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path: root/src/pkg/go/printer/nodes.go
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Diffstat (limited to 'src/pkg/go/printer/nodes.go')
-rw-r--r--src/pkg/go/printer/nodes.go183
1 files changed, 136 insertions, 47 deletions
diff --git a/src/pkg/go/printer/nodes.go b/src/pkg/go/printer/nodes.go
index 86c327930..0fca8a161 100644
--- a/src/pkg/go/printer/nodes.go
+++ b/src/pkg/go/printer/nodes.go
@@ -33,7 +33,7 @@ import (
// line break was printed; returns false otherwise.
//
// TODO(gri): linebreak may add too many lines if the next statement at "line"
-// is preceeded by comments because the computation of n assumes
+// is preceded by comments because the computation of n assumes
// the current position before the comment and the target position
// after the comment. Thus, after interspersing such comments, the
// space taken up by them is not considered to reduce the number of
@@ -215,12 +215,13 @@ func (p *printer) exprList(prev0 token.Pos, list []ast.Expr, depth int, mode exp
}
if i > 0 {
- if mode&commaSep != 0 {
+ switch {
+ case mode&commaSep != 0:
p.print(token.COMMA)
- }
- if mode&periodSep != 0 {
+ case mode&periodSep != 0:
p.print(token.PERIOD)
}
+ needsBlank := mode&periodSep == 0 // period-separated list elements don't need a blank
if prevLine < line && prevLine > 0 && line > 0 {
// lines are broken using newlines so comments remain aligned
// unless forceFF is set or there are multiple expressions on
@@ -229,11 +230,12 @@ func (p *printer) exprList(prev0 token.Pos, list []ast.Expr, depth int, mode exp
ws = ignore
*multiLine = true
prevBreak = i
+ needsBlank = false // we got a line break instead
}
- } else if mode&periodSep == 0 {
+ }
+ if needsBlank {
p.print(blank)
}
- // period-separated list elements don't need a blank
}
if isPair && size > 0 && len(list) > 1 {
@@ -438,8 +440,8 @@ func (p *printer) fieldList(fields *ast.FieldList, isStruct, isIncomplete bool)
if len(list) > 0 {
p.print(formfeed)
}
- p.flush(p.fset.Position(rbrace), token.RBRACE) // make sure we don't loose the last line comment
- p.setLineComment("// contains unexported fields")
+ p.flush(p.fset.Position(rbrace), token.RBRACE) // make sure we don't lose the last line comment
+ p.setLineComment("// contains filtered or unexported fields")
}
} else { // interface
@@ -465,8 +467,8 @@ func (p *printer) fieldList(fields *ast.FieldList, isStruct, isIncomplete bool)
if len(list) > 0 {
p.print(formfeed)
}
- p.flush(p.fset.Position(rbrace), token.RBRACE) // make sure we don't loose the last line comment
- p.setLineComment("// contains unexported methods")
+ p.flush(p.fset.Position(rbrace), token.RBRACE) // make sure we don't lose the last line comment
+ p.setLineComment("// contains filtered or unexported methods")
}
}
@@ -1189,6 +1191,97 @@ func (p *printer) stmt(stmt ast.Stmt, nextIsRBrace bool, multiLine *bool) {
// ----------------------------------------------------------------------------
// Declarations
+// The keepTypeColumn function determines if the type column of a series of
+// consecutive const or var declarations must be kept, or if initialization
+// values (V) can be placed in the type column (T) instead. The i'th entry
+// in the result slice is true if the type column in spec[i] must be kept.
+//
+// For example, the declaration:
+//
+// const (
+// foobar int = 42 // comment
+// x = 7 // comment
+// foo
+// bar = 991
+// )
+//
+// leads to the type/values matrix below. A run of value columns (V) can
+// be moved into the type column if there is no type for any of the values
+// in that column (we only move entire columns so that they align properly).
