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Commit c048ee21 authored by Robert Griesemer's avatar Robert Griesemer
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- converted expr representation of ast into a new representation 

using interfaces properly => much cleaner code
- converted tracing code to use 'defer' statement
- next steps: convert rest of ast as well

R=r
OCL=24277
CL=24277
parent f9cc900a
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Showing with 718 additions and 526 deletions
usr/gri/pretty/ast.go
View file @ c048ee21
......@@ -17,8 +17,7 @@ type (
Type struct;
Block struct;
Lit struct;
Expr struct;
Expr interface;
Stat struct;
Decl struct;
)
......@@ -128,26 +127,6 @@ type Node struct {
}
// ----------------------------------------------------------------------------
// Literals
type Lit struct {
Node;
// Identifiers
Obj *Object;
// Constant literals
// Type literals
Len *Expr; // array length
Dir int; // channel direction
Key *Type; // receiver or map key type
Elt *Type; // array, map, channel, pointer element, or function result type
List *array.Array; End int; // struct fields, interface methods, function parameters
}
// ----------------------------------------------------------------------------
// Scopes
......@@ -218,87 +197,6 @@ func (scope *Scope) Print() {
}
// ----------------------------------------------------------------------------
// Blocks
//
// Syntactic constructs of the form:
//
// "{" StatementList "}"
// ":" StatementList
type Block struct {
Node;
List *array.Array;
End int; // position of closing "}" if present
}
func NewBlock(pos, tok int) *Block {
assert(tok == Scanner.LBRACE || tok == Scanner.COLON);
b := new(Block);
b.Pos, b.Tok, b.List = pos, tok, array.New(0);
return b;
}
// ----------------------------------------------------------------------------
// Expressions
type Expr struct {
Node;
X, Y *Expr; // binary (X, Y) and unary (Y) expressions
Obj *Object; // identifiers, literals
Typ *Type;
}
// Length of a comma-separated expression list.
func (x *Expr) Len() int {
if x == nil {
return 0;
}
n := 1;
for ; x.Tok == Scanner.COMMA; x = x.Y {
n++;
}
return n;
}
// The i'th expression in a comma-separated expression list.
func (x *Expr) At(i int) *Expr {
for j := 0; j < i; j++ {
assert(x.Tok == Scanner.COMMA);
x = x.Y;
}
if x.Tok == Scanner.COMMA {
x = x.X;
}
return x;
}
func NewExpr(pos, tok int, x, y *Expr) *Expr {
if x != nil && x.Tok == Scanner.TYPE || y != nil && y.Tok == Scanner.TYPE {
panic("no type expression allowed");
}
e := new(Expr);
e.Pos, e.Tok, e.X, e.Y = pos, tok, x, y;
return e;
}
// TODO probably don't need the tok parameter eventually
func NewLit(tok int, obj *Object) *Expr {
e := new(Expr);
e.Pos, e.Tok, e.Obj, e.Typ = obj.Pos, tok, obj, obj.Typ;
return e;
}
var BadExpr = NewExpr(0, Scanner.ILLEGAL, nil, nil);
// ----------------------------------------------------------------------------
// Types
......@@ -388,7 +286,7 @@ type Type struct {
// syntactic components
Pos int; // source position (< 0 if unknown position)
Expr *Expr; // type name, array length
Expr Expr; // type name, array length
Mode int; // channel mode
Key *Type; // receiver type or map key
Elt *Type; // type name type, array, map, channel or pointer element type, function result type
......@@ -411,25 +309,6 @@ func NewType(pos, form int) *Type {
}
func (t *Type) Nfields() int {
if t.List == nil {
return 0;
}
nx, nt := 0, 0;
for i, n := 0, t.List.Len(); i < n; i++ {
if t.List.At(i).(*Expr).Tok == Scanner.TYPE {
nt++;
} else {
nx++;
}
}
if nx == 0 {
return nt;
}
return nx;
}
func (typ* Type) String() string {
if typ != nil {
return
......@@ -441,31 +320,199 @@ func (typ* Type) String() string {
}
// requires complete Type.Pos access
func NewTypeExpr(typ *Type) *Expr {
e := new(Expr);
e.Pos, e.Tok, e.Typ = typ.Pos, Scanner.TYPE, typ;
return e;
var BadType = NewType(0, Scanner.ILLEGAL);
// ----------------------------------------------------------------------------
// Blocks
//
// Syntactic constructs of the form:
//
// "{" StatementList "}"
// ":" StatementList
type Block struct {
Node;
List *array.Array;
End int; // position of closing "}" if present
}
// requires complete Type.String access
func (x *Expr) String() string {
if x != nil {
return
"Expr(" +
Scanner.TokenString(x.Tok) + ", " +
x.X.String() + ", " +
x.Y.String() + ", " +
x.Obj.String() + ", " +
x.Typ.String() +
")";
func NewBlock(pos, tok int) *Block {
assert(tok == Scanner.LBRACE || tok == Scanner.COLON);
b := new(Block);
b.Pos, b.Tok, b.List = pos, tok, array.New(0);
return b;
}
// ----------------------------------------------------------------------------
// Expressions
type (
Visitor interface;
Expr interface {
Pos() int;
Visit(v Visitor);
};
BadExpr struct {
Pos_ int;
};
Ident struct {
Pos_ int;
Obj *Object;
};
BinaryExpr struct {
Pos_, Tok int;
X, Y Expr;
};
UnaryExpr struct {
Pos_, Tok int;
X Expr;
};
BasicLit struct {
Pos_, Tok int;
Val string
};
FunctionLit struct {
Pos_ int; // position of "func"
Typ *Type;
Body *Block;
};
CompositeLit struct {
Pos_ int; // position of "{"
Typ *Type;
Elts Expr;
};
TypeLit struct {
Typ *Type;
};
Selector struct {
Pos_ int; // position of "."
X Expr;
Sel *Ident;
};
TypeGuard struct {
Pos_ int; // position of "."
X Expr;
Typ *Type;
};
Index struct {
Pos_ int; // position of "["
X, I Expr;
};
Call struct {
Pos_ int; // position of "("
F, Args Expr
};
)
type Visitor interface {
DoBadExpr(x *BadExpr);
DoIdent(x *Ident);
DoBinaryExpr(x *BinaryExpr);
DoUnaryExpr(x *UnaryExpr);
DoBasicLit(x *BasicLit);
DoFunctionLit(x *FunctionLit);
DoCompositeLit(x *CompositeLit);
DoTypeLit(x *TypeLit);
DoSelector(x *Selector);
DoTypeGuard(x *TypeGuard);
DoIndex(x *Index);
DoCall(x *Call);
}
func (x *BadExpr) Pos() int { return x.Pos_; }
func (x *Ident) Pos() int { return x.Pos_; }
func (x *BinaryExpr) Pos() int { return x.Pos_; }
func (x *UnaryExpr) Pos() int { return x.Pos_; }
func (x *BasicLit) Pos() int { return x.Pos_; }
func (x *FunctionLit) Pos() int { return x.Pos_; }
func (x *CompositeLit) Pos() int { return x.Pos_; }
func (x *TypeLit) Pos() int { return x.Typ.Pos; }
func (x *Selector) Pos() int { return x.Pos_; }
func (x *TypeGuard) Pos() int { return x.Pos_; }
func (x *Index) Pos() int { return x.Pos_; }
func (x *Call) Pos() int { return x.Pos_; }
func (x *BadExpr) Visit(v Visitor) { v.DoBadExpr(x); }
func (x *Ident) Visit(v Visitor) { v.DoIdent(x); }
func (x *BinaryExpr) Visit(v Visitor) { v.DoBinaryExpr(x); }
func (x *UnaryExpr) Visit(v Visitor) { v.DoUnaryExpr(x); }
func (x *BasicLit) Visit(v Visitor) { v.DoBasicLit(x); }
func (x *FunctionLit) Visit(v Visitor) { v.DoFunctionLit(x); }
func (x *CompositeLit) Visit(v Visitor) { v.DoCompositeLit(x); }
func (x *TypeLit) Visit(v Visitor) { v.DoTypeLit(x); }
func (x *Selector) Visit(v Visitor) { v.DoSelector(x); }
func (x *TypeGuard) Visit(v Visitor) { v.DoTypeGuard(x); }
func (x *Index) Visit(v Visitor) { v.DoIndex(x); }
func (x *Call) Visit(v Visitor) { v.DoCall(x); }
// Length of a comma-separated expression list.
