feat: return ExprSyntaxError instead of nil when expression parsing fails for namespaced functions

1 files changed, 23 insertions, 0 deletions

diff --git a/hclsyntax/expression.go b/hclsyntax/expression.go
index c4a353c..63bd24c 100644
--- a/hclsyntax/expression.go
+++ b/hclsyntax/expression.go
@@ -2013,3 +2013,26 @@ func (e *AnonSymbolExpr) Range() hcl.Range {
 func (e *AnonSymbolExpr) StartRange() hcl.Range {
 	return e.SrcRange
 }
+
+// ExprSyntaxError is a placeholder for an invalid expression that could not
+// be parsed due to syntax errors.
+type ExprSyntaxError struct {
+	Placeholder cty.Value
+	ParseDiags  hcl.Diagnostics
+}
+
+func (e *ExprSyntaxError) Value(ctx *hcl.EvalContext) (cty.Value, hcl.Diagnostics) {
+	return e.Placeholder, e.ParseDiags
+}
+
+func (e *ExprSyntaxError) walkChildNodes(w internalWalkFunc) {
+	// ExprSyntaxError is a leaf node in the tree
+}
+
+func (e *ExprSyntaxError) Range() hcl.Range {
+	return hcl.Range{}
+}
+
+func (e *ExprSyntaxError) StartRange() hcl.Range {
+	return hcl.Range{}
+}