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-rw-r--r--src/cmd/compile/internal/syntax/printer.go996
1 files changed, 996 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/syntax/printer.go b/src/cmd/compile/internal/syntax/printer.go
new file mode 100644
index 0000000..0385227
--- /dev/null
+++ b/src/cmd/compile/internal/syntax/printer.go
@@ -0,0 +1,996 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements printing of syntax trees in source format.
+
+package syntax
+
+import (
+ "bytes"
+ "fmt"
+ "io"
+ "strings"
+)
+
+// Form controls print formatting.
+type Form uint
+
+const (
+ _ Form = iota // default
+ LineForm // use spaces instead of linebreaks where possible
+ ShortForm // like LineForm but print "…" for non-empty function or composite literal bodies
+)
+
+// Fprint prints node x to w in the specified form.
+// It returns the number of bytes written, and whether there was an error.
+func Fprint(w io.Writer, x Node, form Form) (n int, err error) {
+ p := printer{
+ output: w,
+ form: form,
+ linebreaks: form == 0,
+ }
+
+ defer func() {
+ n = p.written
+ if e := recover(); e != nil {
+ err = e.(writeError).err // re-panics if it's not a writeError
+ }
+ }()
+
+ p.print(x)
+ p.flush(_EOF)
+
+ return
+}
+
+// String is a convenience function that prints n in ShortForm
+// and returns the printed string.
+func String(n Node) string {
+ var buf bytes.Buffer
+ _, err := Fprint(&buf, n, ShortForm)
+ if err != nil {
+ fmt.Fprintf(&buf, "<<< ERROR: %s", err)
+ }
+ return buf.String()
+}
+
+type ctrlSymbol int
+
+const (
+ none ctrlSymbol = iota
+ semi
+ blank
+ newline
+ indent
+ outdent
+ // comment
+ // eolComment
+)
+
+type whitespace struct {
+ last token
+ kind ctrlSymbol
+ //text string // comment text (possibly ""); valid if kind == comment
+}
+
+type printer struct {
+ output io.Writer
+ written int // number of bytes written
+ form Form
+ linebreaks bool // print linebreaks instead of semis
+
+ indent int // current indentation level
+ nlcount int // number of consecutive newlines
+
+ pending []whitespace // pending whitespace
+ lastTok token // last token (after any pending semi) processed by print
+}
+
+// write is a thin wrapper around p.output.Write
+// that takes care of accounting and error handling.
+func (p *printer) write(data []byte) {
+ n, err := p.output.Write(data)
+ p.written += n
+ if err != nil {
+ panic(writeError{err})
+ }
+}
+
+var (
+ tabBytes = []byte("\t\t\t\t\t\t\t\t")
+ newlineByte = []byte("\n")
+ blankByte = []byte(" ")
+)
+
+func (p *printer) writeBytes(data []byte) {
+ if len(data) == 0 {
+ panic("expected non-empty []byte")
+ }
+ if p.nlcount > 0 && p.indent > 0 {
+ // write indentation
+ n := p.indent
+ for n > len(tabBytes) {
+ p.write(tabBytes)
+ n -= len(tabBytes)
+ }
+ p.write(tabBytes[:n])
+ }
+ p.write(data)
+ p.nlcount = 0
+}
+
+func (p *printer) writeString(s string) {
+ p.writeBytes([]byte(s))
+}
+
+// If impliesSemi returns true for a non-blank line's final token tok,
+// a semicolon is automatically inserted. Vice versa, a semicolon may
+// be omitted in those cases.
+func impliesSemi(tok token) bool {
+ switch tok {
+ case _Name,
+ _Break, _Continue, _Fallthrough, _Return,
+ /*_Inc, _Dec,*/ _Rparen, _Rbrack, _Rbrace: // TODO(gri) fix this
+ return true
+ }
+ return false
+}
+
+// TODO(gri) provide table of []byte values for all tokens to avoid repeated string conversion
+
+func lineComment(text string) bool {
+ return strings.HasPrefix(text, "//")
+}
+
+func (p *printer) addWhitespace(kind ctrlSymbol, text string) {
+ p.pending = append(p.pending, whitespace{p.lastTok, kind /*text*/})
+ switch kind {
+ case semi:
+ p.lastTok = _Semi
+ case newline:
+ p.lastTok = 0
+ // TODO(gri) do we need to handle /*-style comments containing newlines here?
