"""Minimal vendored replacements for the two espnet symbols multiconv_cgmlp
needs, so the model runs without installing espnet."""
import torch
import torch.nn as nn


class LayerNorm(nn.LayerNorm):
    """espnet LayerNorm: nn.LayerNorm over `nout`, optionally on a given dim."""
    def __init__(self, nout, dim=-1):
        super().__init__(nout, eps=1e-12)
        self.dim = dim

    def forward(self, x):
        if self.dim == -1:
            return super().forward(x)
        return super().forward(x.transpose(self.dim, -1)).transpose(self.dim, -1)


def get_activation(name):
    return {"silu": nn.SiLU(), "swish": nn.SiLU(), "relu": nn.ReLU(),
            "gelu": nn.GELU(), "identity": nn.Identity()}[name]