gemini: add document builder

src/gemini.rs

@@ -2,6 +2,58 @@
 /// here: https://gemini.circumlunar.space/docs/specification.html
 use std::io::Write;
 
+/// Build a gemini document up from a series of nodes.
+#[derive(Default)]
+pub struct Builder {
+    nodes: Vec<Node>,
+}
+
+impl Builder {
+    pub fn new() -> Builder {
+        Builder::default()
+    }
+
+    pub fn text<T: Into<String>>(mut self, data: T) -> Builder {
+        self.nodes.push(Node::Text(data.into()));
+        self
+    }
+
+    pub fn link<T: Into<String>>(mut self, to: T, name: Option<String>) -> Builder {
+        self.nodes.push(Node::Link {
+            to: to.into(),
+            name: name,
+        });
+        self
+    }
+
+    pub fn preformatted<T: Into<String>>(mut self, data: T) -> Builder {
+        self.nodes.push(Node::Preformatted(data.into()));
+        self
+    }
+
+    pub fn heading<T: Into<String>>(mut self, level: u8, body: T) -> Builder {
+        self.nodes.push(Node::Heading {
+            level: level,
+            body: body.into(),
+        });
+        self
+    }
+
+    pub fn list_item<T: Into<String>>(mut self, item: T) -> Builder {
+        self.nodes.push(Node::ListItem(item.into()));
+        self
+    }
+
+    pub fn quote<T: Into<String>>(mut self, body: T) -> Builder {
+        self.nodes.push(Node::Quote(body.into()));
+        self
+    }
+
+    pub fn build(self) -> Vec<Node> {
+        self.nodes
+    }
+}
+
 /// Individual nodes of the document. Each node correlates to a line in the file.
 #[derive(Debug, PartialEq, Eq)]
 pub enum Node {