cue/errors: add more Position information
- adds Position convenience funtion
- key position is now sorted first
- add same unwrapping support Path'
Issue #52
Change-Id: I883e810de0131a7e10a467e0d53b0c513dbba351
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/2213
Reviewed-by: Marcel van Lohuizen <mpvl@google.com>
diff --git a/cue/errors.go b/cue/errors.go
index 0d415e8..8fce493 100644
--- a/cue/errors.go
+++ b/cue/errors.go
@@ -44,6 +44,8 @@
return e.n.Pos()
}
+func (e *nodeError) InputPositions() []token.Pos { return nil }
+
func (e *nodeError) Path() []string {
return e.path
}
@@ -71,7 +73,7 @@
return e.err.Pos()
}
-func (e *valueError) Positions() []token.Pos {
+func (e *valueError) InputPositions() []token.Pos {
return e.err.Positions()
}
diff --git a/cue/errors/errors.go b/cue/errors/errors.go
index e60e8c4..f512028 100644
--- a/cue/errors/errors.go
+++ b/cue/errors/errors.go
@@ -63,8 +63,15 @@
// Error is the common error message.
type Error interface {
+ // Position returns the primary position of an error. If multiple positions
+ // contribute equally, this reflects one of them.
Position() token.Pos
+ // InputPositions reports positions that contributed to an error, including
+ // the expressions resulting in the conflict, as well as values that were
+ // the input to this expression.
+ InputPositions() []token.Pos
+
// Error reports the error message without position information.
Error() string
@@ -77,16 +84,49 @@
Msg() (format string, args []interface{})
}
-// Path returns the path of an Error if err is of that type.
-func Path(err error) []string {
- e, ok := err.(Error)
- if !ok {
+// Positions returns all positions returned by an error, sorted
+// by relevance when possible and with duplicates removed.
+func Positions(err error) []token.Pos {
+ e := Error(nil)
+ if !xerrors.As(err, &e) {
return nil
}
- return e.Path()
+
+ a := make([]token.Pos, 0, 3)
+
+ sortOffset := 0
+ pos := e.Position()
+ if pos.IsValid() {
+ a = append(a, pos)
+ sortOffset = 1
+ }
+
+ for _, p := range e.InputPositions() {
+ if p.IsValid() && p != pos {
+ a = append(a, p)
+ }
+ }
+
+ byPos := byPos(a[sortOffset:])
+ sort.Sort(byPos)
+ k := unique.ToFront(byPos)
+ return a[:k+sortOffset]
}
-// // TODO: make Error an interface that returns a list of positions.
+type byPos []token.Pos
+
+func (s *byPos) Truncate(n int) { (*s) = (*s)[:n] }
+func (s byPos) Len() int { return len(s) }
+func (s byPos) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
+func (s byPos) Less(i, j int) bool { return comparePos(s[i], s[j]) == -1 }
+
+// Path returns the path of an Error if err is of that type.
+func Path(err error) []string {
+ if e := Error(nil); xerrors.As(err, &e) {
+ return e.Path()
+ }
+ return nil
+}
// Newf creates an Error with the associated position and message.
func Newf(p token.Pos, format string, args ...interface{}) Error {
@@ -124,6 +164,8 @@
return Path(p.err)
}
+func (p *posError) InputPositions() []token.Pos { return nil }
+
// E creates a new error.
func E(args ...interface{}) error {
e := &posError{}
@@ -237,26 +279,39 @@
func (p List) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
func (p List) Less(i, j int) bool {
- e := p[i].Position()
- f := p[j].Position()
+ if c := comparePos(p[i].Position(), p[j].Position()); c != 0 {
+ return c == -1
+ }
// Note that it is not sufficient to simply compare file offsets because
// the offsets do not reflect modified line information (through //line
// comments).
- if e.Filename() != f.Filename() {
- return e.Filename() < f.Filename()
- }
- if e.Line() != f.Line() {
- return e.Line() < f.Line()
- }
- if e.Column() != f.Column() {
- return e.Column() < f.Column()
- }
+
if !equalPath(p[i].Path(), p[j].Path()) {
return lessPath(p[i].Path(), p[j].Path())
}
return p[i].Error() < p[j].Error()
}
+func lessOrMore(isLess bool) int {
+ if isLess {
+ return -1
+ }
+ return 1
+}
+
+func comparePos(a, b token.Pos) int {
+ if a.Filename() != b.Filename() {
+ return lessOrMore(a.Filename() < b.Filename())
+ }
+ if a.Line() != b.Line() {
+ return lessOrMore(a.Line() < b.Line())
+ }
+ if a.Column() != b.Column() {
+ return lessOrMore(a.Column() < b.Column())
+ }
+ return 0
+}
+
func lessPath(a, b []string) bool {
for i, x := range a {
if i >= len(b) {
@@ -366,21 +421,8 @@
}
positions := []string{}
-
- for e := err; e != nil; e = xerrors.Unwrap(e) {
- switch x := e.(type) {
- case interface{ Positions() []token.Pos }:
- for _, p := range x.Positions() {
- if p.IsValid() {
- positions = append(positions, p.String())
- }
- }
-
- case interface{ Position() token.Pos }:
- if pos := x.Position().String(); pos != "-" {
- positions = append(positions, pos)
- }
- }
+ for _, p := range Positions(err) {
+ positions = append(positions, p.String())
}
if path := Path(err); path != nil {
@@ -392,8 +434,6 @@
return
}
- unique.Strings(&positions)
-
fprintf(w, "%v:\n", err)
for _, pos := range positions {
fprintf(w, " %s\n", pos)
diff --git a/cue/types.go b/cue/types.go
index 8ab4d11..c05ca61 100644
--- a/cue/types.go
+++ b/cue/types.go
@@ -167,8 +167,11 @@
}
func (e *marshalError) Path() []string { return e.err.Path() }
-func (e *marshalError) Position() token.Pos { return e.err.Position() }
func (e *marshalError) Msg() (string, []interface{}) { return e.err.Msg() }
+func (e *marshalError) Position() token.Pos { return e.err.Position() }
+func (e *marshalError) InputPositions() []token.Pos {
+ return e.err.InputPositions()
+}
func unwrapJSONError(err error) errors.Error {
switch x := err.(type) {
