58 lines
1.7 KiB
Rust
58 lines
1.7 KiB
Rust
/** Serene --- Yet an other Lisp
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*
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* Copyright (c) 2020 Sameer Rahmani <lxsameer@gnu.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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use crate::ast::Expr;
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use crate::compiler::Compiler;
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use crate::types::core::{ExprResult, Expression};
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#[derive(Debug, Eq, PartialEq, Clone)]
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pub struct List {
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first: Expr,
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rest: Expr,
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length: u64,
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}
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impl List {
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pub fn new(first: Expr, rest: Expr) -> List {
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// The order of field definition is important here.
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// If we move the `length` after `rest` we're going
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// to break the ownership rule of rust because `rest: rest`
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// is going to move it to the new list and we can not
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// borrow it afterward.
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List {
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length: match &rest {
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Expr::Cons(v) => v.length + 1,
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_ => {
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if let Expr::Nil = first {
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0
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} else {
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1
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}
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}
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},
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first,
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rest,
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}
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}
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}
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impl Expression for List {
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fn eval() {}
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fn code_gen<'ctx>(&self, compiler: &'ctx Compiler) -> ExprResult<'ctx> {
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Err("Not implemented on list".to_string())
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}
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}
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