func ExprLen(x Expr) int {
if x == nil {
return 0;
}
return "nil";
n := 1;
for {
if p, ok := x.(*BinaryExpr); ok && p.Tok == Scanner.COMMA {
n++;
x = p.Y;
} else {
break;
}
}
return n;
}
var BadType = NewType(0, Scanner.ILLEGAL);
func ExprAt(x Expr, i int) Expr {
for j := 0; j < i; j++ {
assert(x.(*BinaryExpr).Tok == Scanner.COMMA);
x = x.(*BinaryExpr).Y;
}
if t, is_binary := x.(*BinaryExpr); is_binary && t.Tok == Scanner.COMMA {
x = t.X;
}
return x;
}
func (t *Type) Nfields() int {
if t.List == nil {
return 0;
}
nx, nt := 0, 0;
for i, n := 0, t.List.Len(); i < n; i++ {
if dummy, ok := t.List.At(i).(*TypeLit); ok {
nt++;
} else {
nx++;
}
}
if nx == 0 {
return nt;
}
return nx;
}
// ----------------------------------------------------------------------------
......@@ -474,7 +521,7 @@ var BadType = NewType(0, Scanner.ILLEGAL);
type Stat struct {
Node;
Init, Post *Stat;
Expr *Expr;
Expr Expr;
Body *Block; // composite statement body
Decl *Decl; // declaration statement
}
......@@ -495,9 +542,10 @@ var BadStat = NewStat(0, Scanner.ILLEGAL);
type Decl struct {
Node;
Ident *Expr; // nil for ()-style declarations
Ident Expr; // nil for ()-style declarations
Typ *Type;
Val *Expr;
Val Expr;
Body *Block;
// list of *Decl for ()-style declarations
List *array.Array; End int;
}
......@@ -531,7 +579,7 @@ func NewComment(pos int, text string) *Comment {
type Program struct {
Pos int; // tok is Scanner.PACKAGE
Ident *Expr;
Ident Expr;
Decls *array.Array;
Comments *array.Array;
}
......
usr/gri/pretty/compilation.go
View file @ c048ee21
......@@ -158,6 +158,8 @@ func fileExists(name string) bool {
func addDeps(globalset map [string] bool, wset *array.Array, src_file string, flags *Flags) {
panic();
/*
dummy, found := globalset[src_file];
if !found {
globalset[src_file] = true;
......@@ -198,6 +200,7 @@ func addDeps(globalset map [string] bool, wset *array.Array, src_file string, fl
print("\n\n");
}
}
*/
}
......
usr/gri/pretty/parser.go
View file @ c048ee21
......@@ -64,26 +64,22 @@ func assert(pred bool) {
func (P *Parser) PrintIndent() {
for i := P.indent; i > 0; i-- {
print(". ");
fmt.Printf(". ");
}
}
func (P *Parser) Trace(msg string) {
if P.verbose {
P.PrintIndent();
print(msg, " {\n");
}
P.indent++; // always check proper identation
fmt.Printf("%s {\n", msg);
P.indent++;
}
func (P *Parser) Ecart() {
P.indent--; // always check proper identation
if P.verbose {
P.indent--;
P.PrintIndent();
print("}\n");
}
fmt.Printf("}\n");
}
......@@ -105,7 +101,7 @@ func (P *Parser) Next0() {
case "{": s = "LBRACE";
case "}": s = "RBRACE";
}
print("[", P.pos, "] ", s, "\n");
fmt.Printf("[%d] %s\n", P.pos, s);
}
}
......@@ -171,13 +167,12 @@ func (P *Parser) CloseScope() {
}
func (P *Parser) DeclareInScope(scope *AST.Scope, x *AST.Expr, kind int, typ *AST.Type) {
func (P *Parser) DeclareInScope(scope *AST.Scope, x AST.Expr, kind int, typ *AST.Type) {
if P.scope_lev < 0 {
panic("cannot declare objects in other packages");
}
if x.Tok != Scanner.ILLEGAL { // ignore bad exprs
assert(x.Tok == Scanner.IDENT);
obj := x.Obj;
if ident, ok := x.(*AST.Ident); ok { // ignore bad exprs
obj := ident.Obj;
obj.Kind = kind;
obj.Typ = typ;
obj.Pnolev = P.scope_lev;
......@@ -196,47 +191,54 @@ func (P *Parser) DeclareInScope(scope *AST.Scope, x *AST.Expr, kind int, typ *AS
// Declare a comma-separated list of idents or a single ident.
func (P *Parser) Declare(p *AST.Expr, kind int, typ *AST.Type) {
for p.Tok == Scanner.COMMA {
func (P *Parser) Declare(x AST.Expr, kind int, typ *AST.Type) {
for {
p, ok := x.(*AST.BinaryExpr);
if ok && p.Tok == Scanner.COMMA {
P.DeclareInScope(P.top_scope, p.X, kind, typ);
p = p.Y;
x = p.Y;
} else {
break;
}
}
P.DeclareInScope(P.top_scope, p, kind, typ);
P.DeclareInScope(P.top_scope, x, kind, typ);
}
// ----------------------------------------------------------------------------
// AST support
func exprType(x *AST.Expr) *AST.Type {
var t *AST.Type;
if x.Tok == Scanner.TYPE {
t = x.Typ;
} else if x.Tok == Scanner.IDENT {
func exprType(x AST.Expr) *AST.Type {
var typ *AST.Type;
if t, is_type := x.(*AST.TypeLit); is_type {
typ = t.Typ
} else if t, is_ident := x.(*AST.Ident); is_ident {
// assume a type name
t = AST.NewType(x.Pos, AST.TYPENAME);
t.Expr = x;
} else if x.Tok == Scanner.PERIOD && x.Y != nil && exprType(x.X) != nil {
typ = AST.NewType(t.Pos(), AST.TYPENAME);
typ.Expr = x;
} else if t, is_selector := x.(*AST.Selector); is_selector && exprType(t.Sel) != nil {
// possibly a qualified (type) identifier
t = AST.NewType(x.Pos, AST.TYPENAME);
t.Expr = x;
typ = AST.NewType(t.Pos(), AST.TYPENAME);
typ.Expr = x;
}
return t;
return typ;
}
func (P *Parser) NoType(x *AST.Expr) *AST.Expr {
if x != nil && x.Tok == Scanner.TYPE {
P.Error(x.Pos, "expected expression, found type");
val := AST.NewObject(x.Pos, AST.NONE, "0");
x = AST.NewLit(Scanner.INT, val);
func (P *Parser) NoType(x AST.Expr) AST.Expr {
if x != nil {
lit, ok := x.(*AST.TypeLit);
if ok {
P.Error(lit.Typ.Pos, "expected expression, found type");
x = &AST.BasicLit{lit.Typ.Pos, Scanner.STRING, ""};
}
}
return x;
}
func (P *Parser) NewExpr(pos, tok int, x, y *AST.Expr) *AST.Expr {
return AST.NewExpr(pos, tok, P.NoType(x), P.NoType(y));
func (P *Parser) NewBinary(pos, tok int, x, y AST.Expr) *AST.BinaryExpr {
return &AST.BinaryExpr{pos, tok, P.NoType(x), P.NoType(y)};
}
......@@ -244,16 +246,18 @@ func (P *Parser) NewExpr(pos, tok int, x, y *AST.Expr) *AST.Expr {
// Common productions
func (P *Parser) TryType() *AST.Type;
func (P *Parser) ParseExpression(prec int) *AST.Expr;
func (P *Parser) ParseExpression(prec int) AST.Expr;
func (P *Parser) ParseStatement() *AST.Stat;
func (P *Parser) ParseDeclaration() *AST.Decl;
// If scope != nil, lookup identifier in scope. Otherwise create one.
func (P *Parser) ParseIdent(scope *AST.Scope) *AST.Expr {
func (P *Parser) ParseIdent(scope *AST.Scope) *AST.Ident {
if P.verbose {
P.Trace("Ident");
defer P.Ecart();
}
x := AST.BadExpr;
if P.tok == Scanner.IDENT {
var obj *AST.Object;
if scope != nil {
......@@ -264,41 +268,41 @@ func (P *Parser) ParseIdent(scope *AST.Scope) *AST.Expr {
} else {
assert(obj.Kind != AST.NONE);
}
x = AST.NewLit(Scanner.IDENT, obj);
x.Pos = P.pos; // override obj.pos (incorrect if object was looked up!)
