1 files changed, 53 insertions, 0 deletions
diff --git a/src/makefile/eval_context.rs b/src/makefile/eval_context.rs
new file mode 100644
index 0000000..87edafd
--- /dev/null
+++ b/src/makefile/eval_context.rs
@@ -0,0 +1,53 @@
+use eyre::{Result, WrapErr};
+use std::io::{BufRead, Cursor};
+use std::rc::Rc;
+
+use super::{FinishedMakefileReader, MacroSet, 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 const 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_stack = self.parent.stack.with_scope(&self.parent.macros);
+        let child_macros = MacroSet::new();
+        let child = MakefileReader::read(
+            self.parent.args,
+            child_stack,
+            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()
+    }
+}