golint: suggest `for range` when possible
for _ = range and for _, _ = range can be written as
for range instead.
Change-Id: I6d5e7aecce941260f4a4de294685f99d9ff48c09
GitHub-Last-Rev: 318343fa69fea5d2e580eabddefe6ef31802f79e
GitHub-Pull-Request: golang/lint#196
Reviewed-on: https://go-review.googlesource.com/96176
Reviewed-by: Alan Donovan <adonovan@google.com>
diff --git a/lint.go b/lint.go
index 946936e..cc6fef2 100644
--- a/lint.go
+++ b/lint.go
@@ -1084,20 +1084,25 @@
if !ok {
return true
}
- if rs.Value == nil {
- // for x = range m { ... }
- return true // single var form
- }
- if !isIdent(rs.Value, "_") {
- // for ?, y = range m { ... }
+
+ if isIdent(rs.Key, "_") && (rs.Value == nil || isIdent(rs.Value, "_")) {
+ p := f.errorf(rs.Key, 1, category("range-loop"), "should omit values from range; this loop is equivalent to `for range ...`")
+
+ newRS := *rs // shallow copy
+ newRS.Value = nil
+ newRS.Key = nil
+ p.ReplacementLine = f.firstLineOf(&newRS, rs)
+
return true
}
- p := f.errorf(rs.Value, 1, category("range-loop"), "should omit 2nd value from range; this loop is equivalent to `for %s %s range ...`", f.render(rs.Key), rs.Tok)
+ if isIdent(rs.Value, "_") {
+ p := f.errorf(rs.Value, 1, category("range-loop"), "should omit 2nd value from range; this loop is equivalent to `for %s %s range ...`", f.render(rs.Key), rs.Tok)
- newRS := *rs // shallow copy
- newRS.Value = nil
- p.ReplacementLine = f.firstLineOf(&newRS, rs)
+ newRS := *rs // shallow copy
+ newRS.Value = nil
+ p.ReplacementLine = f.firstLineOf(&newRS, rs)
+ }
return true
})
diff --git a/testdata/range.go b/testdata/range.go
index af36a82..1a6725e 100644
--- a/testdata/range.go
+++ b/testdata/range.go
@@ -16,6 +16,12 @@
for y, _ = range m { // MATCH /should omit 2nd value.*range.*equivalent.*for y = range/
}
+ for _ = range m { // MATCH /should omit values.*range.*equivalent.*for range/
+ }
+
+ for _, _ = range m { // MATCH /should omit values.*range.*equivalent.*for range/
+ }
+
// all OK:
for x := range m {
_ = x