+ }
+}
+
+func (p *printer) flush(next token) {
+ // eliminate semis and redundant whitespace
+ sawNewline := next == _EOF
+ sawParen := next == _Rparen || next == _Rbrace
+ for i := len(p.pending) - 1; i >= 0; i-- {
+ switch p.pending[i].kind {
+ case semi:
+ k := semi
+ if sawParen {
+ sawParen = false
+ k = none // eliminate semi
+ } else if sawNewline && impliesSemi(p.pending[i].last) {
+ sawNewline = false
+ k = none // eliminate semi
+ }
+ p.pending[i].kind = k
+ case newline:
+ sawNewline = true
+ case blank, indent, outdent:
+ // nothing to do
+ // case comment:
+ // // A multi-line comment acts like a newline; and a ""
+ // // comment implies by definition at least one newline.
+ // if text := p.pending[i].text; strings.HasPrefix(text, "/*") && strings.ContainsRune(text, '\n') {
+ // sawNewline = true
+ // }
+ // case eolComment:
+ // // TODO(gri) act depending on sawNewline
+ default:
+ panic("unreachable")
+ }
+ }
+
+ // print pending
+ prev := none
+ for i := range p.pending {
+ switch p.pending[i].kind {
+ case none:
+ // nothing to do
+ case semi:
+ p.writeString(";")
+ p.nlcount = 0
+ prev = semi
+ case blank:
+ if prev != blank {
+ // at most one blank
+ p.writeBytes(blankByte)
+ p.nlcount = 0
+ prev = blank
+ }
+ case newline:
+ const maxEmptyLines = 1
+ if p.nlcount <= maxEmptyLines {
+ p.write(newlineByte)
+ p.nlcount++
+ prev = newline
+ }
+ case indent:
+ p.indent++
+ case outdent:
+ p.indent--
+ if p.indent < 0 {
+ panic("negative indentation")
+ }
+ // case comment:
+ // if text := p.pending[i].text; text != "" {
+ // p.writeString(text)
+ // p.nlcount = 0
+ // prev = comment
+ // }
+ // // TODO(gri) should check that line comments are always followed by newline
+ default:
+ panic("unreachable")
+ }
+ }
+
+ p.pending = p.pending[:0] // re-use underlying array
+}
+
+func mayCombine(prev token, next byte) (b bool) {
+ return // for now
+ // switch prev {
+ // case lexical.Int:
+ // b = next == '.' // 1.
+ // case lexical.Add:
+ // b = next == '+' // ++
+ // case lexical.Sub:
+ // b = next == '-' // --
+ // case lexical.Quo:
+ // b = next == '*' // /*
+ // case lexical.Lss:
+ // b = next == '-' || next == '<' // <- or <<
+ // case lexical.And:
+ // b = next == '&' || next == '^' // && or &^
+ // }
+ // return
+}
+
+func (p *printer) print(args ...interface{}) {
+ for i := 0; i < len(args); i++ {
+ switch x := args[i].(type) {
+ case nil:
+ // we should not reach here but don't crash
+
+ case Node:
+ p.printNode(x)
+
+ case token:
+ // _Name implies an immediately following string
+ // argument which is the actual value to print.
+ var s string
+ if x == _Name {
+ i++
+ if i >= len(args) {
+ panic("missing string argument after _Name")
+ }
+ s = args[i].(string)
+ } else {
+ s = x.String()
+ }
+
+ // TODO(gri) This check seems at the wrong place since it doesn't
+ // take into account pending white space.
