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|
/*-----------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All Rights Reserved.
//
//-----------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------
// Dafny
// Rustan Leino, first created 25 January 2008
//--------------------------------------------------------------------------*/
using System.Collections.Generic;
using System.Numerics;
using Microsoft.Boogie;
using System.IO;
using System.Text;
COMPILER Dafny
/*--------------------------------------------------------------------------*/
static List<ModuleDecl/*!*/> theModules;
static BuiltIns theBuiltIns;
static Expression/*!*/ dummyExpr = new LiteralExpr(Token.NoToken);
static FrameExpression/*!*/ dummyFrameExpr = new FrameExpression(dummyExpr, null);
static Statement/*!*/ dummyStmt = new ReturnStmt(Token.NoToken, null);
static Attributes.Argument/*!*/ dummyAttrArg = new Attributes.Argument(Token.NoToken, "dummyAttrArg");
static int anonymousIds = 0;
struct MemberModifiers {
public bool IsGhost;
public bool IsStatic;
public bool IsUnlimited;
}
// helper routine for parsing call statements
///<summary>
/// Parses top-level things (modules, classes, datatypes, class members) from "filename"
/// and appends them in appropriate form to "modules".
/// Returns the number of parsing errors encountered.
/// Note: first initialize the Scanner.
///</summary>
public static int Parse (string/*!*/ filename, List<ModuleDecl/*!*/>/*!*/ modules, BuiltIns builtIns) /* throws System.IO.IOException */ {
Contract.Requires(filename != null);
Contract.Requires(cce.NonNullElements(modules));
string s;
if (filename == "stdin.dfy") {
s = Microsoft.Boogie.ParserHelper.Fill(System.Console.In, new List<string>());
return Parse(s, filename, modules, builtIns);
} else {
using (System.IO.StreamReader reader = new System.IO.StreamReader(filename)) {
s = Microsoft.Boogie.ParserHelper.Fill(reader, new List<string>());
return Parse(s, filename, modules, builtIns);
}
}
}
///<summary>
/// Parses top-level things (modules, classes, datatypes, class members)
/// and appends them in appropriate form to "modules".
/// Returns the number of parsing errors encountered.
/// Note: first initialize the Scanner.
///</summary>
public static int Parse (string/*!*/ s, string/*!*/ filename, List<ModuleDecl/*!*/>/*!*/ modules, BuiltIns builtIns) {
Contract.Requires(s != null);
Contract.Requires(filename != null);
Contract.Requires(cce.NonNullElements(modules));
Errors errors = new Errors();
return Parse(s, filename, modules, builtIns, errors);
}
///<summary>
/// Parses top-level things (modules, classes, datatypes, class members)
/// and appends them in appropriate form to "modules".
/// Returns the number of parsing errors encountered.
/// Note: first initialize the Scanner with the given Errors sink.
///</summary>
public static int Parse (string/*!*/ s, string/*!*/ filename, List<ModuleDecl/*!*/>/*!*/ modules, BuiltIns builtIns,
Errors/*!*/ errors) {
Contract.Requires(s != null);
Contract.Requires(filename != null);
Contract.Requires(cce.NonNullElements(modules));
Contract.Requires(errors != null);
List<ModuleDecl/*!*/> oldModules = theModules;
theModules = modules;
BuiltIns oldBuiltIns = builtIns;
theBuiltIns = builtIns;
byte[]/*!*/ buffer = cce.NonNull( UTF8Encoding.Default.GetBytes(s));
MemoryStream ms = new MemoryStream(buffer,false);
Scanner scanner = new Scanner(ms, errors, filename);
Parser parser = new Parser(scanner, errors);
parser.Parse();
theModules = oldModules;
theBuiltIns = oldBuiltIns;
return parser.errors.count;
}
bool IsAttribute() {
Token x = scanner.Peek();
return la.kind == _lbrace && x.kind == _colon;
}
/*--------------------------------------------------------------------------*/
CHARACTERS
letter = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".
digit = "0123456789".
posDigit = "123456789".
special = "'_?\\".
glyph = "`~!@#$%^&*()-_=+[{]}|;:',<.>/?\\".
cr = '\r'.
lf = '\n'.
tab = '\t'.
space = ' '.
quote = '"'.
nondigit = letter + special.
idchar = nondigit + digit.
nonquote = letter + digit + space + glyph.
