From 421a33c42c74f72b7d7834b090972d066de24f7d Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Thu, 14 Oct 2021 02:47:19 -0700
Subject: [PATCH] Use TryFrom<&str> for Tokens

---
 Cargo.lock                             |  2 --
 schala-lang/language/Cargo.toml        |  2 --
 schala-lang/language/src/lib.rs        |  4 ----
 schala-lang/language/src/tokenizing.rs | 23 ++++++++++++-----------
 4 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 1071a61..8ae5c95 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -836,8 +836,6 @@ dependencies = [
  "ena",
  "failure",
  "itertools",
- "lazy_static 1.4.0",
- "maplit",
  "radix_trie",
  "schala-lang-codegen",
  "schala-repl",
diff --git a/schala-lang/language/Cargo.toml b/schala-lang/language/Cargo.toml
index 39660be..a7fcefa 100644
--- a/schala-lang/language/Cargo.toml
+++ b/schala-lang/language/Cargo.toml
@@ -8,8 +8,6 @@ resolver = "2"
 [dependencies]
 itertools = "0.10"
 take_mut = "0.2.2"
-maplit = "1.0.1"
-lazy_static = "1.3.0"
 failure = "0.1.5"
 ena = "0.11.0"
 stopwatch = "0.0.7"
diff --git a/schala-lang/language/src/lib.rs b/schala-lang/language/src/lib.rs
index 39736f2..6c7f100 100644
--- a/schala-lang/language/src/lib.rs
+++ b/schala-lang/language/src/lib.rs
@@ -6,10 +6,6 @@
 //! It defines the `Schala` type, which contains the state for a Schala REPL, and implements
 //! `ProgrammingLanguageInterface` and the chain of compiler passes for it.
 
-#[macro_use]
-extern crate lazy_static;
-#[macro_use]
-extern crate maplit;
 extern crate schala_repl;
 #[macro_use]
 extern crate schala_lang_codegen;
diff --git a/schala-lang/language/src/tokenizing.rs b/schala-lang/language/src/tokenizing.rs
index 28f4a8e..b83a5d8 100644
--- a/schala-lang/language/src/tokenizing.rs
+++ b/schala-lang/language/src/tokenizing.rs
@@ -1,8 +1,5 @@
 use itertools::Itertools;
-use std::collections::HashMap;
-use std::rc::Rc;
-use std::iter::{Iterator, Peekable};
-use std::fmt;
+use std::{iter::{Iterator, Peekable}, convert::TryFrom, rc::Rc, fmt};
 
 use crate::source_map::Location;
 
@@ -63,9 +60,11 @@ pub enum Kw {
   Module, Import
 }
 
-lazy_static! {
-  static ref KEYWORDS: HashMap<&'static str, Kw> =
-    hashmap! {
+impl TryFrom<&str> for Kw {
+  type Error = ();
+
+  fn try_from(value: &str) -> Result<Self, Self::Error> {
+    Ok(match value {
       "if" => Kw::If,
       "then" => Kw::Then,
       "else" => Kw::Else,
@@ -88,7 +87,9 @@ lazy_static! {
       "false" => Kw::False,
       "module" => Kw::Module,
       "import" => Kw::Import,
-    };
+      _ => return Err(()),
+    })
+  }
 }
 
 #[derive(Debug, Clone, PartialEq)]
@@ -239,9 +240,9 @@ fn handle_alphabetic(c: char, input: &mut Peekable<impl Iterator<Item=CharData>>
     }
   }
 
-  match KEYWORDS.get(buf.as_str()) {
-    Some(kw) => TokenKind::Keyword(*kw),
-    None => TokenKind::Identifier(Rc::new(buf)),
+  match Kw::try_from(buf.as_str()) {
+    Ok(kw) => TokenKind::Keyword(kw),
+    Err(()) => TokenKind::Identifier(Rc::new(buf)),
   }
 }