From 026ed48069857b258cd2558d91a9fef864b418b7 Mon Sep 17 00:00:00 2001
From: John Kerl <kerl.john.r@gmail.com>
Date: Mon, 23 Nov 2020 17:03:35 -0500
Subject: [PATCH] fix scoping for typedecl localvars in go impl

---
 go/cases-to-do.txt               |  4 +---
 go/src/miller/dsl/cst/lvalues.go | 37 ++++++++++++++++++++------------
 2 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/go/cases-to-do.txt b/go/cases-to-do.txt
index 389325065..042348de3 100644
--- a/go/cases-to-do.txt
+++ b/go/cases-to-do.txt
@@ -1,9 +1,6 @@
 ================================================================
 BUG:
 
-rrv ./reg-test/cases/case-c-dsl-localvar-scope-and-extent.sh
-* !!
-
 rrv ./reg-test/cases/case-c-dsl-empty-statements.sh
 * mlr_expect_fail -n filter -v ''
   C: "filter statement must not be empty"
@@ -239,3 +236,4 @@ rrv ./reg-test/cases/case-c-uniq.sh
 rrv ./reg-test/cases/case-c-utf8-bom.sh
 
 ================================================================
+rrv ./reg-test/cases/case-c-dsl-localvar-scope-and-extent.sh
diff --git a/go/src/miller/dsl/cst/lvalues.go b/go/src/miller/dsl/cst/lvalues.go
index a520de886..bfc3b3801 100644
--- a/go/src/miller/dsl/cst/lvalues.go
+++ b/go/src/miller/dsl/cst/lvalues.go
@@ -461,6 +461,14 @@ func (this *FullOosvarLvalueNode) UnsetIndexed(
 // ----------------------------------------------------------------
 type LocalVariableLvalueNode struct {
 	typeGatedMlrvalName *types.TypeGatedMlrvalName
+
+	// a = 1;
+	// b = 1;
+	// if (true) {
+	//   a = 3;     <-- frameBind is false; updates outer a
+	//   var b = 4; <-- frameBind is true;  creates new inner b
+	// }
+	frameBind bool
 }
 
 func (this *RootNode) BuildLocalVariableLvalueNode(astNode *dsl.ASTNode) (IAssignable, error) {
@@ -468,10 +476,12 @@ func (this *RootNode) BuildLocalVariableLvalueNode(astNode *dsl.ASTNode) (IAssig
 
 	variableName := string(astNode.Token.Lit)
 	typeName := "var"
+	frameBind := false
 	if astNode.Children != nil { // typed, like 'num x = 3'
 		typeNode := astNode.Children[0]
 		lib.InternalCodingErrorIf(typeNode.Type != dsl.NodeTypeTypedecl)
 		typeName = string(typeNode.Token.Lit)
+		frameBind = true
 	}
 	typeGatedMlrvalName, err := types.NewTypeGatedMlrvalName(
 		variableName,
@@ -483,14 +493,17 @@ func (this *RootNode) BuildLocalVariableLvalueNode(astNode *dsl.ASTNode) (IAssig
 	// TODO: type-gated mlrval
 	return NewLocalVariableLvalueNode(
 		typeGatedMlrvalName,
+		frameBind,
 	), nil
 }
 
 func NewLocalVariableLvalueNode(
 	typeGatedMlrvalName *types.TypeGatedMlrvalName,
+	frameBind bool,
 ) *LocalVariableLvalueNode {
 	return &LocalVariableLvalueNode{
 		typeGatedMlrvalName: typeGatedMlrvalName,
+		frameBind:           frameBind,
 	}
 }
 
@@ -514,23 +527,19 @@ func (this *LocalVariableLvalueNode) AssignIndexed(
 			return err
 		}
 
-		// TODO: Needs BindVariable if done with a type
-		//
-		//   a = 1;
-		//   if (true) {
-		//     a = 2; <-- do reuse: SetVariable
-		//   }
-		//
-		//   a = 1;
-		//   if (true) {
-		//     var a = 2; <-- do not reuse: BindVariable
-		//   }
-
-		state.stack.SetVariable(this.typeGatedMlrvalName.Name, rvalue)
+		if this.frameBind {
+			state.stack.BindVariable(this.typeGatedMlrvalName.Name, rvalue)
+		} else {
+			state.stack.SetVariable(this.typeGatedMlrvalName.Name, rvalue)
+		}
 		return nil
 	} else {
 		// TODO: propagate error return
-		state.stack.SetVariableIndexed(this.typeGatedMlrvalName.Name, indices, rvalue)
+		if this.frameBind {
+			state.stack.BindVariableIndexed(this.typeGatedMlrvalName.Name, indices, rvalue)
+		} else {
+			state.stack.SetVariableIndexed(this.typeGatedMlrvalName.Name, indices, rvalue)
+		}
 		return nil
 	}
 }