x := &AST.Ident{P.pos, obj};
if P.verbose {
P.PrintIndent();
print("Ident = \"", P.val, "\"\n");
fmt.Printf("ident = \"%s\"\n", P.val);
}
P.Next();
} else {
P.Expect(Scanner.IDENT); // use Expect() error handling
return x;
}
P.Ecart();
return x;
P.Expect(Scanner.IDENT); // use Expect() error handling
return &AST.Ident{P.pos, nil};
}
func (P *Parser) ParseIdentList() *AST.Expr {
func (P *Parser) ParseIdentList() AST.Expr {
if P.verbose {
P.Trace("IdentList");
defer P.Ecart();
}
var last *AST.Expr;
x := P.ParseIdent(nil);
var last *AST.BinaryExpr;
var x AST.Expr = P.ParseIdent(nil);
for P.tok == Scanner.COMMA {
pos := P.pos;
P.Next();
y := P.ParseIdent(nil);
if last == nil {
x = P.NewExpr(pos, Scanner.COMMA, x, y);
last = x;
last = P.NewBinary(pos, Scanner.COMMA, x, y);
x = last;
} else {
last.Y = P.NewExpr(pos, Scanner.COMMA, last.Y, y);
last.Y = P.NewBinary(pos, Scanner.COMMA, last.Y, y);
last = last.Y;
}
}
P.Ecart();
return x;
}
......@@ -307,7 +311,10 @@ func (P *Parser) ParseIdentList() *AST.Expr {
// Types
func (P *Parser) ParseType() *AST.Type {
if P.verbose {
P.Trace("Type");
defer P.Ecart();
}
t := P.TryType();
if t == nil {
......@@ -315,56 +322,61 @@ func (P *Parser) ParseType() *AST.Type {
t = AST.BadType;
}
P.Ecart();
return t;
}
func (P *Parser) ParseVarType() *AST.Type {
if P.verbose {
P.Trace("VarType");
defer P.Ecart();
}
typ := P.ParseType();
P.Ecart();
return typ;
return P.ParseType();
}
func (P *Parser) ParseQualifiedIdent() *AST.Expr {
func (P *Parser) ParseQualifiedIdent() AST.Expr {
if P.verbose {
P.Trace("QualifiedIdent");
defer P.Ecart();
}
x := P.ParseIdent(P.top_scope);
var x AST.Expr = P.ParseIdent(P.top_scope);
for P.tok == Scanner.PERIOD {
pos := P.pos;
P.Next();
y := P.ParseIdent(nil);
x = P.NewExpr(pos, Scanner.PERIOD, x, y);
x = &AST.Selector{pos, x, y};
}
P.Ecart();
return x;
}
func (P *Parser) ParseTypeName() *AST.Type {
if P.verbose {
P.Trace("TypeName");
defer P.Ecart();
}
t := AST.NewType(P.pos, AST.TYPENAME);
t.Expr = P.ParseQualifiedIdent();
t.Elt = t.Expr.Typ;
P.Ecart();
return t;
}
func (P *Parser) ParseArrayType() *AST.Type {
if P.verbose {
P.Trace("ArrayType");
defer P.Ecart();
}
t := AST.NewType(P.pos, AST.ARRAY);
P.Expect(Scanner.LBRACK);
if P.tok == Scanner.ELLIPSIS {
t.Expr = P.NewExpr(P.pos, Scanner.ELLIPSIS, nil, nil);
t.Expr = P.NewBinary(P.pos, Scanner.ELLIPSIS, nil, nil);
P.Next();
} else if P.tok != Scanner.RBRACK {
t.Expr = P.ParseExpression(1);
......@@ -372,13 +384,15 @@ func (P *Parser) ParseArrayType() *AST.Type {
P.Expect(Scanner.RBRACK);
t.Elt = P.ParseType();
P.Ecart();
return t;
}
func (P *Parser) ParseChannelType() *AST.Type {
if P.verbose {
P.Trace("ChannelType");
defer P.Ecart();
}
t := AST.NewType(P.pos, AST.CHANNEL);
t.Mode = AST.FULL;
......@@ -395,7 +409,6 @@ func (P *Parser) ParseChannelType() *AST.Type {
}
t.Elt = P.ParseVarType();
P.Ecart();
return t;
}
......@@ -404,7 +417,7 @@ func (P *Parser) ParseVar(expect_ident bool) *AST.Type {
t := AST.BadType;
if expect_ident {
x := P.ParseIdent(nil);
t = AST.NewType(x.Pos, AST.TYPENAME);
t = AST.NewType(x.Pos(), AST.TYPENAME);
t.Expr = x;
} else if P.tok == Scanner.ELLIPSIS {
t = AST.NewType(P.pos, AST.ELLIPSIS);
......@@ -417,7 +430,10 @@ func (P *Parser) ParseVar(expect_ident bool) *AST.Type {
func (P *Parser) ParseVarList(list *array.Array, ellipsis_ok bool) {
if P.verbose {
P.Trace("VarList");
defer P.Ecart();
}
// assume a list of types
// (a list of identifiers looks like a list of type names)
......@@ -450,31 +466,34 @@ func (P *Parser) ParseVarList(list *array.Array, ellipsis_ok bool) {
// convert the type entries into identifiers
for i, n := i0, list.Len(); i < n; i++ {
t := list.At(i).(*AST.Type);
if t.Form == AST.TYPENAME && t.Expr.Tok == Scanner.IDENT {
list.Set(i, t.Expr);
} else {
list.Set(i, AST.BadExpr);
P.Error(t.Pos, "identifier expected");
if t.Form == AST.TYPENAME {
if ident, ok := t.Expr.(*AST.Ident); ok {
list.Set(i, ident);
continue;
}
}
list.Set(i, &AST.BadExpr{0});
P.Error(t.Pos, "identifier expected");
}
// add type
list.Push(AST.NewTypeExpr(typ));
list.Push(&AST.TypeLit{typ});
} else {
// all list entries are types
// convert all type entries into type expressions
for i, n := i0, list.Len(); i < n; i++ {
t := list.At(i).(*AST.Type);
list.Set(i, AST.NewTypeExpr(t));
list.Set(i, &AST.TypeLit{t});
}
}
P.Ecart();
}
func (P *Parser) ParseParameterList(ellipsis_ok bool) *array.Array {
if P.verbose {
P.Trace("ParameterList");
defer P.Ecart();
}
list := array.New(0);
P.ParseVarList(list, ellipsis_ok);
......@@ -483,13 +502,15 @@ func (P *Parser) ParseParameterList(ellipsis_ok bool) *array.Array {
P.ParseVarList(list, ellipsis_ok);
}
P.Ecart();
return list;
}
func (P *Parser) ParseParameters(ellipsis_ok bool) *AST.Type {
if P.verbose {
P.Trace("Parameters");
defer P.Ecart();
}
t := AST.NewType(P.pos, AST.STRUCT);
P.Expect(Scanner.LPAREN);
......@@ -499,13 +520,15 @@ func (P *Parser) ParseParameters(ellipsis_ok bool) *AST.Type {
t.End = P.pos;
P.Expect(Scanner.RPAREN);
P.Ecart();
return t;
}
func (P *Parser) ParseResultList() {
if P.verbose {
P.Trace("ResultList");
defer P.Ecart();
}
P.ParseType();
for P.tok == Scanner.COMMA {
......@@ -515,13 +538,14 @@ func (P *Parser) ParseResultList() {
if P.tok != Scanner.RPAREN {
P.ParseType();
}
P.Ecart();
}
func (P *Parser) ParseResult(ftyp *AST.Type) *AST.Type {
if P.verbose {
P.Trace("Result");
defer P.Ecart();
}
var t *AST.Type;
if P.tok == Scanner.LPAREN {
......@@ -531,12 +555,11 @@ func (P *Parser) ParseResult(ftyp *AST.Type) *AST.Type {
if typ != nil {
t = AST.NewType(P.pos, AST.STRUCT);
t.List = array.New(0);
t.List.Push(AST.NewTypeExpr(typ));
t.List.Push(&AST.TypeLit{typ});
t.End = P.pos;
}
}
P.Ecart();
return t;
}
......@@ -548,7 +571,10 @@ func (P *Parser) ParseResult(ftyp *AST.Type) *AST.Type {
// (params) (results)
func (P *Parser) ParseSignature() *AST.Type {
if P.verbose {
P.Trace("Signature");
defer P.Ecart();
}
P.OpenScope();
P.scope_lev++;
......@@ -562,35 +588,38 @@ func (P *Parser) ParseSignature() *AST.Type {
P.scope_lev--;
P.CloseScope();
P.Ecart();
return t;
}
func (P *Parser) ParseFunctionType() *AST.Type {
if P.verbose {
P.Trace("FunctionType");
defer P.Ecart();
}
P.Expect(Scanner.FUNC);
t := P.ParseSignature();
P.Ecart();
return t;
return P.ParseSignature();
}
func (P *Parser) ParseMethodSpec(list *array.Array) {
if P.verbose {
P.Trace("MethodDecl");
defer P.Ecart();
}
list.Push(P.ParseIdentList());
t := P.ParseSignature();
list.Push(AST.NewTypeExpr(t));
P.Ecart();
list.Push(&AST.TypeLit{t});
}
func (P *Parser) ParseInterfaceType() *AST.Type {
if P.verbose {
P.Trace("InterfaceType");
defer P.Ecart();
}
t := AST.NewType(P.pos, AST.INTERFACE);