/* exclude the characters in 'array' */
nondigitMinusA = nondigit - 'a'.
idcharMinusA = idchar - 'a'.
idcharMinusR = idchar - 'r'.
idcharMinusY = idchar - 'y'.
idcharMinusPosDigit = idchar - posDigit.
/*------------------------------------------------------------------------*/
TOKENS
ident = nondigitMinusA {idchar} /* if char 0 is not an 'a', then anything else is fine */
| 'a' [ idcharMinusR {idchar} ] /* if char 0 is an 'a', then either there is no char 1 or char 1 is not an 'r' */
| 'a' 'r' [ idcharMinusR {idchar} ] /* etc. */
| 'a' 'r' 'r' [ idcharMinusA {idchar} ]
| 'a' 'r' 'r' 'a' [ idcharMinusY {idchar} ]
| 'a' 'r' 'r' 'a' 'y' idcharMinusPosDigit {idchar}
| 'a' 'r' 'r' 'a' 'y' posDigit {idchar} nondigit {idchar}.
digits = digit {digit}.
arrayToken = 'a' 'r' 'r' 'a' 'y' [posDigit {digit}].
string = quote {nonquote} quote.
colon = ':'.
lbrace = '{'.
rbrace = '}'.
COMMENTS FROM "/*" TO "*/" NESTED
COMMENTS FROM "//" TO lf
IGNORE cr + lf + tab
/*------------------------------------------------------------------------*/
PRODUCTIONS
Dafny
= (. ClassDecl/*!*/ c; DatatypeDecl/*!*/ dt; ArbitraryTypeDecl at;
Attributes attrs; IToken/*!*/ id; List<string/*!*/> theImports;
List<MemberDecl/*!*/> membersDefaultClass = new List<MemberDecl/*!*/>();
List<MemberDecl/*!*/> namedModuleDefaultClassMembers;
ModuleDecl module;
// to support multiple files, create a default module only if theModules doesn't already contain one
DefaultModuleDecl defaultModule = null;
foreach (ModuleDecl mdecl in theModules) {
defaultModule = mdecl as DefaultModuleDecl;
if (defaultModule != null) { break; }
}
bool defaultModuleCreatedHere = false;
if (defaultModule == null) {
defaultModuleCreatedHere = true;
defaultModule = new DefaultModuleDecl();
}
IToken idRefined;
bool isGhost;
.)
{ (. isGhost = false; .)
[ "ghost" (. isGhost = true; .) ]
( "module" (. attrs = null; idRefined = null; theImports = new List<string/*!*/>();
namedModuleDefaultClassMembers = new List<MemberDecl>();
.)
{ Attribute<ref attrs> }
Ident<out id> (. defaultModule.ImportNames.Add(id.val); .)
[ "refines" Ident<out idRefined> ]
[ "imports" Idents<theImports> ] (. module = new ModuleDecl(id, id.val, isGhost, idRefined == null ? null : idRefined.val, theImports, attrs); .)
"{" (. module.BodyStartTok = t; .)
{ ClassDecl<module, out c> (. module.TopLevelDecls.Add(c); .)
| DatatypeDecl<module, out dt> (. module.TopLevelDecls.Add(dt); .)
| ArbitraryTypeDecl<module, out at>(. module.TopLevelDecls.Add(at); .)
| ClassMemberDecl<namedModuleDefaultClassMembers, false, false>
}
"}" (. module.BodyEndTok = t;
module.TopLevelDecls.Add(new DefaultClassDecl(module, namedModuleDefaultClassMembers));
theModules.Add(module); .)
| (. if (isGhost) { SemErr(t, "a class is not allowed to be declared as 'ghost'"); } .)
ClassDecl<defaultModule, out c> (. defaultModule.TopLevelDecls.Add(c); .)
| (. if (isGhost) { SemErr(t, "a datatype/codatatype is not allowed to be declared as 'ghost'"); } .)
DatatypeDecl<defaultModule, out dt> (. defaultModule.TopLevelDecls.Add(dt); .)
| (. if (isGhost) { SemErr(t, "a type is not allowed to be declared as 'ghost'"); } .)
