1 files changed, 52 insertions, 0 deletions
diff --git a/src/makefile/eval_context.rs b/src/makefile/eval_context.rs
new file mode 100644
index 0000000..06f4fbf
--- /dev/null
+++ b/src/makefile/eval_context.rs
@@ -0,0 +1,52 @@
+use eyre::{Result, WrapErr};
+use std::io::{BufRead, Cursor};
+use std::rc::Rc;
+
+use crate::makefile::input::FinishedMakefileReader;
+use crate::makefile::MakefileReader;
+
+pub struct DeferredEvalContext<'parent, 'args, 'grandparent, R: BufRead> {
+    parent: &'parent MakefileReader<'args, 'grandparent, R>,
+    children: Vec<FinishedMakefileReader>,
+}
+
+impl<'parent, 'args, 'grandparent, R: BufRead>
+    DeferredEvalContext<'parent, 'args, 'grandparent, R>
+{
+    pub fn new(parent: &'parent MakefileReader<'args, 'grandparent, R>) -> Self {
+        Self {
+            parent,
+            children: Vec::new(),
+        }
+    }
+
+    pub fn push(&mut self, child: FinishedMakefileReader) {
+        self.children.push(child);
+    }
+
+    pub fn eval(&mut self, to_eval: String) -> Result<()> {
+        let child_macros = self.parent.macros.with_overlay();
+        let child = MakefileReader::read(
+            self.parent.args,
+            child_macros,
+            Cursor::new(to_eval),
+            "<eval>",
+            Rc::clone(&self.parent.file_names),
+        )
+        .context("while evaling")?
+        .finish();
+        self.push(child);
+        Ok(())
+    }
+}
+
+impl<'parent, 'args, 'grandparent, R: BufRead> IntoIterator
+    for DeferredEvalContext<'parent, 'args, 'grandparent, R>
+{
+    type Item = FinishedMakefileReader;
+    type IntoIter = std::vec::IntoIter<Self::Item>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.children.into_iter()
+    }
+}