From 489174a426e6057a68b6edd2e9b4387d09912a25 Mon Sep 17 00:00:00 2001
From: Nadrieril
Date: Wed, 29 Jan 2020 21:56:52 +0000
Subject: Move envs to their own files

---
 dhall/src/semantics/nze/nzexpr.rs | 116 --------------------------------------
 1 file changed, 116 deletions(-)
 delete mode 100644 dhall/src/semantics/nze/nzexpr.rs

(limited to 'dhall/src/semantics/nze/nzexpr.rs')

diff --git a/dhall/src/semantics/nze/nzexpr.rs b/dhall/src/semantics/nze/nzexpr.rs
deleted file mode 100644
index c065a5b..0000000
--- a/dhall/src/semantics/nze/nzexpr.rs
+++ /dev/null
@@ -1,116 +0,0 @@
-use crate::semantics::core::var::AlphaVar;
-use crate::syntax::{Label, V};
-
-pub(crate) type Binder = Label;
-
-#[derive(Debug, Clone)]
-pub(crate) struct NameEnv {
-    names: Vec<Binder>,
-}
-
-#[derive(Debug, Clone, Copy)]
-pub(crate) struct VarEnv {
-    size: usize,
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub(crate) enum NzVar {
-    /// Reverse-debruijn index: counts number of binders from the bottom of the stack.
-    Bound(usize),
-    /// Fake fresh variable generated for expression equality checking.
-    Fresh(usize),
-}
-
-impl NameEnv {
-    pub fn new() -> Self {
-        NameEnv { names: Vec::new() }
-    }
-    pub fn from_binders(names: impl Iterator<Item = Binder>) -> Self {
-        NameEnv {
-            names: names.collect(),
-        }
-    }
-    pub fn as_varenv(&self) -> VarEnv {
-        VarEnv {
-            size: self.names.len(),
-        }
-    }
-
-    pub fn insert(&self, x: &Binder) -> Self {
-        let mut env = self.clone();
-        env.insert_mut(x);
-        env
-    }
-    pub fn insert_mut(&mut self, x: &Binder) {
-        self.names.push(x.clone())
-    }
-    pub fn remove_mut(&mut self) {
-        self.names.pop();
-    }
-
-    pub fn unlabel_var(&self, var: &V<Binder>) -> Option<AlphaVar> {
-        let V(name, idx) = var;
-        let (idx, _) = self
-            .names
-            .iter()
-            .rev()
-            .enumerate()
-            .filter(|(_, n)| *n == name)
-            .nth(*idx)?;
-        Some(AlphaVar::new(V((), idx)))
-    }
-    pub fn label_var(&self, var: &AlphaVar) -> V<Binder> {
-        let name = &self.names[self.names.len() - 1 - var.idx()];
-        let idx = self
-            .names
-            .iter()
-            .rev()
-            .take(var.idx())
-            .filter(|n| *n == name)
-            .count();
-        V(name.clone(), idx)
-    }
-}
-
-impl VarEnv {
-    pub fn new() -> Self {
-        VarEnv { size: 0 }
-    }
-    pub fn size(&self) -> usize {
-        self.size
-    }
-    pub fn insert(&self) -> Self {
-        VarEnv {
-            size: self.size + 1,
-        }
-    }
-    pub fn lookup(&self, var: &NzVar) -> AlphaVar {
-        self.lookup_fallible(var).unwrap()
-    }
-    pub fn lookup_fallible(&self, var: &NzVar) -> Option<AlphaVar> {
-        let idx = self.size.checked_sub(var.idx() + 1)?;
-        Some(AlphaVar::new(V((), idx)))
-    }
-}
-
-impl NzVar {
-    pub fn new(idx: usize) -> Self {
-        NzVar::Bound(idx)
-    }
-    pub fn fresh() -> Self {
-        use std::sync::atomic::{AtomicUsize, Ordering};
-        // Global counter to ensure uniqueness of the generated id.
-        static FRESH_VAR_COUNTER: AtomicUsize = AtomicUsize::new(0);
-        let id = FRESH_VAR_COUNTER.fetch_add(1, Ordering::SeqCst);
-        NzVar::Fresh(id)
-    }
-    // Panics on a fresh variable.
-    pub fn idx(&self) -> usize {
-        match self {
-            NzVar::Bound(i) => *i,
-            NzVar::Fresh(_) => panic!(
-                "Trying to use a fresh variable outside of equality checking"
-            ),
-        }
-    }
-}
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