ArbitraryTypeDecl<defaultModule, out at> (. defaultModule.TopLevelDecls.Add(at); .)
| ClassMemberDecl<membersDefaultClass, isGhost, false>
)
}
(. if (defaultModuleCreatedHere) {
defaultModule.TopLevelDecls.Add(new DefaultClassDecl(defaultModule, membersDefaultClass));
theModules.Add(defaultModule);
} else {
// find the default class in the default module, then append membersDefaultClass to its member list
foreach (TopLevelDecl topleveldecl in defaultModule.TopLevelDecls) {
DefaultClassDecl defaultClass = topleveldecl as DefaultClassDecl;
if (defaultClass != null) {
defaultClass.Members.AddRange(membersDefaultClass);
break;
}
}
}
.)
EOF
.
ClassDecl<ModuleDecl/*!*/ module, out ClassDecl/*!*/ c>
= (. Contract.Requires(module != null);
Contract.Ensures(Contract.ValueAtReturn(out c) != null);
IToken/*!*/ id;
Attributes attrs = null;
List<TypeParameter/*!*/> typeArgs = new List<TypeParameter/*!*/>();
List<MemberDecl/*!*/> members = new List<MemberDecl/*!*/>();
IToken bodyStart;
.)
SYNC
"class"
{ Attribute<ref attrs> }
Ident<out id>
[ GenericParameters<typeArgs> ]
"{" (. bodyStart = t; .)
{ ClassMemberDecl<members, false, true>
}
"}"
(. c = new ClassDecl(id, id.val, module, typeArgs, members, attrs);
c.BodyStartTok = bodyStart;
c.BodyEndTok = t;
.)
.
ClassMemberDecl<.List<MemberDecl/*!*/>/*!*/ mm, bool isAlreadyGhost, bool allowConstructors.>
= (. Contract.Requires(cce.NonNullElements(mm));
Method/*!*/ m;
Function/*!*/ f;
MemberModifiers mmod = new MemberModifiers();
mmod.IsGhost = isAlreadyGhost;
.)
{ "ghost" (. mmod.IsGhost = true; .)
| "static" (. mmod.IsStatic = true; .)
| "unlimited" (. mmod.IsUnlimited = true; .)
}
( FieldDecl<mmod, mm>
| FunctionDecl<mmod, out f> (. mm.Add(f); .)
| MethodDecl<mmod, allowConstructors, out m> (. mm.Add(m); .)
)
.
DatatypeDecl<ModuleDecl/*!*/ module, out DatatypeDecl/*!*/ dt>
= (. Contract.Requires(module != null);
Contract.Ensures(Contract.ValueAtReturn(out dt)!=null);
IToken/*!*/ id;
Attributes attrs = null;
List<TypeParameter/*!*/> typeArgs = new List<TypeParameter/*!*/>();
List<DatatypeCtor/*!*/> ctors = new List<DatatypeCtor/*!*/>();
IToken bodyStart = Token.NoToken; // dummy assignment
bool co = false;
.)
SYNC
( "datatype"
| "codatatype" (. co = true; .)
)
{ Attribute<ref attrs> }
Ident<out id>
[ GenericParameters<typeArgs> ]
"=" (. bodyStart = t; .)
DatatypeMemberDecl<ctors>
{ "|" DatatypeMemberDecl<ctors> }
SYNC ";"
(. if (co) {
dt = new CoDatatypeDecl(id, id.val, module, typeArgs, ctors, attrs);
} else {
dt = new IndDatatypeDecl(id, id.val, module, typeArgs, ctors, attrs);
}
dt.BodyStartTok = bodyStart;
dt.BodyEndTok = t;
.)
.
DatatypeMemberDecl<.List<DatatypeCtor/*!*/>/*!*/ ctors.>
= (. Contract.Requires(cce.NonNullElements(ctors));
Attributes attrs = null;
IToken/*!*/ id;
List<Formal/*!*/> formals = new List<Formal/*!*/>();
.)
{ Attribute<ref attrs> }
Ident<out id>
[ FormalsOptionalIds<formals> ]
(. ctors.Add(new DatatypeCtor(id, id.val, formals, attrs)); .)
.
FieldDecl<.MemberModifiers mmod, List<MemberDecl/*!*/>/*!*/ mm.>
= (. Contract.Requires(cce.NonNullElements(mm));
Attributes attrs = null;
IToken/*!*/ id; Type/*!*/ ty;
.)
SYNC
"var"
(. if (mmod.IsUnlimited) { SemErr(t, "fields cannot be declared 'unlimited'"); }
if (mmod.IsStatic) { SemErr(t, "fields cannot be declared 'static'"); }
.)
