Construct ArrayStorage directly in matrix![]

This commit is contained in:
Andreas Longva 2021-04-17 09:43:55 +02:00
parent e60136fbb1
commit ec2a5a3909
2 changed files with 21 additions and 11 deletions

View File

@ -4,9 +4,12 @@ use syn::{Expr};
use syn::parse::{Parse, ParseStream, Result, Error};
use syn::punctuated::{Punctuated};
use syn::{parse_macro_input, Token};
use quote::{quote, format_ident};
use quote::{quote, TokenStreamExt};
use proc_macro::TokenStream;
use proc_macro2::{TokenStream as TokenStream2, Delimiter, TokenTree, Spacing};
use proc_macro2::{Group, Punct};
struct Matrix {
// Represent the matrix as a row-major vector of vectors of expressions
rows: Vec<Vec<Expr>>,
@ -22,14 +25,18 @@ impl Matrix {
self.ncols
}
fn to_col_major_repr(&self) -> Vec<Expr> {
let mut data = Vec::with_capacity(self.nrows() * self.ncols());
/// Produces a stream of tokens representing this matrix as a column-major array.
fn col_major_array_tokens(&self) -> TokenStream2 {
let mut result = TokenStream2::new();
for j in 0 .. self.ncols() {
for i in 0 .. self.nrows() {
data.push(self.rows[i][j].clone());
let mut col = TokenStream2::new();
let col_iter = (0 .. self.nrows())
.map(move |i| &self.rows[i][j]);
col.append_separated(col_iter, Punct::new(',', Spacing::Alone));
result.append(Group::new(Delimiter::Bracket, col));
result.append(Punct::new(',', Spacing::Alone));
}
}
data
TokenStream2::from(TokenTree::Group(Group::new(Delimiter::Bracket, result)))
}
}
@ -79,13 +86,16 @@ pub fn matrix(stream: TokenStream) -> TokenStream {
let row_dim = matrix.nrows();
let col_dim = matrix.ncols();
let entries_col_major = matrix.to_col_major_repr();
let array_tokens = matrix.col_major_array_tokens();
// TODO: Use quote_spanned instead??
// TODO: Construct directly from array?
// TODO: Avoid use of unsafe here
let output = quote! {
unsafe {
nalgebra::SMatrix::<_, #row_dim, #col_dim>
::from_column_slice(&[#(#entries_col_major),*])
::from_data_statically_unchecked(nalgebra::ArrayStorage(#array_tokens))
}
};
proc_macro::TokenStream::from(output)

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@ -1,5 +1,5 @@
use nalgebra_macros::matrix;
use nalgebra::{SMatrix, Matrix3x2, U0, U1, Matrix1x2, Matrix1x3, Matrix1x4, Matrix2x1, Matrix2, Matrix2x3, Matrix2x4, Matrix3x1, Matrix3, Matrix3x4, Matrix4x1, Matrix4x2, Matrix4x3, Matrix4};
use nalgebra::{SMatrix, Matrix3x2, Matrix1x2, Matrix1x3, Matrix1x4, Matrix2x1, Matrix2, Matrix2x3, Matrix2x4, Matrix3x1, Matrix3, Matrix3x4, Matrix4x1, Matrix4x2, Matrix4x3, Matrix4};
#[test]
fn matrix_small_dims_exhaustive() {