diff options
author | Nadrieril | 2019-03-06 16:30:40 +0100 |
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committer | Nadrieril | 2019-03-06 16:30:40 +0100 |
commit | 4d92f06c98c98c014a02c218b6c31cf81d9f0fec (patch) | |
tree | 30a2e3e0879c58c866a3ae0ed7cbebf2c4a1cfa6 /dhall | |
parent | 45992d093b950170fc30e63d2c7d7a2767e9b9e8 (diff) |
Move context to dhall_core
Diffstat (limited to 'dhall')
-rw-r--r-- | dhall/src/context.rs | 56 | ||||
-rw-r--r-- | dhall/src/lib.rs | 1 | ||||
-rw-r--r-- | dhall/src/typecheck.rs | 2 |
3 files changed, 1 insertions, 58 deletions
diff --git a/dhall/src/context.rs b/dhall/src/context.rs deleted file mode 100644 index b88a677..0000000 --- a/dhall/src/context.rs +++ /dev/null @@ -1,56 +0,0 @@ -use std::collections::HashMap; - -/// A `(Context a)` associates `Text` labels with values of type `a` -/// -/// The `Context` is used for type-checking when `(a = Expr X)` -/// -/// * You create a `Context` using `empty` and `insert` -/// * You transform a `Context` using `fmap` -/// * You consume a `Context` using `lookup` and `toList` -/// -/// The difference between a `Context` and a `Map` is that a `Context` lets you -/// have multiple ordered occurrences of the same key and you can query for the -/// `n`th occurrence of a given key. -/// -#[derive(Debug, Clone)] -pub struct Context<'i, T>(HashMap<&'i str, Vec<T>>); - -impl<'i, T> Context<'i, T> { - /// An empty context with no key-value pairs - pub fn new() -> Self { - Context(HashMap::new()) - } - - /// Look up a key by name and index - /// - /// ```c - /// lookup _ _ empty = Nothing - /// lookup k 0 (insert k v c) = Just v - /// lookup k n (insert k v c) = lookup k (n - 1) c -- 1 <= n - /// lookup k n (insert j v c) = lookup k n c -- k /= j - /// ``` - pub fn lookup<'a>(&'a self, k: &str, n: usize) -> Option<&'a T> { - self.0.get(k).and_then(|v| v.get(v.len() - 1 - n)) - } - - pub fn map<U, F: Fn(&T) -> U>(&self, f: F) -> Context<'i, U> { - Context( - self.0 - .iter() - .map(|(k, v)| (*k, v.iter().map(&f).collect())) - .collect(), - ) - } -} - -impl<'i, T: Clone> Context<'i, T> { - /// Add a key-value pair to the `Context` - pub fn insert(&self, k: &'i str, v: T) -> Self { - let mut ctx = (*self).clone(); - { - let m = ctx.0.entry(k).or_insert_with(Vec::new); - m.push(v); - } - ctx - } -} diff --git a/dhall/src/lib.rs b/dhall/src/lib.rs index 902df53..32662cd 100644 --- a/dhall/src/lib.rs +++ b/dhall/src/lib.rs @@ -1,5 +1,4 @@ #![feature(box_patterns)] #![feature(trace_macros)] -pub mod context; pub mod typecheck; diff --git a/dhall/src/typecheck.rs b/dhall/src/typecheck.rs index 26192d2..aa8aa08 100644 --- a/dhall/src/typecheck.rs +++ b/dhall/src/typecheck.rs @@ -3,7 +3,7 @@ use std::collections::BTreeMap; use std::collections::HashSet; use std::fmt; -use crate::context::Context; +use dhall_core::context::Context; use dhall_core::core; use dhall_core::core::Builtin::*; use dhall_core::core::Const::*; |