+ if mayCombine(p.lastTok, s[0]) {
+ panic("adjacent tokens combine without whitespace")
+ }
+
+ if x == _Semi {
+ // delay printing of semi
+ p.addWhitespace(semi, "")
+ } else {
+ p.flush(x)
+ p.writeString(s)
+ p.nlcount = 0
+ p.lastTok = x
+ }
+
+ case Operator:
+ if x != 0 {
+ p.flush(_Operator)
+ p.writeString(x.String())
+ }
+
+ case ctrlSymbol:
+ switch x {
+ case none, semi /*, comment*/ :
+ panic("unreachable")
+ case newline:
+ // TODO(gri) need to handle mandatory newlines after a //-style comment
+ if !p.linebreaks {
+ x = blank
+ }
+ }
+ p.addWhitespace(x, "")
+
+ // case *Comment: // comments are not Nodes
+ // p.addWhitespace(comment, x.Text)
+
+ default:
+ panic(fmt.Sprintf("unexpected argument %v (%T)", x, x))
+ }
+ }
+}
+
+func (p *printer) printNode(n Node) {
+ // ncom := *n.Comments()
+ // if ncom != nil {
+ // // TODO(gri) in general we cannot make assumptions about whether
+ // // a comment is a /*- or a //-style comment since the syntax
+ // // tree may have been manipulated. Need to make sure the correct
+ // // whitespace is emitted.
+ // for _, c := range ncom.Alone {
+ // p.print(c, newline)
+ // }
+ // for _, c := range ncom.Before {
+ // if c.Text == "" || lineComment(c.Text) {
+ // panic("unexpected empty line or //-style 'before' comment")
+ // }
+ // p.print(c, blank)
+ // }
+ // }
+
+ p.printRawNode(n)
+
+ // if ncom != nil && len(ncom.After) > 0 {
+ // for i, c := range ncom.After {
+ // if i+1 < len(ncom.After) {
+ // if c.Text == "" || lineComment(c.Text) {
+ // panic("unexpected empty line or //-style non-final 'after' comment")
+ // }
+ // }
+ // p.print(blank, c)
+ // }
+ // //p.print(newline)
+ // }
+}
+
+func (p *printer) printRawNode(n Node) {
+ switch n := n.(type) {
+ case nil:
+ // we should not reach here but don't crash
+
+ // expressions and types
+ case *BadExpr:
+ p.print(_Name, "<bad expr>")
+
+ case *Name:
+ p.print(_Name, n.Value) // _Name requires actual value following immediately
+
+ case *BasicLit:
+ p.print(_Name, n.Value) // _Name requires actual value following immediately
+
+ case *FuncLit:
+ p.print(n.Type, blank)
+ if n.Body != nil {
+ if p.form == ShortForm {
+ p.print(_Lbrace)
+ if len(n.Body.List) > 0 {
+ p.print(_Name, "…")
+ }
+ p.print(_Rbrace)
+ } else {
+ p.print(n.Body)
+ }
+ }
+
+ case *CompositeLit:
+ if n.Type != nil {
+ p.print(n.Type)
+ }
+ p.print(_Lbrace)
+ if p.form == ShortForm {
+ if len(n.ElemList) > 0 {
+ p.print(_Name, "…")
+ }
+ } else {
+ if n.NKeys > 0 && n.NKeys == len(n.ElemList) {
+ p.printExprLines(n.ElemList)
+ } else {
+ p.printExprList(n.ElemList)
+ }
+ }
+ p.print(_Rbrace)
+
+ case *ParenExpr:
+ p.print(_Lparen, n.X, _Rparen)
+
+ case *SelectorExpr:
+ p.print(n.X, _Dot, n.Sel)
+
+ case *IndexExpr:
+ p.print(n.X, _Lbrack, n.Index, _Rbrack)
+
+ case *SliceExpr:
+ p.print(n.X, _Lbrack)
