From 2aa89daab3a8351a03f6d57d3e1f737cccd59850 Mon Sep 17 00:00:00 2001 From: Linus Heckemann Date: Thu, 21 Mar 2019 14:32:20 +0100 Subject: [PATCH] eval: improve type description for primops and applied primops This can make type errors a little easier to understand. --- src/libexpr/eval.cc | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 2a194d0e0..211f7a55f 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -130,6 +130,16 @@ std::ostream & operator << (std::ostream & str, const Value & v) } +const Value *getPrimOp(const Value &v) { + const Value * primOp = &v; + while (primOp->type == tPrimOpApp) { + primOp = primOp->primOpApp.left; + } + assert(primOp->type == tPrimOp); + return primOp; +} + + string showType(const Value & v) { switch (v.type) { @@ -144,8 +154,10 @@ string showType(const Value & v) case tApp: return "a function application"; case tLambda: return "a function"; case tBlackhole: return "a black hole"; - case tPrimOp: return "a built-in function"; - case tPrimOpApp: return "a partially applied built-in function"; + case tPrimOp: + return fmt("the built-in function '%s'", string(v.primOp->name)); + case tPrimOpApp: + return fmt("the partially applied built-in function '%s'", string(getPrimOp(v)->primOp->name)); case tExternal: return v.external->showType(); case tFloat: return "a float"; }