+//
+// matrix formatted result
+// matrix
+// T V -> T V -> true there is a T and so the type
+// - V - V true column must be kept
+// - - - - false
+// - V V - false V is moved into T column
+//
+func keepTypeColumn(specs []ast.Spec) []bool {
+ m := make([]bool, len(specs))
+
+ populate := func(i, j int, keepType bool) {
+ if keepType {
+ for ; i < j; i++ {
+ m[i] = true
+ }
+ }
+ }
+
+ i0 := -1 // if i0 >= 0 we are in a run and i0 is the start of the run
+ var keepType bool
+ for i, s := range specs {
+ t := s.(*ast.ValueSpec)
+ if t.Values != nil {
+ if i0 < 0 {
+ // start of a run of ValueSpecs with non-nil Values
+ i0 = i
+ keepType = false
+ }
+ } else {
+ if i0 >= 0 {
+ // end of a run
+ populate(i0, i, keepType)
+ i0 = -1
+ }
+ }
+ if t.Type != nil {
+ keepType = true
+ }
+ }
+ if i0 >= 0 {
+ // end of a run
+ populate(i0, len(specs), keepType)
+ }
+
+ return m
+}
+
+
+func (p *printer) valueSpec(s *ast.ValueSpec, keepType, doIndent bool, multiLine *bool) {
+ p.setComment(s.Doc)
+ p.identList(s.Names, doIndent, multiLine) // always present
+ extraTabs := 3
+ if s.Type != nil || keepType {
+ p.print(vtab)
+ extraTabs--
+ }
+ if s.Type != nil {
+ p.expr(s.Type, multiLine)
+ }
+ if s.Values != nil {
+ p.print(vtab, token.ASSIGN)
+ p.exprList(token.NoPos, s.Values, 1, blankStart|commaSep, multiLine, token.NoPos)
+ extraTabs--
+ }
+ if s.Comment != nil {
+ for ; extraTabs > 0; extraTabs-- {
+ p.print(vtab)
+ }
+ p.setComment(s.Comment)
+ }
+}
+
+
// The parameter n is the number of specs in the group. If doIndent is set,
// multi-line identifier lists in the spec are indented when the first
// linebreak is encountered.
@@ -1206,38 +1299,20 @@ func (p *printer) spec(spec ast.Spec, n int, doIndent bool, multiLine *bool) {
p.setComment(s.Comment)
case *ast.ValueSpec:
+ if n != 1 {
+ p.internalError("expected n = 1; got", n)
+ }
p.setComment(s.Doc)
p.identList(s.Names, doIndent, multiLine) // always present
- if n == 1 {
- if s.Type != nil {
- p.print(blank)
- p.expr(s.Type, multiLine)
- }
- if s.Values != nil {
- p.print(blank, token.ASSIGN)
- p.exprList(token.NoPos, s.Values, 1, blankStart|commaSep, multiLine, token.NoPos)
- }
- p.setComment(s.Comment)
-
- } else {
- extraTabs := 3
- if s.Type != nil {
- p.print(vtab)
- p.expr(s.Type, multiLine)
- extraTabs--
- }
- if s.Values != nil {
- p.print(vtab, token.ASSIGN)
- p.exprList(token.NoPos, s.Values, 1, blankStart|commaSep, multiLine, token.NoPos)
- extraTabs--
- }
- if s.Comment != nil {
- for ; extraTabs > 0; extraTabs-- {
- p.print(vtab)
- }
- p.setComment(s.Comment)
- }
+ if s.Type != nil {
+ p.print(blank)
+ p.expr(s.Type, multiLine)
+ }
+ if s.Values != nil {
+ p.print(blank, token.ASSIGN)
+ p.exprList(token.NoPos, s.Values, 1, blankStart|commaSep, multiLine, token.NoPos)
}
+ p.setComment(s.Comment)
case *ast.TypeSpec:
p.setComment(s.Doc)
@@ -1264,15 +1339,29 @@ func (p *printer) genDecl(d *ast.GenDecl, multiLine *bool) {
if d.Lparen.IsValid() {
// group of parenthesized declarations
p.print(d.Lparen, token.LPAREN)
- if len(d.Specs) > 0 {
+ if n := len(d.Specs); n > 0 {
p.print(indent, formfeed)
- var ml bool
- for i, s := range d.Specs {
- if i > 0 {
- p.linebreak(p.fset.Position(s.Pos()).Line, 1, ignore, ml)
+ if n > 1 && (d.Tok == token.CONST || d.Tok == token.VAR) {
+ // two or more grouped const/var declarations:
+ // determine if the type column must be kept
+ keepType := keepTypeColumn(d.Specs)
+ var ml bool
+ for i, s := range d.Specs {
+ if i > 0 {
+ p.linebreak(p.fset.Position(s.Pos()).Line, 1, ignore, ml)
+ }
+ ml = false
+ p.valueSpec(s.(*ast.ValueSpec), keepType[i], false, &ml)
+ }
+ } else {
+ var ml bool
+ for i, s := range d.Specs {
+ if i > 0 {
+ p.linebreak(p.fset.Position(s.Pos()).Line, 1, ignore, ml)
+ }
+ ml = false
+ p.spec(s, n, false, &ml)
}
- ml = false
- p.spec(s, len(d.Specs), false, &ml)
}
p.print(unindent, formfeed)
*multiLine = true
@@ -1303,7 +1392,7 @@ func (p *printer) nodeSize(n ast.Node, maxSize int) (size int) {
size = maxSize + 1 // assume n doesn't fit
p.nodeSizes[n] = size
- // nodeSize computation must be indendent of particular
+ // nodeSize computation must be independent of particular
// style so that we always get the same decision; print
// in RawFormat
cfg := Config{Mode: RawFormat}
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-27 21:01:30 +0000