More utility functions

- join("a", "b", "c", sep: ", ")
- int("12")
- float("31.4e-1")
- str(10)
- sorted((3, 2, 1))

1 files changed, 23 insertions, 0 deletions

diff --git a/src/eval/str.rs b/src/eval/str.rs
index a358cd9f..099a4363 100644
--- a/src/eval/str.rs
+++ b/src/eval/str.rs
@@ -1,3 +1,4 @@
+use std::borrow::Borrow;
 use std::convert::TryFrom;
 use std::fmt::{self, Debug, Display, Formatter, Write};
 use std::ops::{Add, AddAssign, Deref};
@@ -5,6 +6,16 @@ use std::ops::{Add, AddAssign, Deref};
 use crate::diag::StrResult;
 use crate::util::EcoString;
 
+/// Create a new [`Str`] from a format string.
+macro_rules! format_str {
+    ($($tts:tt)*) => {{
+        use std::fmt::Write;
+        let mut s = $crate::util::EcoString::new();
+        write!(s, $($tts)*).unwrap();
+        $crate::eval::Str::from(s)
+    }};
+}
+
 /// A string value with inline storage and clone-on-write semantics.
 #[derive(Default, Clone, Eq, PartialEq, Ord, PartialOrd)]
 pub struct Str(EcoString);
@@ -92,6 +103,18 @@ impl AddAssign for Str {
     }
 }
 
+impl AsRef<str> for Str {
+    fn as_ref(&self) -> &str {
+        self
+    }
+}
+
+impl Borrow<str> for Str {
+    fn borrow(&self) -> &str {
+        self
+    }
+}
+
 impl From<char> for Str {
     fn from(c: char) -> Self {
         Self(c.into())