+ if i := n.Index[0]; i != nil {
+ p.printNode(i)
+ }
+ p.print(_Colon)
+ if j := n.Index[1]; j != nil {
+ p.printNode(j)
+ }
+ if k := n.Index[2]; k != nil {
+ p.print(_Colon, k)
+ }
+ p.print(_Rbrack)
+
+ case *AssertExpr:
+ p.print(n.X, _Dot, _Lparen, n.Type, _Rparen)
+
+ case *TypeSwitchGuard:
+ if n.Lhs != nil {
+ p.print(n.Lhs, blank, _Define, blank)
+ }
+ p.print(n.X, _Dot, _Lparen, _Type, _Rparen)
+
+ case *CallExpr:
+ p.print(n.Fun, _Lparen)
+ p.printExprList(n.ArgList)
+ if n.HasDots {
+ p.print(_DotDotDot)
+ }
+ p.print(_Rparen)
+
+ case *Operation:
+ if n.Y == nil {
+ // unary expr
+ p.print(n.Op)
+ // if n.Op == lexical.Range {
+ // p.print(blank)
+ // }
+ p.print(n.X)
+ } else {
+ // binary expr
+ // TODO(gri) eventually take precedence into account
+ // to control possibly missing parentheses
+ p.print(n.X, blank, n.Op, blank, n.Y)
+ }
+
+ case *KeyValueExpr:
+ p.print(n.Key, _Colon, blank, n.Value)
+
+ case *ListExpr:
+ p.printExprList(n.ElemList)
+
+ case *ArrayType:
+ var len interface{} = _DotDotDot
+ if n.Len != nil {
+ len = n.Len
+ }
+ p.print(_Lbrack, len, _Rbrack, n.Elem)
+
+ case *SliceType:
+ p.print(_Lbrack, _Rbrack, n.Elem)
+
+ case *DotsType:
+ p.print(_DotDotDot, n.Elem)
+
+ case *StructType:
+ p.print(_Struct)
+ if len(n.FieldList) > 0 && p.linebreaks {
+ p.print(blank)
+ }
+ p.print(_Lbrace)
+ if len(n.FieldList) > 0 {
+ if p.linebreaks {
+ p.print(newline, indent)
+ p.printFieldList(n.FieldList, n.TagList, _Semi)
+ p.print(outdent, newline)
+ } else {
+ p.printFieldList(n.FieldList, n.TagList, _Semi)
+ }
+ }
+ p.print(_Rbrace)
+
+ case *FuncType:
+ p.print(_Func)
+ p.printSignature(n)
+
+ case *InterfaceType:
+ p.print(_Interface)
+ if p.linebreaks && len(n.MethodList) > 1 {
+ p.print(blank)
+ p.print(_Lbrace)
+ p.print(newline, indent)
+ p.printMethodList(n.MethodList)
+ p.print(outdent, newline)
+ } else {
+ p.print(_Lbrace)
+ p.printMethodList(n.MethodList)
+ }
+ p.print(_Rbrace)
+
+ case *MapType:
+ p.print(_Map, _Lbrack, n.Key, _Rbrack, n.Value)
+
+ case *ChanType:
+ if n.Dir == RecvOnly {
+ p.print(_Arrow)
+ }
+ p.print(_Chan)
+ if n.Dir == SendOnly {
+ p.print(_Arrow)
+ }
+ p.print(blank)
+ if e, _ := n.Elem.(*ChanType); n.Dir == 0 && e != nil && e.Dir == RecvOnly {
+ // don't print chan (<-chan T) as chan <-chan T
+ p.print(_Lparen)
+ p.print(n.Elem)
+ p.print(_Rparen)
+ } else {
+ p.print(n.Elem)
+ }
+
+ // statements
+ case *DeclStmt:
+ p.printDecl(n.DeclList)
+
+ case *EmptyStmt:
+ // nothing to print
+
+ case *LabeledStmt:
+ p.print(outdent, n.Label, _Colon, indent, newline, n.Stmt)
+
+ case *ExprStmt:
+ p.print(n.X)
+
+ case *SendStmt:
+ p.print(n.Chan, blank, _Arrow, blank, n.Value)
+
+ case *AssignStmt:
+ p.print(n.Lhs)
+ if n.Rhs == nil {
+ // TODO(gri) This is going to break the mayCombine
+ // check once we enable that again.
