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54 lines
1.4 KiB
Rust
54 lines
1.4 KiB
Rust
// Copyright 2019 Jeremy Wall
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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use std::collections::BTreeMap;
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use std::rc::Rc;
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use crate::ast::Position;
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use super::Value;
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#[derive(Clone, PartialEq, Debug)]
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pub struct Stack {
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curr: BTreeMap<String, (Rc<Value>, Position)>,
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}
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impl Stack {
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pub fn new() -> Self {
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Stack {
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curr: BTreeMap::new(),
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}
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}
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pub fn get(&self, name: &str) -> Option<(Rc<Value>, Position)> {
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self.curr.get(name).cloned()
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}
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pub fn is_bound(&self, name: &str) -> bool {
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self.curr.get(name).is_some()
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}
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pub fn add(&mut self, name: String, val: Rc<Value>, pos: Position) {
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self.curr.insert(name, (val, pos));
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}
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pub fn symbol_list(&self) -> Vec<&String> {
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self.curr.keys().collect()
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}
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pub fn snapshot(&self) -> Self {
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Self {
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curr: self.curr.clone(),
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}
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}
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}
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