P.Expect(Scanner.INTERFACE);
......@@ -613,13 +642,15 @@ func (P *Parser) ParseInterfaceType() *AST.Type {
P.Expect(Scanner.RBRACE);
}
P.Ecart();
return t;
}
func (P *Parser) ParseMapType() *AST.Type {
if P.verbose {
P.Trace("MapType");
defer P.Ecart();
}
t := AST.NewType(P.pos, AST.MAP);
P.Expect(Scanner.MAP);
......@@ -628,15 +659,17 @@ func (P *Parser) ParseMapType() *AST.Type {
P.Expect(Scanner.RBRACK);
t.Elt = P.ParseVarType();
P.Ecart();
return t;
}
func (P *Parser) ParseOperand() *AST.Expr
func (P *Parser) ParseOperand() AST.Expr
func (P *Parser) ParseStructType() *AST.Type {
if P.verbose {
P.Trace("StructType");
defer P.Ecart();
}
t := AST.NewType(P.pos, AST.STRUCT);
P.Expect(Scanner.STRUCT);
......@@ -664,32 +697,35 @@ func (P *Parser) ParseStructType() *AST.Type {
// enter fields into struct scope
for i, n := 0, t.List.Len(); i < n; i++ {
x := t.List.At(i).(*AST.Expr);
if x.Tok == Scanner.IDENT {
if x, ok := t.List.At(i).(*AST.Ident); ok {
P.DeclareInScope(t.Scope, x, AST.FIELD, nil);
}
}
}
P.Ecart();
return t;
}
func (P *Parser) ParsePointerType() *AST.Type {
if P.verbose {
P.Trace("PointerType");
defer P.Ecart();
}
t := AST.NewType(P.pos, AST.POINTER);
P.Expect(Scanner.MUL);
t.Elt = P.ParseType();
P.Ecart();
return t;
}
func (P *Parser) TryType() *AST.Type {
if P.verbose {
P.Trace("Type (try)");
defer P.Ecart();
}
t := AST.BadType;
switch P.tok {
......@@ -703,8 +739,6 @@ func (P *Parser) TryType() *AST.Type {
case Scanner.MUL: t = P.ParsePointerType();
default: t = nil; // no type found
}
P.Ecart();
return t;
}
......@@ -713,7 +747,10 @@ func (P *Parser) TryType() *AST.Type {
// Blocks
func (P *Parser) ParseStatementList(list *array.Array) {
if P.verbose {
P.Trace("StatementList");
defer P.Ecart();
}
for P.tok != Scanner.CASE && P.tok != Scanner.DEFAULT && P.tok != Scanner.RBRACE && P.tok != Scanner.EOF {
s := P.ParseStatement();
......@@ -734,13 +771,14 @@ func (P *Parser) ParseStatementList(list *array.Array) {
if P.tok != Scanner.CASE && P.tok != Scanner.DEFAULT && P.tok != Scanner.RBRACE && P.tok != Scanner.EOF {
P.Error(P.pos, "expected end of statement list (semicolon missing?)");
}
P.Ecart();
}
func (P *Parser) ParseBlock(ftyp *AST.Type, tok int) *AST.Block {
if P.verbose {
P.Trace("Block");
defer P.Ecart();
}
b := AST.NewBlock(P.pos, tok);
P.Expect(tok);
......@@ -753,8 +791,7 @@ func (P *Parser) ParseBlock(ftyp *AST.Type, tok int) *AST.Block {
}
if ftyp.List != nil {
for i, n := 0, ftyp.List.Len(); i < n; i++ {
x := ftyp.List.At(i).(*AST.Expr);
if x.Tok == Scanner.IDENT {
if x, ok := ftyp.List.At(i).(*AST.Ident); ok {
P.DeclareInScope(P.top_scope, x, AST.VAR, nil);
}
}
......@@ -770,7 +807,6 @@ func (P *Parser) ParseBlock(ftyp *AST.Type, tok int) *AST.Block {
P.opt_semi = true;
}
P.Ecart();
return b;
}
......@@ -778,8 +814,11 @@ func (P *Parser) ParseBlock(ftyp *AST.Type, tok int) *AST.Block {
// ----------------------------------------------------------------------------
// Expressions
func (P *Parser) ParseExpressionList() *AST.Expr {
func (P *Parser) ParseExpressionList() AST.Expr {
if P.verbose {
P.Trace("ExpressionList");
defer P.Ecart();
}
x := P.ParseExpression(1);
for first := true; P.tok == Scanner.COMMA; {
......@@ -787,111 +826,112 @@ func (P *Parser) ParseExpressionList() *AST.Expr {
P.Next();
y := P.ParseExpression(1);
if first {
x = P.NewExpr(pos, Scanner.COMMA, x, y);
x = P.NewBinary(pos, Scanner.COMMA, x, y);
first = false;
} else {
x.Y = P.NewExpr(pos, Scanner.COMMA, x.Y, y);
x.(*AST.BinaryExpr).Y = P.NewBinary(pos, Scanner.COMMA, x.(*AST.BinaryExpr).Y, y);
}
}
P.Ecart();
return x;
}
func (P *Parser) ParseFunctionLit() *AST.Expr {
func (P *Parser) ParseFunctionLit() AST.Expr {
if P.verbose {
P.Trace("FunctionLit");
defer P.Ecart();
}
f := AST.NewObject(P.pos, AST.FUNC, "");
pos := P.pos;
P.Expect(Scanner.FUNC);
f.Typ = P.ParseSignature();
typ := P.ParseSignature();
P.expr_lev++;
P.scope_lev++;
f.Body = P.ParseBlock(f.Typ, Scanner.LBRACE);
body := P.ParseBlock(typ, Scanner.LBRACE);
P.scope_lev--;
P.expr_lev--;
P.Ecart();
return AST.NewLit(Scanner.FUNC, f);
return &AST.FunctionLit{pos, typ, body};
}
func (P *Parser) ParseOperand() *AST.Expr {
func (P *Parser) ParseOperand() AST.Expr {
if P.verbose {
P.Trace("Operand");
defer P.Ecart();
}
x := AST.BadExpr;
switch P.tok {
case Scanner.IDENT:
x = P.ParseIdent(P.top_scope);
return P.ParseIdent(P.top_scope);
case Scanner.LPAREN:
// TODO we could have a function type here as in: new(())
// (currently not working)
P.Next();
P.expr_lev++;
x = P.ParseExpression(1);
x := P.ParseExpression(1);
P.expr_lev--;
P.Expect(Scanner.RPAREN);
return x;
case Scanner.INT, Scanner.FLOAT, Scanner.STRING:
val := AST.NewObject(P.pos, AST.NONE, P.val);
x = AST.NewLit(P.tok, val);
x := &AST.BasicLit{P.pos, P.tok, P.val};
P.Next();
if x.Tok == Scanner.STRING {
// TODO should remember the list instead of
// concatenate the strings here
for ; P.tok == Scanner.STRING; P.Next() {
x.Obj.Ident += P.val;
x.Val += P.val;
}
}
return x;
case Scanner.FUNC:
x = P.ParseFunctionLit();
return P.ParseFunctionLit();
default:
t := P.TryType();
if t != nil {
x = AST.NewTypeExpr(t);
return &AST.TypeLit{t};
} else {
P.Error(P.pos, "operand expected");
P.Next(); // make progress
}
}
P.Ecart();
return x;
return &AST.BadExpr{P.pos};
}
func (P *Parser) ParseSelectorOrTypeGuard(x *AST.Expr) *AST.Expr {
func (P *Parser) ParseSelectorOrTypeGuard(x AST.Expr) AST.Expr {
if P.verbose {
P.Trace("SelectorOrTypeGuard");
defer P.Ecart();
}
x = P.NewExpr(P.pos, Scanner.PERIOD, x, nil);
pos := P.pos;
P.Expect(Scanner.PERIOD);
if P.tok == Scanner.IDENT {
// TODO should always guarantee x.Typ != nil
var scope *AST.Scope;
if x.X.Typ != nil {
scope = x.X.Typ.Scope;
}
x.Y = P.ParseIdent(scope);
x.Typ = x.Y.Obj.Typ;
x = &AST.Selector{pos, x, P.ParseIdent(nil)};
} else {
P.Expect(Scanner.LPAREN);
x.Y = AST.NewTypeExpr(P.ParseType());
x.Typ = x.Y.Typ;
x = &AST.TypeGuard{pos, x, P.ParseType()};
P.Expect(Scanner.RPAREN);
}
P.Ecart();
return x;
}
func (P *Parser) ParseIndex(x *AST.Expr) *AST.Expr {
func (P *Parser) ParseIndex(x AST.Expr) AST.Expr {
if P.verbose {
P.Trace("IndexOrSlice");
defer P.Ecart();
}
pos := P.pos;
P.Expect(Scanner.LBRACK);
......@@ -900,51 +940,51 @@ func (P *Parser) ParseIndex(x *AST.Expr) *AST.Expr {
P.expr_lev--;
P.Expect(Scanner.RBRACK);
P.Ecart();
return P.NewExpr(pos, Scanner.LBRACK, x, i);
return &AST.Index{pos, x, i};
}
func (P *Parser) ParseBinaryExpr(prec1 int) *AST.Expr
func (P *Parser) ParseBinaryExpr(prec1 int) AST.Expr
func (P *Parser) ParseCall(x0 *AST.Expr) *AST.Expr {
func (P *Parser) ParseCall(f AST.Expr) AST.Expr {
if P.verbose {
P.Trace("Call");