+ p.print(n.Op, n.Op) // ++ or --
+ } else {
+ p.print(blank, n.Op, _Assign, blank)
+ p.print(n.Rhs)
+ }
+
+ case *CallStmt:
+ p.print(n.Tok, blank, n.Call)
+
+ case *ReturnStmt:
+ p.print(_Return)
+ if n.Results != nil {
+ p.print(blank, n.Results)
+ }
+
+ case *BranchStmt:
+ p.print(n.Tok)
+ if n.Label != nil {
+ p.print(blank, n.Label)
+ }
+
+ case *BlockStmt:
+ p.print(_Lbrace)
+ if len(n.List) > 0 {
+ p.print(newline, indent)
+ p.printStmtList(n.List, true)
+ p.print(outdent, newline)
+ }
+ p.print(_Rbrace)
+
+ case *IfStmt:
+ p.print(_If, blank)
+ if n.Init != nil {
+ p.print(n.Init, _Semi, blank)
+ }
+ p.print(n.Cond, blank, n.Then)
+ if n.Else != nil {
+ p.print(blank, _Else, blank, n.Else)
+ }
+
+ case *SwitchStmt:
+ p.print(_Switch, blank)
+ if n.Init != nil {
+ p.print(n.Init, _Semi, blank)
+ }
+ if n.Tag != nil {
+ p.print(n.Tag, blank)
+ }
+ p.printSwitchBody(n.Body)
+
+ case *SelectStmt:
+ p.print(_Select, blank) // for now
+ p.printSelectBody(n.Body)
+
+ case *RangeClause:
+ if n.Lhs != nil {
+ tok := _Assign
+ if n.Def {
+ tok = _Define
+ }
+ p.print(n.Lhs, blank, tok, blank)
+ }
+ p.print(_Range, blank, n.X)
+
+ case *ForStmt:
+ p.print(_For, blank)
+ if n.Init == nil && n.Post == nil {
+ if n.Cond != nil {
+ p.print(n.Cond, blank)
+ }
+ } else {
+ if n.Init != nil {
+ p.print(n.Init)
+ // TODO(gri) clean this up
+ if _, ok := n.Init.(*RangeClause); ok {
+ p.print(blank, n.Body)
+ break
+ }
+ }
+ p.print(_Semi, blank)
+ if n.Cond != nil {
+ p.print(n.Cond)
+ }
+ p.print(_Semi, blank)
+ if n.Post != nil {
+ p.print(n.Post, blank)
+ }
+ }
+ p.print(n.Body)
+
+ case *ImportDecl:
+ if n.Group == nil {
+ p.print(_Import, blank)
+ }
+ if n.LocalPkgName != nil {
+ p.print(n.LocalPkgName, blank)
+ }
+ p.print(n.Path)
+
+ case *ConstDecl:
+ if n.Group == nil {
+ p.print(_Const, blank)
+ }
+ p.printNameList(n.NameList)
+ if n.Type != nil {
+ p.print(blank, n.Type)
+ }
+ if n.Values != nil {
+ p.print(blank, _Assign, blank, n.Values)
+ }
+
+ case *TypeDecl:
+ if n.Group == nil {
+ p.print(_Type, blank)
+ }
+ p.print(n.Name)
+ if n.TParamList != nil {
+ p.printParameterList(n.TParamList, true)
+ }
+ p.print(blank)
+ if n.Alias {
+ p.print(_Assign, blank)
+ }
+ p.print(n.Type)
+
+ case *VarDecl:
+ if n.Group == nil {
+ p.print(_Var, blank)
+ }
+ p.printNameList(n.NameList)
+ if n.Type != nil {
+ p.print(blank, n.Type)
+ }
+ if n.Values != nil {
+ p.print(blank, _Assign, blank, n.Values)
+ }
+
+ case *FuncDecl:
+ p.print(_Func, blank)
+ if r := n.Recv; r != nil {
+ p.print(_Lparen)
+ if r.Name != nil {
+ p.print(r.Name, blank)
+ }
+ p.printNode(r.Type)
+ p.print(_Rparen, blank)
+ }
+ p.print(n.Name)
+ if n.TParamList != nil {
+ p.printParameterList(n.TParamList, true)
+ }
+ p.printSignature(n.Type)
+ if n.Body != nil {
+ p.print(blank, n.Body)
+ }
+
+ case *printGroup:
+ p.print(n.Tok, blank, _Lparen)
+ if len(n.Decls) > 0 {
+ p.print(newline, indent)
+ for _, d := range n.Decls {
+ p.printNode(d)
+ p.print(_Semi, newline)
