Add the 'alias' built-in command

The shell now has support for aliases (via alias foo=bar). The 'unalias'
command is also available to remove aliases. Finally,
Environment::aliases was changed to be a HashMap<String, String>,
instead of a Vec<String>.

Since the verse's verb might change (for instance, it is an environment
variable, or an alias), add another check in Poem::recite, which simply
continues, instead of running the spellchecker, if the verb is empty.

1 files changed, 5 insertions, 3 deletions

diff --git a/src/compose/environment.rs b/src/compose/environment.rs
index 219a597..df83e4f 100644
--- a/src/compose/environment.rs
+++ b/src/compose/environment.rs
@@ -1,13 +1,15 @@
+use std::collections::HashMap;
+
 pub struct Environment {
-    pub aliases: Vec<String>,
+    pub aliases: HashMap<String, String>,
     pub bins: Vec<String>,
 }
 
 impl Environment {
     pub fn new() -> Self {
         Environment {
-            aliases: vec![],
-            bins: vec![],
+            aliases: HashMap::new(),
+            bins: Vec::new(),
         }
     }
 }