move json into a directory, add builder helper

src/json/builder.rs

@@ -0,0 +1,127 @@
+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::collections::TreeMap;
+use std::str::StrAllocating;
+
+use super::{Json, List, Object, ToJson};
+
+pub struct ListBuilder {
+    list: Vec<Json>,
+}
+
+impl ListBuilder {
+    pub fn new() -> ListBuilder {
+        ListBuilder { list: Vec::new() }
+    }
+
+    pub fn unwrap(self) -> Json {
+        List(self.list)
+    }
+
+    pub fn push<T: ToJson>(self, value: T) -> ListBuilder {
+        let mut builder = self;
+        builder.list.push(value.to_json());
+        builder
+    }
+
+    pub fn push_list(self, f: |ListBuilder| -> ListBuilder) -> ListBuilder {
+        let builder = ListBuilder::new();
+        self.push(f(builder).unwrap())
+    }
+
+    pub fn push_object(self, f: |ObjectBuilder| -> ObjectBuilder) -> ListBuilder {
+        let builder = ObjectBuilder::new();
+        self.push(f(builder).unwrap())
+    }
+}
+
+pub struct ObjectBuilder {
+    object: Object,
+}
+
+impl ObjectBuilder {
+    pub fn new() -> ObjectBuilder {
+        ObjectBuilder { object: TreeMap::new() }
+    }
+
+    pub fn unwrap(self) -> Json {
+        Object(self.object)
+    }
+
+    pub fn insert<T: ToJson>(self, key: String, value: T) -> ObjectBuilder {
+        let mut builder = self;
+        builder.object.insert(key, value.to_json());
+        builder
+    }
+
+    pub fn insert_list<S: StrAllocating>(self, key: S, f: |ListBuilder| -> ListBuilder) -> ObjectBuilder {
+        let builder = ListBuilder::new();
+        self.insert(key.into_string(), f(builder).unwrap())
+    }
+
+    pub fn insert_object<S: StrAllocating>(self, key: S, f: |ObjectBuilder| -> ObjectBuilder) -> ObjectBuilder {
+        let builder = ObjectBuilder::new();
+        self.insert(key.into_string(), f(builder).unwrap())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use collections::TreeMap;
+    use super::super::{List, I64, Object};
+    use super::{ListBuilder, ObjectBuilder};
+
+    #[test]
+    fn test_list_builder() {
+        let value = ListBuilder::new().unwrap();
+        assert_eq!(value, List(Vec::new()));
+
+        let value = ListBuilder::new()
+            .push(1)
+            .push(2)
+            .push(3)
+            .unwrap();
+        assert_eq!(value, List(vec!(I64(1), I64(2), I64(3))));
+
+        let value = ListBuilder::new()
+            .push_list(|bld| bld.push(1).push(2).push(3))
+            .unwrap();
+        assert_eq!(value, List(vec!(List(vec!(I64(1), I64(2), I64(3))))));
+
+        let value = ListBuilder::new()
+            .push_object(|bld|
+                bld
+                    .insert("a".to_strbuf(), 1)
+                    .insert("b".to_strbuf(), 2))
+            .unwrap();
+
+        let mut map = TreeMap::new();
+        map.insert("a".to_strbuf(), I64(1));
+        map.insert("b".to_strbuf(), I64(2));
+        assert_eq!(value, List(vec!(Object(map))));
+    }
+
+    #[test]
+    fn test_object_builder() {
+        let value = ObjectBuilder::new().unwrap();
+        assert_eq!(value, Object(TreeMap::new()));
+
+        let value = ObjectBuilder::new()
+            .insert("a".to_strbuf(), 1)
+            .insert("b".to_strbuf(), 2)
+            .unwrap();
+
+        let mut map = TreeMap::new();
+        map.insert("a".to_strbuf(), I64(1));
+        map.insert("b".to_strbuf(), I64(2));
+        assert_eq!(value, Object(map));
+    }
+}

src/json/mod.rs

@@ -246,6 +246,8 @@ use de;
 use ser::Serializable;
 use ser;
 
+pub mod builder;
+
 /// Represents a json value
 #[deriving(Clone, PartialEq, PartialOrd)]
 pub enum Json {