defer P.Ecart();
}
x := P.NewExpr(P.pos, Scanner.LPAREN, x0, nil);
call := &AST.Call{P.pos, f, nil};
P.Expect(Scanner.LPAREN);
if P.tok != Scanner.RPAREN {
P.expr_lev++;
var t *AST.Type;
if x0.Tok == Scanner.IDENT && (x0.Obj.Ident == "new" || x0.Obj.Ident == "make") {
if x0, ok := f.(*AST.Ident); ok && (x0.Obj.Ident == "new" || x0.Obj.Ident == "make") {
// heuristic: assume it's a new(T) or make(T, ...) call, try to parse a type
t = P.TryType();
}
if t != nil {
// we found a type
x.Y = AST.NewTypeExpr(t);
args := &AST.TypeLit{t};
if P.tok == Scanner.COMMA {
pos := P.pos;
P.Next();
y := P.ParseExpressionList();
// create list manually because NewExpr checks for type expressions
z := AST.NewExpr(pos, Scanner.COMMA, nil, y);
z.X = x.Y;
x.Y = z;
args := &AST.BinaryExpr{pos, Scanner.COMMA, args, y};
}
call.Args = args;
} else {
// normal argument list
x.Y = P.ParseExpressionList();
call.Args = P.ParseExpressionList();
}
P.expr_lev--;
}
P.Expect(Scanner.RPAREN);
P.Ecart();
return x;
return call;
}
func (P *Parser) ParseCompositeElements() *AST.Expr {
func (P *Parser) ParseCompositeElements() AST.Expr {
x := P.ParseExpression(0);
if P.tok == Scanner.COMMA {
pos := P.pos;
......@@ -952,29 +992,29 @@ func (P *Parser) ParseCompositeElements() *AST.Expr {
// first element determines mode
singles := true;
if x.Tok == Scanner.COLON {
if t, is_binary := x.(*AST.BinaryExpr); is_binary && t.Tok == Scanner.COLON {
singles = false;
}
var last *AST.Expr;
var last *AST.BinaryExpr;
for P.tok != Scanner.RBRACE && P.tok != Scanner.EOF {
y := P.ParseExpression(0);
if singles {
if y.Tok == Scanner.COLON {
P.Error(y.X.Pos, "single value expected; found pair");
if t, is_binary := y.(*AST.BinaryExpr); is_binary && t.Tok == Scanner.COLON {
P.Error(t.X.Pos(), "single value expected; found pair");
}
} else {
if y.Tok != Scanner.COLON {
P.Error(y.Pos, "key:value pair expected; found single value");
if t, is_binary := y.(*AST.BinaryExpr); !is_binary || t.Tok != Scanner.COLON {
P.Error(y.Pos(), "key:value pair expected; found single value");
}
}
if last == nil {
x = P.NewExpr(pos, Scanner.COMMA, x, y);
last = x;
last = P.NewBinary(pos, Scanner.COMMA, x, y);
x = last;
} else {
last.Y = P.NewExpr(pos, Scanner.COMMA, last.Y, y);
last.Y = P.NewBinary(pos, Scanner.COMMA, last.Y, y);
last = last.Y;
}
......@@ -991,25 +1031,29 @@ func (P *Parser) ParseCompositeElements() *AST.Expr {
}
func (P *Parser) ParseCompositeLit(t *AST.Type) *AST.Expr {
func (P *Parser) ParseCompositeLit(t *AST.Type) AST.Expr {
if P.verbose {
P.Trace("CompositeLit");
defer P.Ecart();
}
x := P.NewExpr(P.pos, Scanner.LBRACE, nil, nil);
x.Obj = AST.NewObject(t.Pos, AST.TYPE, "");
x.Obj.Typ = t;
pos := P.pos;
P.Expect(Scanner.LBRACE);
var elts AST.Expr;
if P.tok != Scanner.RBRACE {
x.Y = P.ParseCompositeElements();
elts = P.ParseCompositeElements();
}
P.Expect(Scanner.RBRACE);
P.Ecart();
return x;
return &AST.CompositeLit{pos, t, elts};
}
func (P *Parser) ParsePrimaryExpr() *AST.Expr {
func (P *Parser) ParsePrimaryExpr() AST.Expr {
if P.verbose {
P.Trace("PrimaryExpr");
defer P.Ecart();
}
x := P.ParseOperand();
for {
......@@ -1028,47 +1072,48 @@ func (P *Parser) ParsePrimaryExpr() *AST.Expr {
if t != nil {
x = P.ParseCompositeLit(t);
} else {
goto exit;
return x;
}
default: goto exit;
default:
return x;
}
}
exit:
P.Ecart();
return x;
unreachable();
return nil;
}
func (P *Parser) ParseUnaryExpr() *AST.Expr {
func (P *Parser) ParseUnaryExpr() AST.Expr {
if P.verbose {
P.Trace("UnaryExpr");
defer P.Ecart();
}
x := AST.BadExpr;
switch P.tok {
case Scanner.ADD, Scanner.SUB, Scanner.MUL, Scanner.NOT, Scanner.XOR, Scanner.ARROW, Scanner.AND:
pos, tok := P.pos, P.tok;
P.Next();
y := P.ParseUnaryExpr();
if tok == Scanner.MUL && y.Tok == Scanner.TYPE {
if lit, ok := y.(*AST.TypeLit); ok && tok == Scanner.MUL {
// pointer type
t := AST.NewType(pos, AST.POINTER);
t.Elt = y.Obj.Typ;
x = AST.NewTypeExpr(t);
t.Elt = lit.Typ;
return &AST.TypeLit{t};
} else {
x = P.NewExpr(pos, tok, nil, y);
return &AST.UnaryExpr{pos, tok, y};
}
default:
x = P.ParsePrimaryExpr();
}
P.Ecart();
return x;
return P.ParsePrimaryExpr();
}
func (P *Parser) ParseBinaryExpr(prec1 int) *AST.Expr {
func (P *Parser) ParseBinaryExpr(prec1 int) AST.Expr {
if P.verbose {
P.Trace("BinaryExpr");
defer P.Ecart();
}
x := P.ParseUnaryExpr();
for prec := Scanner.Precedence(P.tok); prec >= prec1; prec-- {
......@@ -1076,28 +1121,29 @@ func (P *Parser) ParseBinaryExpr(prec1 int) *AST.Expr {
pos, tok := P.pos, P.tok;
P.Next();
y := P.ParseBinaryExpr(prec + 1);
x = P.NewExpr(pos, tok, x, y);
x = P.NewBinary(pos, tok, x, y);
}
}
P.Ecart();
return x;
}
func (P *Parser) ParseExpression(prec int) *AST.Expr {
func (P *Parser) ParseExpression(prec int) AST.Expr {
if P.verbose {
P.Trace("Expression");
indent := P.indent;
defer P.Ecart();
}
indent := P.indent;
if prec < 0 {
panic("precedence must be >= 0");
}
x := P.NoType(P.ParseBinaryExpr(prec));
if indent != P.indent {
panic("imbalanced tracing code (Expression)");
}
P.Ecart();
return x;
}
......@@ -1106,31 +1152,21 @@ func (P *Parser) ParseExpression(prec int) *AST.Expr {
// Statements
func (P *Parser) ParseSimpleStat(range_ok bool) *AST.Stat {
if P.verbose {
P.Trace("SimpleStat");
defer P.Ecart();
}
s := AST.BadStat;
x := P.ParseExpressionList();
is_range := false;
if range_ok && P.tok == Scanner.COLON {
pos := P.pos;
P.Next();
y := P.ParseExpression(1);
if x.Len() == 1 {
x = P.NewExpr(pos, Scanner.COLON, x, y);
is_range = true;
} else {
P.Error(pos, "expected initialization, found ':'");
}
}
switch P.tok {
case Scanner.COLON:
// label declaration
s = AST.NewStat(P.pos, Scanner.COLON);
s.Expr = x;
if x.Len() != 1 {
P.Error(x.Pos, "illegal label declaration");
if AST.ExprLen(x) != 1 {
P.Error(x.Pos(), "illegal label declaration");
}
P.Next(); // consume ":"
P.opt_semi = true;
......@@ -1143,34 +1179,31 @@ func (P *Parser) ParseSimpleStat(range_ok bool) *AST.Stat {
// declaration/assignment
pos, tok := P.pos, P.tok;
P.Next();
y := AST.BadExpr;
var y AST.Expr = &AST.BadExpr{pos};
if P.tok == Scanner.RANGE {
range_pos := P.pos;
P.Next();
y = P.ParseExpression(1);
y = P.NewExpr(range_pos, Scanner.RANGE, nil, y);
y = P.NewBinary(range_pos, Scanner.RANGE, nil, y);
if tok != Scanner.DEFINE && tok != Scanner.ASSIGN {
P.Error(pos, "expected '=' or ':=', found '" + Scanner.TokenString(tok) + "'");
}
} else {
y = P.ParseExpressionList();
if is_range {
P.Error(y.Pos, "expected 'range', found expression");
}
if xl, yl := x.Len(), y.Len(); xl > 1 && yl > 1 && xl != yl {
P.Error(x.Pos, "arity of lhs doesn't match rhs");
if xl, yl := AST.ExprLen(x), AST.ExprLen(y); xl > 1 && yl > 1 && xl != yl {
P.Error(x.Pos(), "arity of lhs doesn't match rhs");
