variable refactor: export builtin

1 files changed, 47 insertions, 5 deletions

diff --git a/src/run/var.rs b/src/run/var.rs
index 0e64ad7..d3e98f4 100644
--- a/src/run/var.rs
+++ b/src/run/var.rs
@@ -1,4 +1,7 @@
+use std::borrow::Cow;
 use std::collections::{HashMap, HashSet};
+use std::sync::LazyLock;
+use std::time::Instant;
 
 use crate::BString;
 use crate::bstr;
@@ -7,6 +10,7 @@ pub struct Vars {
     simple: HashMap<BString, BString>,
     magic: HashMap<BString, fn() -> BString>,
     all: HashSet<BString>,
+    export: HashSet<BString>,
 }
 
 impl Vars {
@@ -22,7 +26,15 @@ impl Vars {
             .cloned()
             .chain(magic.keys().cloned())
             .collect();
-        Self { simple, magic, all }
+        let export = std::env::vars_os()
+            .map(|x| x.0.into_encoded_bytes())
+            .collect();
+        Self {
+            simple,
+            magic,
+            all,
+            export,
+        }
     }
 
     pub fn set(&mut self, var: BString, val: BString) {
@@ -30,18 +42,36 @@ impl Vars {
         self.all.insert(var);
     }
 
-    pub fn lookup(&self, var: &bstr) -> Option<BString> {
+    pub fn lookup<'a>(&'a self, var: &bstr) -> Option<Cow<'a, bstr>> {
         if let Some(fun) = self.magic.get(var) {
-            return Some(fun());
+            return Some(Cow::Owned(fun()));
         }
 
         if let Some(val) = self.simple.get(var) {
-            return Some(val.clone());
+            return Some(Cow::Borrowed(val));
         }
 
         None
     }
 
+    pub fn allow_export(&mut self, var: &bstr, allow: bool) {
+        if allow {
+            self.export.insert(var.to_vec());
+        } else {
+            self.export.remove(var);
+        }
+    }
+
+    pub fn export<'a>(&'a self) -> HashMap<&'a bstr, Cow<'a, bstr>> {
+        self.export
+            .iter()
+            .filter_map(|var| {
+                let val = self.lookup(var)?;
+                Some((var.as_ref(), val))
+            })
+            .collect()
+    }
+
     pub fn vars(&self) -> &HashSet<BString> {
         &self.all
     }
@@ -62,9 +92,21 @@ impl Default for Vars {
             b"PISH_COMMIT" => crate::consts::PISH_COMMIT.as_bytes().to_vec(),
             b"PISH_DIRTY" => vec![crate::consts::PISH_DIRTY as u8 + b'0'],
         };
+
         let magic = map! {
-            b"CWD_PRETTY" => crate::pretty_cwd as _
+            b"CWD_PRETTY" => crate::pretty_cwd as _,
+            b"SECONDS" => seconds_since_startup as _,
         };
+
+        // call it once such that lazylock gets initialized
+        seconds_since_startup();
+
         Self::new(simple, magic)
     }
 }
+
+static START: LazyLock<Instant> = LazyLock::new(Instant::now);
+
+fn seconds_since_startup() -> BString {
+    format!("{}", START.elapsed().as_secs_f64() as u64).into_bytes()
+}