Rewriting codegen'

codegen/src/lib.rs

@@ -0,0 +1,63 @@
+pub mod expr;
+pub mod statement;
+pub mod top_level;
+
+use mist_parser::ast::*;
+
+pub trait GenRust {
+    fn get_rust(&self, cg: &mut RustCodegen);
+}
+
+#[derive(Default)]
+pub struct RustCodegen {
+    output: String,
+    indent: usize,
+}
+
+impl RustCodegen {
+    pub fn new() -> Self {
+        Self {
+            output: String::new(),
+            indent: 0,
+        }
+    }
+
+    fn indent_str(&self) -> String {
+        "    ".repeat(self.indent)
+    }
+
+    fn add(&mut self, s: &str) {
+        self.output.push_str(s);
+    }
+
+    fn addln(&mut self, s: &str) {
+        self.add(s);
+        self.add("\n");
+    }
+
+    fn add_indentedln(&mut self, s: &str) {
+        let line = format!("{}{}\n", self.indent_str(), s);
+        self.add(&line);
+    }
+
+    pub fn generate(&mut self, toplevels: Vec<TopLevel>) -> String {
+        for tl in toplevels {
+            tl.to_rust(self);
+        }
+
+        self.output.clone()
+    }
+
+    pub fn ensure_brackets(&mut self, stmt: Box<Statement>) {
+        match *stmt {
+            Statement::Block(_) => stmt.to_rust(self),
+            _ => {
+                self.add_indentedln("{");
+                self.indent += 1;
+                stmt.to_rust(self);
+                self.indent -= 1;
+                self.add_indentedln("}");
+            }
+        }
+    }
+}