}
}
s = AST.NewStat(x.Pos, Scanner.EXPRSTAT);
s.Expr = AST.NewExpr(pos, tok, x, y);
s = AST.NewStat(x.Pos(), Scanner.EXPRSTAT);
s.Expr = P.NewBinary(pos, tok, x, y);
case Scanner.RANGE:
pos := P.pos;
P.Next();
y := P.ParseExpression(1);
y = P.NewExpr(pos, Scanner.RANGE, nil, y);
s = AST.NewStat(x.Pos, Scanner.EXPRSTAT);
s.Expr = AST.NewExpr(pos, Scanner.DEFINE, x, y);
y = &AST.UnaryExpr{pos, Scanner.RANGE, y};
s = AST.NewStat(x.Pos(), Scanner.EXPRSTAT);
s.Expr = P.NewBinary(pos, Scanner.DEFINE, x, y);
default:
var pos, tok int;
......@@ -1178,34 +1211,39 @@ func (P *Parser) ParseSimpleStat(range_ok bool) *AST.Stat {
pos, tok = P.pos, P.tok;
P.Next();
} else {
pos, tok = x.Pos, Scanner.EXPRSTAT;
pos, tok = x.Pos(), Scanner.EXPRSTAT;
}
s = AST.NewStat(pos, tok);
s.Expr = x;
if x.Len() != 1 {
P.Error(x.Pos, "only one expression allowed");
if AST.ExprLen(x) != 1 {
P.Error(pos, "only one expression allowed");
panic(); // fix position
}
}
P.Ecart();
return s;
}
func (P *Parser) ParseInvocationStat(keyword int) *AST.Stat {
if P.verbose {
P.Trace("InvocationStat");
defer P.Ecart();
}
s := AST.NewStat(P.pos, keyword);
P.Expect(keyword);
s.Expr = P.ParseExpression(1);
P.Ecart();
return s;
}
func (P *Parser) ParseReturnStat() *AST.Stat {
if P.verbose {
P.Trace("ReturnStat");
defer P.Ecart();
}
s := AST.NewStat(P.pos, Scanner.RETURN);
P.Expect(Scanner.RETURN);
......@@ -1213,13 +1251,15 @@ func (P *Parser) ParseReturnStat() *AST.Stat {
s.Expr = P.ParseExpressionList();
}
P.Ecart();
return s;
}
func (P *Parser) ParseControlFlowStat(tok int) *AST.Stat {
if P.verbose {
P.Trace("ControlFlowStat");
defer P.Ecart();
}
s := AST.NewStat(P.pos, tok);
P.Expect(tok);
......@@ -1227,13 +1267,15 @@ func (P *Parser) ParseControlFlowStat(tok int) *AST.Stat {
s.Expr = P.ParseIdent(P.top_scope);
}
P.Ecart();
return s;
}
func (P *Parser) ParseControlClause(keyword int) *AST.Stat {
if P.verbose {
P.Trace("ControlClause");
defer P.Ecart();
}
s := AST.NewStat(P.pos, keyword);
P.Expect(keyword);
......@@ -1263,13 +1305,15 @@ func (P *Parser) ParseControlClause(keyword int) *AST.Stat {
P.expr_lev = prev_lev;
}
P.Ecart();
return s;
}
func (P *Parser) ParseIfStat() *AST.Stat {
if P.verbose {
P.Trace("IfStat");
defer P.Ecart();
}
P.OpenScope();
s := P.ParseControlClause(Scanner.IF);
......@@ -1297,26 +1341,30 @@ func (P *Parser) ParseIfStat() *AST.Stat {
}
P.CloseScope();
P.Ecart();
return s;
}
func (P *Parser) ParseForStat() *AST.Stat {
if P.verbose {
P.Trace("ForStat");
defer P.Ecart();
}
P.OpenScope();
s := P.ParseControlClause(Scanner.FOR);
s.Body = P.ParseBlock(nil, Scanner.LBRACE);
P.CloseScope();
P.Ecart();
return s;
}
func (P *Parser) ParseSwitchCase() *AST.Stat {
if P.verbose {
P.Trace("SwitchCase");
defer P.Ecart();
}
s := AST.NewStat(P.pos, P.tok);
if P.tok == Scanner.CASE {
......@@ -1326,24 +1374,28 @@ func (P *Parser) ParseSwitchCase() *AST.Stat {
P.Expect(Scanner.DEFAULT);
}
P.Ecart();
return s;
}
func (P *Parser) ParseCaseClause() *AST.Stat {
if P.verbose {
P.Trace("CaseClause");
defer P.Ecart();
}
s := P.ParseSwitchCase();
s.Body = P.ParseBlock(nil, Scanner.COLON);
P.Ecart();
return s;
}
func (P *Parser) ParseSwitchStat() *AST.Stat {
if P.verbose {
P.Trace("SwitchStat");
defer P.Ecart();
}
P.OpenScope();
s := P.ParseControlClause(Scanner.SWITCH);
......@@ -1358,13 +1410,15 @@ func (P *Parser) ParseSwitchStat() *AST.Stat {
P.CloseScope();
s.Body = b;
P.Ecart();
return s;
}
func (P *Parser) ParseCommCase() *AST.Stat {
if P.verbose {
P.Trace("CommCase");
defer P.Ecart();
}
s := AST.NewStat(P.pos, P.tok);
if P.tok == Scanner.CASE {
......@@ -1375,7 +1429,7 @@ func (P *Parser) ParseCommCase() *AST.Stat {
P.Next();
if P.tok == Scanner.ARROW {
y := P.ParseExpression(1);
x = AST.NewExpr(pos, tok, x, y);
x = P.NewBinary(pos, tok, x, y);
} else {
P.Expect(Scanner.ARROW); // use Expect() error handling
}
......@@ -1385,24 +1439,28 @@ func (P *Parser) ParseCommCase() *AST.Stat {
P.Expect(Scanner.DEFAULT);
}
P.Ecart();
return s;
}
func (P *Parser) ParseCommClause() *AST.Stat {
if P.verbose {
P.Trace("CommClause");
defer P.Ecart();
}
s := P.ParseCommCase();
s.Body = P.ParseBlock(nil, Scanner.COLON);
P.Ecart();
return s;
}
func (P *Parser) ParseSelectStat() *AST.Stat {
if P.verbose {
P.Trace("SelectStat");
defer P.Ecart();
}
s := AST.NewStat(P.pos, Scanner.SELECT);
P.Expect(Scanner.SELECT);
......@@ -1416,13 +1474,15 @@ func (P *Parser) ParseSelectStat() *AST.Stat {
P.opt_semi = true;
s.Body = b;
P.Ecart();
return s;
}
func (P *Parser) ParseStatement() *AST.Stat {
if P.verbose {
P.Trace("Statement");
defer P.Ecart();
}
indent := P.indent;
s := AST.BadStat;
......@@ -1465,7 +1525,6 @@ func (P *Parser) ParseStatement() *AST.Stat {
if indent != P.indent {
panic("imbalanced tracing code (Statement)");
}
P.Ecart();
return s;
}
......@@ -1474,7 +1533,10 @@ func (P *Parser) ParseStatement() *AST.Stat {
// Declarations
func (P *Parser) ParseImportSpec(d *AST.Decl) {
if P.verbose {
P.Trace("ImportSpec");
defer P.Ecart();
}
if P.tok == Scanner.PERIOD {
P.Error(P.pos, `"import ." not yet handled properly`);
......@@ -1485,19 +1547,19 @@ func (P *Parser) ParseImportSpec(d *AST.Decl) {
if P.tok == Scanner.STRING {
// TODO eventually the scanner should strip the quotes
val := AST.NewObject(P.pos, AST.NONE, P.val);
d.Val = AST.NewLit(Scanner.STRING, val);
d.Val = &AST.BasicLit{P.pos, Scanner.STRING, P.val};
P.Next();
} else {
P.Expect(Scanner.STRING); // use Expect() error handling
}
P.Ecart();
}
func (P *Parser) ParseConstSpec(d *AST.Decl) {
if P.verbose {
P.Trace("ConstSpec");
defer P.Ecart();
}
d.Ident = P.ParseIdentList();
d.Typ = P.TryType();
......@@ -1505,24 +1567,26 @@ func (P *Parser) ParseConstSpec(d *AST.Decl) {
P.Next();
d.Val = P.ParseExpressionList();
}
P.Ecart();
}
func (P *Parser) ParseTypeSpec(d *AST.Decl) {
if P.verbose {
P.Trace("TypeSpec");
defer P.Ecart();
}
d.Ident = P.ParseIdent(nil);
d.Typ = P.ParseType();
P.opt_semi = true;
P.Ecart();
}
func (P *Parser) ParseVarSpec(d *AST.Decl) {
if P.verbose {
P.Trace("VarSpec");
defer P.Ecart();
}
d.Ident = P.ParseIdentList();
if P.tok == Scanner.ASSIGN {
......@@ -1535,8 +1599,6 @@ func (P *Parser) ParseVarSpec(d *AST.Decl) {
d.Val = P.ParseExpressionList();
}
}
P.Ecart();
}
......@@ -1560,17 +1622,17 @@ func (P *Parser) ParseSpec(d *AST.Decl) {
P.Declare(d.Ident, kind, d.Typ);
if d.Val != nil {
// initialization/assignment
llen := d.Ident.Len();
rlen := d.Val.Len();
llen := AST.ExprLen(d.Ident);
rlen := AST.ExprLen(d.Val);
if llen == rlen {
// TODO
} else if rlen == 1 {
// TODO
} else {
if llen < rlen {
P.Error(d.Val.At(llen).Pos, "more expressions than variables");
