {
    x[1, 1, 1] ~ std_normal();
}

Using cmdstan 2.38

library(cmdstanr)

mod_test <- cmdstan_model("test_dims.stan")
mod_test$sample()

Output

Chain 3 dims(x): [1,1,1,1] 
Chain 3 dims(x): [1,1,1,1] 
Chain 3 dims(x): [1,1,1,1]