in midst of refactor

orchidlang/src/intermediate/ir_to_nort.rs

@@ -0,0 +1,37 @@
+//! Convert IR to the interpreter's NORT representation
+
+use super::ir;
+use crate::interpreter::nort;
+use crate::interpreter::nort_builder::NortBuilder;
+
+fn expr(expr: &ir::Expr, ctx: NortBuilder<(), usize>) -> nort::Expr {
+  clause(&expr.value, ctx).into_expr(expr.location.clone())
+}
+
+fn clause(cls: &ir::Clause, ctx: NortBuilder<(), usize>) -> nort::Clause {
+  match cls {
+    ir::Clause::Constant(name) => nort::Clause::Constant(name.clone()),
+    ir::Clause::Atom(a) => nort::Clause::Atom(a.run()),
+    ir::Clause::LambdaArg(n) => {
+      ctx.arg_logic(n);
+      nort::Clause::LambdaArg
+    },
+    ir::Clause::Apply(f, x) => ctx.apply_logic(|c| expr(f, c), |c| expr(x, c)),
+    ir::Clause::Lambda(body) => ctx.lambda_logic(&(), |c| expr(body, c)),
+  }
+}
+
+/// Convert an expression.
+pub fn ir_to_nort(expr: &ir::Expr) -> nort::Expr {
+  let c = NortBuilder::new(&|count| {
+    let mut count: usize = *count;
+    Box::new(move |()| match count {
+      0 => true,
+      _ => {
+        count -= 1;
+        false
+      },
+    })
+  });
+  nort::ClauseInst::new(clause(&expr.value, c)).into_expr(expr.location.clone())
+}