P.Error(AST.ExprAt(d.Val, llen).Pos(), "more expressions than variables");
} else {
P.Error(d.Ident.At(rlen).Pos, "more variables than expressions");
P.Error(AST.ExprAt(d.Ident, rlen).Pos(), "more variables than expressions");
}
}
} else {
......@@ -1581,7 +1643,10 @@ func (P *Parser) ParseSpec(d *AST.Decl) {
func (P *Parser) ParseDecl(keyword int) *AST.Decl {
if P.verbose {
P.Trace("Decl");
defer P.Ecart();
}
d := AST.NewDecl(P.pos, keyword);
P.Expect(keyword);
......@@ -1606,7 +1671,6 @@ func (P *Parser) ParseDecl(keyword int) *AST.Decl {
P.ParseSpec(d);
}
P.Ecart();
return d;
}
......@@ -1621,7 +1685,10 @@ func (P *Parser) ParseDecl(keyword int) *AST.Decl {
// func (recv) ident (params) (results)
func (P *Parser) ParseFunctionDecl() *AST.Decl {
if P.verbose {
P.Trace("FunctionDecl");
defer P.Ecart();
}
d := AST.NewDecl(P.pos, Scanner.FUNC);
P.Expect(Scanner.FUNC);
......@@ -1635,24 +1702,24 @@ func (P *Parser) ParseFunctionDecl() *AST.Decl {
}
}
d.Ident = P.ParseIdent(nil);
ident := P.ParseIdent(nil);
d.Ident = ident;
d.Typ = P.ParseSignature();
d.Typ.Key = recv;
if P.tok == Scanner.LBRACE {
f := AST.NewObject(d.Pos, AST.FUNC, d.Ident.Obj.Ident);
f.Typ = d.Typ;
f.Body = P.ParseBlock(d.Typ, Scanner.LBRACE);
d.Val = AST.NewLit(Scanner.FUNC, f);
d.Body = P.ParseBlock(d.Typ, Scanner.LBRACE);
}
P.Ecart();
return d;
}
func (P *Parser) ParseDeclaration() *AST.Decl {
if P.verbose {
P.Trace("Declaration");
defer P.Ecart();
}
indent := P.indent;
d := AST.BadDecl;
......@@ -1670,7 +1737,6 @@ func (P *Parser) ParseDeclaration() *AST.Decl {
if indent != P.indent {
panic("imbalanced tracing code (Declaration)");
}
P.Ecart();
return d;
}
......@@ -1679,7 +1745,10 @@ func (P *Parser) ParseDeclaration() *AST.Decl {
// Program
func (P *Parser) ParseProgram() *AST.Program {
if P.verbose {
P.Trace("Program");
defer P.Ecart();
}
P.OpenScope();
p := AST.NewProgram(P.pos);
......@@ -1705,6 +1774,5 @@ func (P *Parser) ParseProgram() *AST.Program {
p.Comments = P.comments;
P.CloseScope();
P.Ecart();
return p;
}
usr/gri/pretty/printer.go
View file @ c048ee21
......@@ -33,6 +33,26 @@ var (
)
// ----------------------------------------------------------------------------
// Elementary support
func unimplemented() {
panic("unimplemented");
}
func unreachable() {
panic("unreachable");
}
func assert(pred bool) {
if !pred {
panic("assertion failed");
}
}
// ----------------------------------------------------------------------------
// Printer
......@@ -76,6 +96,9 @@ type Printer struct {
// semantic state
state int; // current semantic state
laststate int; // state for last string
// expression precedence
prec int;
}
......@@ -104,6 +127,9 @@ func (P *Printer) Init(text io.Write, comments *array.Array) {
P.NextComment();
// formatting parameters & semantic state initialized correctly by default
// expression precedence
P.prec = Scanner.LowestPrec;
}
......@@ -384,24 +410,21 @@ func (P *Printer) HtmlEpilogue() {
}
func (P *Printer) HtmlIdentifier(x *AST.Expr) {
if x.Tok != Scanner.IDENT {
panic();
}
func (P *Printer) HtmlIdentifier(x *AST.Ident) {
obj := x.Obj;
if *html && obj.Kind != AST.NONE {
// depending on whether we have a declaration or use, generate different html
// - no need to htmlEscape ident
id := Utils.IntToString(obj.Id, 10);
if x.Pos == obj.Pos {
if x.Pos() == obj.Pos {
// probably the declaration of x
P.TaggedString(x.Pos, `<a name="id` + id + `">`, obj.Ident, `</a>`);
P.TaggedString(x.Pos(), `<a name="id` + id + `">`, obj.Ident, `</a>`);
} else {
// probably not the declaration of x
P.TaggedString(x.Pos, `<a href="#id` + id + `">`, obj.Ident, `</a>`);
P.TaggedString(x.Pos(), `<a href="#id` + id + `">`, obj.Ident, `</a>`);
}
} else {
P.String(x.Pos, obj.Ident);
P.String(x.Pos(), obj.Ident);
}
}
......@@ -409,32 +432,58 @@ func (P *Printer) HtmlIdentifier(x *AST.Expr) {
// ----------------------------------------------------------------------------
// Types
func (P *Printer) Type(t *AST.Type, full_function_type bool) int
func (P *Printer) Expr(x *AST.Expr)
func (P *Printer) Expr1(x *AST.Expr, prec1 int, full_function_type bool)
func (P *Printer) Type(t *AST.Type) int
func (P *Printer) Expr(x AST.Expr)
func (P *Printer) Parameters(pos int, list *array.Array) {
P.String(pos, "(");
if list != nil {
var prev int;
for i, n := 0, list.Len(); i < n; i++ {
x := list.At(i).(*AST.Expr);
x := list.At(i).(AST.Expr);
tok := Scanner.TYPE;
if dummy, is_ident := x.(*AST.Ident); is_ident {
tok = Scanner.IDENT;
}
if i > 0 {
if prev == x.Tok || prev == Scanner.TYPE {
if prev == tok || prev == Scanner.TYPE {
P.separator = comma;
} else {
P.separator = blank;
}
}
P.Expr(x);
prev = x.Tok;
prev = tok;
}
}
P.String(0, ")");
}
func (P *Printer) Fields(list *array.Array, end int, full_function_type bool) {
// Returns the separator (semicolon or none) required if
// the type is terminating a declaration or statement.
func (P *Printer) Signature(t *AST.Type) int {
assert(t.Form == AST.FUNCTION);
separator := none;
P.Parameters(t.Pos, t.List);
if t.Elt != nil {
P.separator = blank;
list := t.Elt.List;
dummy, is_type := list.At(0).(*AST.TypeLit);
if list.Len() > 1 || is_type && dummy.Typ.Form == AST.FUNCTION {
// single, anonymous result types which are functions must
// be parenthesized as well
P.Parameters(0, list);
} else {
// single, anonymous result type
separator = P.Type(list.At(0).(*AST.TypeLit).Typ);
}
}
return separator;
}
func (P *Printer) Fields(list *array.Array, end int, in_interface bool) {
P.state = opening_scope;
P.String(0, "{");
......@@ -442,19 +491,29 @@ func (P *Printer) Fields(list *array.Array, end int, full_function_type bool) {
P.newlines = 1;
var prev int;
for i, n := 0, list.Len(); i < n; i++ {
x := list.At(i).(*AST.Expr);
x := list.At(i).(AST.Expr);
tok := Scanner.TYPE;
if dummy, is_ident := x.(*AST.Ident); is_ident {
tok = Scanner.IDENT;
} else if dummy, is_lit := x.(*AST.BasicLit); is_lit && dummy.Tok == Scanner.STRING {
tok = Scanner.STRING;
}
if i > 0 {
if prev == Scanner.TYPE && x.Tok != Scanner.STRING || prev == Scanner.STRING {
if prev == Scanner.TYPE && tok != Scanner.STRING || prev == Scanner.STRING {
P.separator = semicolon;
P.newlines = 1;
} else if prev == x.Tok {
} else if prev == tok {
P.separator = comma;
} else {
P.separator = tab;
}
}
P.Expr1(x, Scanner.LowestPrec, full_function_type);
prev = x.Tok;
if in_interface && tok == Scanner.TYPE {
P.Signature(x.(*AST.TypeLit).Typ);
} else {
P.Expr(x);
}
prev = tok;
}
P.newlines = 1;
}
......@@ -466,7 +525,7 @@ func (P *Printer) Fields(list *array.Array, end int, full_function_type bool) {
// Returns the separator (semicolon or none) required if
// the type is terminating a declaration or statement.