+ }
+ p.print(outdent)
+ }
+ p.print(_Rparen)
+
+ // files
+ case *File:
+ p.print(_Package, blank, n.PkgName)
+ if len(n.DeclList) > 0 {
+ p.print(_Semi, newline, newline)
+ p.printDeclList(n.DeclList)
+ }
+
+ default:
+ panic(fmt.Sprintf("syntax.Iterate: unexpected node type %T", n))
+ }
+}
+
+func (p *printer) printFields(fields []*Field, tags []*BasicLit, i, j int) {
+ if i+1 == j && fields[i].Name == nil {
+ // anonymous field
+ p.printNode(fields[i].Type)
+ } else {
+ for k, f := range fields[i:j] {
+ if k > 0 {
+ p.print(_Comma, blank)
+ }
+ p.printNode(f.Name)
+ }
+ p.print(blank)
+ p.printNode(fields[i].Type)
+ }
+ if i < len(tags) && tags[i] != nil {
+ p.print(blank)
+ p.printNode(tags[i])
+ }
+}
+
+func (p *printer) printFieldList(fields []*Field, tags []*BasicLit, sep token) {
+ i0 := 0
+ var typ Expr
+ for i, f := range fields {
+ if f.Name == nil || f.Type != typ {
+ if i0 < i {
+ p.printFields(fields, tags, i0, i)
+ p.print(sep, newline)
+ i0 = i
+ }
+ typ = f.Type
+ }
+ }
+ p.printFields(fields, tags, i0, len(fields))
+}
+
+func (p *printer) printMethodList(methods []*Field) {
+ for i, m := range methods {
+ if i > 0 {
+ p.print(_Semi, newline)
+ }
+ if m.Name != nil {
+ p.printNode(m.Name)
+ p.printSignature(m.Type.(*FuncType))
+ } else {
+ p.printNode(m.Type)
+ }
+ }
+}
+
+func (p *printer) printNameList(list []*Name) {
+ for i, x := range list {
+ if i > 0 {
+ p.print(_Comma, blank)
+ }
+ p.printNode(x)
+ }
+}
+
+func (p *printer) printExprList(list []Expr) {
+ for i, x := range list {
+ if i > 0 {
+ p.print(_Comma, blank)
+ }
+ p.printNode(x)
+ }
+}
+
+func (p *printer) printExprLines(list []Expr) {
+ if len(list) > 0 {
+ p.print(newline, indent)
+ for _, x := range list {
+ p.print(x, _Comma, newline)
+ }
+ p.print(outdent)
+ }
+}
+
+func groupFor(d Decl) (token, *Group) {
+ switch d := d.(type) {
+ case *ImportDecl:
+ return _Import, d.Group
+ case *ConstDecl:
+ return _Const, d.Group
+ case *TypeDecl:
+ return _Type, d.Group
+ case *VarDecl:
+ return _Var, d.Group
+ case *FuncDecl:
+ return _Func, nil
+ default:
+ panic("unreachable")
+ }
+}
+
+type printGroup struct {
+ node
+ Tok token
+ Decls []Decl
+}
+
+func (p *printer) printDecl(list []Decl) {
+ tok, group := groupFor(list[0])
+
+ if group == nil {
+ if len(list) != 1 {
+ panic("unreachable")
+ }
+ p.printNode(list[0])
+ return
+ }
+
+ // if _, ok := list[0].(*EmptyDecl); ok {
+ // if len(list) != 1 {
+ // panic("unreachable")
+ // }
+ // // TODO(gri) if there are comments inside the empty
+ // // group, we may need to keep the list non-nil
+ // list = nil
+ // }
+
+ // printGroup is here for consistent comment handling
+ // (this is not yet used)
+ var pg printGroup
+ // *pg.Comments() = *group.Comments()
+ pg.Tok = tok
+ pg.Decls = list
+ p.printNode(&pg)
+}
+
+func (p *printer) printDeclList(list []Decl) {
+ i0 := 0
+ var tok token
+ var group *Group
+ for i, x := range list {
+ if s, g := groupFor(x); g == nil || g != group {
