Fixed panic when converting index ranges to string

abs-lang · Apr 4, 2020 · 05866fb · 05866fb
1 parent 47455ff
commit 05866fb
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Showing 2 changed files with 14 additions and 1 deletion.
diff --git a/ast/ast.go b/ast/ast.go
@@ -543,7 +543,18 @@ func (ie *IndexExpression) String() string {
 	out.WriteString("[")
 
 	if ie.IsRange {
-		out.WriteString(ie.Index.String() + ":" + ie.End.String())
+		start := ""
+
+		if ie.Index != nil {
+			start = ie.Index.String()
+		}
+
+		end := ""
+
+		if ie.End != nil {
+			end = ie.End.String()
+		}
+		out.WriteString(start + ":" + end)
 	} else {
 		out.WriteString(ie.Index.String())
 	}

diff --git a/evaluator/builtin_functions_test.go b/evaluator/builtin_functions_test.go
@@ -258,6 +258,8 @@ func TestStr(t *testing.T) {
 		{`1.str()`, "1"},
 		{`[1].str()`, "[1]"},
 		{`{"a": 10}.str()`, `{"a": 10}`},
+		{`f() {a[3:]}.str()`, `f() {(a[3:])}`},
+		{`f() {a[:3]}.str()`, `f() {(a[0:3])}`},
 	}
 
 	testBuiltinFunction(tests, t)