func (P *Printer) Type(t *AST.Type, full_function_type bool) int {
func (P *Printer) Type(t *AST.Type) int {
separator := semicolon;
switch t.Form {
......@@ -479,7 +538,7 @@ func (P *Printer) Type(t *AST.Type, full_function_type bool) int {
P.Expr(t.Expr);
}
P.String(0, "]");
separator = P.Type(t.Elt, true);
separator = P.Type(t.Elt);
case AST.STRUCT, AST.INTERFACE:
switch t.Form {
......@@ -488,15 +547,15 @@ func (P *Printer) Type(t *AST.Type, full_function_type bool) int {
}
if t.List != nil {
P.separator = blank;
P.Fields(t.List, t.End, t.Form == AST.STRUCT);
P.Fields(t.List, t.End, t.Form == AST.INTERFACE);
}
separator = none;
case AST.MAP:
P.String(t.Pos, "map [");
P.Type(t.Key, true);
P.Type(t.Key);
P.String(0, "]");
separator = P.Type(t.Elt, true);
separator = P.Type(t.Elt);
case AST.CHANNEL:
var m string;
......@@ -506,29 +565,15 @@ func (P *Printer) Type(t *AST.Type, full_function_type bool) int {
case AST.SEND: m = "chan <- ";
}
P.String(t.Pos, m);
separator = P.Type(t.Elt, true);
separator = P.Type(t.Elt);
case AST.POINTER:
P.String(t.Pos, "*");
separator = P.Type(t.Elt, true);
separator = P.Type(t.Elt);
case AST.FUNCTION:
if full_function_type {
P.Token(0, Scanner.FUNC);
}
P.Parameters(t.Pos, t.List);
if t.Elt != nil {
P.separator = blank;
list := t.Elt.List;
if list.Len() > 1 || list.At(0).(*AST.Expr).Typ.Form == AST.FUNCTION {
// single, anonymous result types which are functions must
// be parenthesized as well
P.Parameters(0, list);
} else {
// single, anonymous result type
P.Expr(list.At(0).(*AST.Expr));
}
}
separator = P.Signature(t);
case AST.ELLIPSIS:
P.String(t.Pos, "...");
......@@ -545,105 +590,133 @@ func (P *Printer) Type(t *AST.Type, full_function_type bool) int {
// Expressions
func (P *Printer) Block(b *AST.Block, indent bool);
func (P *Printer) Expr1(x AST.Expr, prec1 int);
func (P *Printer) Expr1(x *AST.Expr, prec1 int, full_function_type bool) {
if x == nil {
return; // empty expression list
}
switch x.Tok {
case Scanner.TYPE:
// type expr
P.Type(x.Typ, full_function_type);
func (P *Printer) DoBadExpr(x *AST.BadExpr) {
P.String(0, "BadExpr");
}
case Scanner.IDENT:
func (P *Printer) DoIdent(x *AST.Ident) {
P.HtmlIdentifier(x);
}
case Scanner.INT, Scanner.STRING, Scanner.FLOAT:
// literal
P.String(x.Pos, x.Obj.Ident);
case Scanner.FUNC:
// function literal
P.String(x.Pos, "func");
P.Type(x.Obj.Typ, false);
P.Block(x.Obj.Body, true);
P.newlines = 0;
case Scanner.COMMA:
// list
func (P *Printer) DoBinaryExpr(x *AST.BinaryExpr) {
if x.Tok == Scanner.COMMA {
// (don't use binary expression printing because of different spacing)
P.Expr(x.X);
P.String(x.Pos, ",");
P.String(x.Pos(), ",");
P.separator = blank;
P.state = inside_list;
P.Expr(x.Y);
case Scanner.PERIOD:
// selector or type guard
P.Expr1(x.X, Scanner.HighestPrec, true);
P.String(x.Pos, ".");
if x.Y.Tok == Scanner.TYPE {
P.String(0, "(");
P.Expr(x.Y);
P.String(0, ")");
} else {
P.Expr1(x.Y, Scanner.HighestPrec, true);
prec := Scanner.Precedence(x.Tok);
if prec < P.prec {
P.String(0, "(");
}
case Scanner.LBRACK:
// index
P.Expr1(x.X, Scanner.HighestPrec, true);
P.String(x.Pos, "[");
P.Expr1(x.Y, 0, true);
P.String(0, "]");
case Scanner.LPAREN:
// call
P.Expr1(x.X, Scanner.HighestPrec, true);
P.String(x.Pos, "(");
P.Expr(x.Y);
P.Expr1(x.X, prec);
P.separator = blank;
P.Token(x.Pos(), x.Tok);
P.separator = blank;
P.Expr1(x.Y, prec);
if prec < P.prec {
P.String(0, ")");
}
}
}
case Scanner.LBRACE:
// composite literal
P.Type(x.Obj.Typ, true);
P.String(x.Pos, "{");
P.Expr(x.Y);
P.String(0, "}");
default:
// unary and binary expressions including ":" for pairs
func (P *Printer) DoUnaryExpr(x *AST.UnaryExpr) {
prec := Scanner.UnaryPrec;
if x.X != nil {
prec = Scanner.Precedence(x.Tok);
}
if prec < prec1 {
if prec < P.prec {
P.String(0, "(");
}
if x.X == nil {
// unary expression
P.Token(x.Pos, x.Tok);
P.Token(x.Pos(), x.Tok);
if x.Tok == Scanner.RANGE {
P.separator = blank;
}
} else {
// binary expression
P.Expr1(x.X, prec, true);
P.separator = blank;
P.Token(x.Pos, x.Tok);
P.separator = blank;
}
P.Expr1(x.Y, prec, true);
if prec < prec1 {
P.Expr1(x.X, prec);
if prec < P.prec {
P.String(0, ")");
}
}
func (P *Printer) DoBasicLit(x *AST.BasicLit) {
P.String(x.Pos(), x.Val);
}
func (P *Printer) DoTypeLit(x *AST.TypeLit) {
P.Type(x.Typ);
}
func (P *Printer) DoFunctionLit(x *AST.FunctionLit) {
P.String(x.Pos(), "func");
P.Signature(x.Typ);
P.separator = blank;
P.Block(x.Body, true);
P.newlines = 0;
}
func (P *Printer) DoCompositeLit(x *AST.CompositeLit) {
P.Type(x.Typ);
P.String(x.Pos(), "{");
P.Expr(x.Elts);
P.String(0, "}");
}
func (P *Printer) DoSelector(x *AST.Selector) {
P.Expr1(x.X, Scanner.HighestPrec);
P.String(x.Pos(), ".");
P.Expr1(x.Sel, Scanner.HighestPrec);
}
func (P *Printer) DoTypeGuard(x *AST.TypeGuard) {
P.Expr1(x.X, Scanner.HighestPrec);
P.String(x.Pos(), ".");
P.String(0, "(");
P.Type(x.Typ);
P.String(0, ")");
}
func (P *Printer) DoIndex(x *AST.Index) {
P.Expr1(x.X, Scanner.HighestPrec);
P.String(x.Pos(), "[");
P.Expr1(x.I, 0);
P.String(0, "]");
}
func (P *Printer) DoCall(x *AST.Call) {
P.Expr1(x.F, Scanner.HighestPrec);
P.String(x.Pos(), "(");
P.Expr(x.Args);
P.String(0, ")");
}
func (P *Printer) Expr1(x AST.Expr, prec1 int) {
if x == nil {
return; // empty expression list
}
saved_prec := P.prec;
P.prec = prec1;
x.Visit(P);
P.prec = saved_prec;
}
func (P *Printer) Expr(x *AST.Expr) {
P.Expr1(x, Scanner.LowestPrec, true);
func (P *Printer) Expr(x AST.Expr) {
P.Expr1(x, Scanner.LowestPrec);
}
......@@ -834,7 +907,7 @@ func (P *Printer) Declaration(d *AST.Decl, parenthesized bool) {
if d.Ident != nil {
P.Expr(d.Ident);
} else {
P.String(d.Val.Pos, ""); // flush pending ';' separator/newlines
P.String(d.Val.Pos(), ""); // flush pending ';' separator/newlines
}
P.separator = tab;
P.Expr(d.Val);
......@@ -843,13 +916,13 @@ func (P *Printer) Declaration(d *AST.Decl, parenthesized bool) {
case Scanner.TYPE:
P.Expr(d.Ident);
P.separator = blank; // TODO switch to tab? (but indentation problem with structs)
P.separator = P.Type(d.Typ, true);
P.separator = P.Type(d.Typ);
case Scanner.CONST, Scanner.VAR:
P.Expr(d.Ident);
if d.Typ != nil {
P.separator = blank; // TODO switch to tab? (indentation problem with structs)
P.separator = P.Type(d.Typ, true);
P.separator = P.Type(d.Typ);
}
if d.Val != nil {
P.separator = tab;
......@@ -866,10 +939,10 @@ func (P *Printer) Declaration(d *AST.Decl, parenthesized bool) {
P.separator = blank;
}
P.Expr(d.Ident);
P.separator = P.Type(d.Typ, false);
if d.Val != nil {
P.separator = P.Signature(d.Typ);
if d.Body != nil {
P.separator = blank;
P.Block(d.Val.Obj.Body, true);
P.Block(d.Body, true);
}
default:
......@@ -910,7 +983,7 @@ func Print(prog *AST.Program) {
P.Init(text, prog.Comments);
// TODO would be better to make the name of the src file be the title
P.HtmlPrologue("package " + prog.Ident.Obj.Ident);
P.HtmlPrologue("package " + prog.Ident.(*AST.Ident).Obj.Ident);
P.Program(prog);
P.HtmlEpilogue();
......
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