+ if i0 < i {
+ p.printDecl(list[i0:i])
+ p.print(_Semi, newline)
+ // print empty line between different declaration groups,
+ // different kinds of declarations, or between functions
+ if g != group || s != tok || s == _Func {
+ p.print(newline)
+ }
+ i0 = i
+ }
+ tok, group = s, g
+ }
+ }
+ p.printDecl(list[i0:])
+}
+
+func (p *printer) printSignature(sig *FuncType) {
+ p.printParameterList(sig.ParamList, false)
+ if list := sig.ResultList; list != nil {
+ p.print(blank)
+ if len(list) == 1 && list[0].Name == nil {
+ p.printNode(list[0].Type)
+ } else {
+ p.printParameterList(list, false)
+ }
+ }
+}
+
+func (p *printer) printParameterList(list []*Field, types bool) {
+ open, close := _Lparen, _Rparen
+ if types {
+ open, close = _Lbrack, _Rbrack
+ }
+ p.print(open)
+ for i, f := range list {
+ if i > 0 {
+ p.print(_Comma, blank)
+ }
+ if f.Name != nil {
+ p.printNode(f.Name)
+ if i+1 < len(list) {
+ f1 := list[i+1]
+ if f1.Name != nil && f1.Type == f.Type {
+ continue // no need to print type
+ }
+ }
+ p.print(blank)
+ }
+ p.printNode(unparen(f.Type)) // no need for (extra) parentheses around parameter types
+ }
+ // A type parameter list [P *T] where T is not a type literal requires a comma as in [P *T,]
+ // so that it's not parsed as [P*T].
+ if types && len(list) == 1 {
+ if t, _ := list[0].Type.(*Operation); t != nil && t.Op == Mul && t.Y == nil && !isTypeLit(t.X) {
+ p.print(_Comma)
+ }
+ }
+ p.print(close)
+}
+
+func (p *printer) printStmtList(list []Stmt, braces bool) {
+ for i, x := range list {
+ p.print(x, _Semi)
+ if i+1 < len(list) {
+ p.print(newline)
+ } else if braces {
+ // Print an extra semicolon if the last statement is
+ // an empty statement and we are in a braced block
+ // because one semicolon is automatically removed.
+ if _, ok := x.(*EmptyStmt); ok {
+ p.print(x, _Semi)
+ }
+ }
+ }
+}
+
+func (p *printer) printSwitchBody(list []*CaseClause) {
+ p.print(_Lbrace)
+ if len(list) > 0 {
+ p.print(newline)
+ for i, c := range list {
+ p.printCaseClause(c, i+1 == len(list))
+ p.print(newline)
+ }
+ }
+ p.print(_Rbrace)
+}
+
+func (p *printer) printSelectBody(list []*CommClause) {
+ p.print(_Lbrace)
+ if len(list) > 0 {
+ p.print(newline)
+ for i, c := range list {
+ p.printCommClause(c, i+1 == len(list))
+ p.print(newline)
+ }
+ }
+ p.print(_Rbrace)
+}
+
+func (p *printer) printCaseClause(c *CaseClause, braces bool) {
+ if c.Cases != nil {
+ p.print(_Case, blank, c.Cases)
+ } else {
+ p.print(_Default)
+ }
+ p.print(_Colon)
+ if len(c.Body) > 0 {
+ p.print(newline, indent)
+ p.printStmtList(c.Body, braces)
+ p.print(outdent)
+ }
+}
+
+func (p *printer) printCommClause(c *CommClause, braces bool) {
+ if c.Comm != nil {
+ p.print(_Case, blank)
+ p.print(c.Comm)
+ } else {
+ p.print(_Default)
+ }
+ p.print(_Colon)
+ if len(c.Body) > 0 {
+ p.print(newline, indent)
+ p.printStmtList(c.Body, braces)
+ p.print(outdent)
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-28 20:46:45 +0000