From 72373438d28eecfa565ad16bd84f800b8c8067c0 Mon Sep 17 00:00:00 2001
From: Marijn Haverbeke <marijnh@gmail.com>
Date: Wed, 22 Feb 2012 13:06:38 +0100
Subject: [PATCH] Add core::to_str module

Provides a central iface for the various stringification
functions.
---
 src/libcore/core.rc   |  5 +++
 src/libcore/to_str.rs | 91 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100644 src/libcore/to_str.rs

diff --git a/src/libcore/core.rc b/src/libcore/core.rc
index 12a45498983..933513c2019 100644
--- a/src/libcore/core.rc
+++ b/src/libcore/core.rc
@@ -38,6 +38,7 @@ export comm, task, future;
 export extfmt;
 export math, bessel;
 export tuple;
+export to_str;
 
 // Built-in-type support modules
 
@@ -74,6 +75,10 @@ mod result;
 mod tuple;
 mod iter;
 
+// Useful ifaces
+
+mod to_str;
+
 // Runtime and language-primitive support
 
 mod ctypes;
diff --git a/src/libcore/to_str.rs b/src/libcore/to_str.rs
new file mode 100644
index 00000000000..e361fc5e514
--- /dev/null
+++ b/src/libcore/to_str.rs
@@ -0,0 +1,91 @@
+iface to_str { fn to_str() -> str; }
+
+impl of to_str for int {
+    fn to_str() -> str { int::str(self) }
+}
+impl of to_str for uint {
+    fn to_str() -> str { uint::str(self) }
+}
+impl of to_str for u8 {
+    fn to_str() -> str { uint::str(self as uint) }
+}
+impl of to_str for float {
+    fn to_str() -> str { float::to_str(self, 4u) }
+}
+impl of to_str for bool {
+    fn to_str() -> str { bool::to_str(self) }
+}
+impl of to_str for () {
+    fn to_str() -> str { "()" }
+}
+impl of to_str for str {
+    fn to_str() -> str { self }
+}
+
+impl <A: to_str copy, B: to_str copy> of to_str for (A, B) {
+    fn to_str() -> str {
+        let (a, b) = self;
+        "(" + a.to_str() + ", " + b.to_str() + ")"
+    }
+}
+impl <A: to_str copy, B: to_str copy, C: to_str copy> of to_str for (A, B, C){
+    fn to_str() -> str {
+        let (a, b, c) = self;
+        "(" + a.to_str() + ", " + b.to_str() + ", " + c.to_str() + ")"
+    }
+}
+
+impl <A: to_str> of to_str for [A] {
+    fn to_str() -> str {
+        let acc = "[", first = true;
+        for elt in self {
+            if first { first = false; }
+            else { acc += ", "; }
+            acc += elt.to_str();
+        }
+        acc += "]";
+        acc
+    }
+}
+
+impl <A: to_str> of to_str for @A {
+    fn to_str() -> str { "@" + (*self).to_str() }
+}
+impl <A: to_str> of to_str for ~A {
+    fn to_str() -> str { "~" + (*self).to_str() }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_simple_types() {
+        assert 1.to_str() == "1";
+        assert (-1).to_str() == "-1";
+        assert 200u.to_str() == "200";
+        assert 2u8.to_str() == "2";
+        assert true.to_str() == "true";
+        assert false.to_str() == "false";
+        assert ().to_str() == "()";
+        assert "hi".to_str() == "hi";
+    }
+
+    #[test]
+    fn test_tuple_types() {
+        assert (1, 2).to_str() == "(1, 2)";
+        assert ("a", "b", false).to_str() == "(a, b, false)";
+        assert ((), ((), 100)).to_str() == "((), ((), 100))";
+    }
+
+    fn test_vectors() {
+        let x: [int] = [];
+        assert x.to_str() == "[]";
+        assert [1].to_str() == "[1]";
+        assert [1, 2, 3].to_str() == "[1, 2, 3]";
+        assert [[], [1], [1, 1]].to_str() == "[[], [1], [1, 1]]";
+    }
+
+    fn test_pointer_types() {
+        assert (@1).to_str() == "@1";
+        assert (~(true, false)).to_str() == "~(true, false)";
+    }
+}