{ Attribute<ref attrs> }
IdentType<out id, out ty> (. mm.Add(new Field(id, id.val, mmod.IsGhost, ty, attrs)); .)
{ "," IdentType<out id, out ty> (. mm.Add(new Field(id, id.val, mmod.IsGhost, ty, attrs)); .)
}
SYNC ";"
.
ArbitraryTypeDecl<ModuleDecl/*!*/ module, out ArbitraryTypeDecl at>
= (. IToken/*!*/ id;
Attributes attrs = null;
.)
"type"
{ Attribute<ref attrs> }
Ident<out id> (. at = new ArbitraryTypeDecl(id, id.val, module, attrs); .)
SYNC ";"
.
GIdentType<bool allowGhostKeyword, out IToken/*!*/ id, out Type/*!*/ ty, out bool isGhost>
/* isGhost always returns as false if allowGhostKeyword is false */
= (. Contract.Ensures(Contract.ValueAtReturn(out id)!=null);
Contract.Ensures(Contract.ValueAtReturn(out ty)!=null);
isGhost = false; .)
[ "ghost" (. if (allowGhostKeyword) { isGhost = true; } else { SemErr(t, "formal cannot be declared 'ghost' in this context"); } .)
]
IdentType<out id, out ty>
.
IdentType<out IToken/*!*/ id, out Type/*!*/ ty>
= (.Contract.Ensures(Contract.ValueAtReturn(out id) != null); Contract.Ensures(Contract.ValueAtReturn(out ty) != null);.)
Ident<out id>
":"
Type<out ty>
.
LocalIdentTypeOptional<out VarDecl/*!*/ var, bool isGhost>
= (. IToken/*!*/ id; Type/*!*/ ty; Type optType = null;
.)
Ident<out id>
[ ":" Type<out ty> (. optType = ty; .)
]
(. var = new VarDecl(id, id.val, optType == null ? new InferredTypeProxy() : optType, isGhost); .)
.
IdentTypeOptional<out BoundVar/*!*/ var>
= (. Contract.Ensures(Contract.ValueAtReturn(out var)!=null); IToken/*!*/ id; Type/*!*/ ty; Type optType = null;
.)
Ident<out id>
[ ":" Type<out ty> (. optType = ty; .)
]
(. var = new BoundVar(id, id.val, optType == null ? new InferredTypeProxy() : optType); .)
.
TypeIdentOptional<out IToken/*!*/ id, out string/*!*/ identName, out Type/*!*/ ty, out bool isGhost>
= (.Contract.Ensures(Contract.ValueAtReturn(out id)!=null);
Contract.Ensures(Contract.ValueAtReturn(out ty)!=null);
Contract.Ensures(Contract.ValueAtReturn(out identName)!=null);
string name = null; isGhost = false; .)
[ "ghost" (. isGhost = true; .)
]
TypeAndToken<out id, out ty>
[ ":"
(. /* try to convert ty to an identifier */
UserDefinedType udt = ty as UserDefinedType;
if (udt != null && udt.TypeArgs.Count == 0) {
name = udt.Name;
} else {
SemErr(id, "invalid formal-parameter name in datatype constructor");
}
.)
Type<out ty>
]
(. if (name != null) {
identName = name;
} else {
identName = "#" + anonymousIds++;
}
.)
.
/*------------------------------------------------------------------------*/
GenericParameters<.List<TypeParameter/*!*/>/*!*/ typeArgs.>
= (. Contract.Requires(cce.NonNullElements(typeArgs));
IToken/*!*/ id; .)
"<"
Ident<out id> (. typeArgs.Add(new TypeParameter(id, id.val)); .)
{ "," Ident<out id> (. typeArgs.Add(new TypeParameter(id, id.val)); .)
}
">"
.
/*------------------------------------------------------------------------*/
MethodDecl<MemberModifiers mmod, bool allowConstructor, out Method/*!*/ m>
= (. Contract.Ensures(Contract.ValueAtReturn(out m) !=null);
IToken/*!*/ id;
Attributes attrs = null;
List<TypeParameter/*!*/>/*!*/ typeArgs = new List<TypeParameter/*!*/>();
IToken openParen;
List<Formal/*!*/> ins = new List<Formal/*!*/>();
List<Formal/*!*/> outs = new List<Formal/*!*/>();
List<MaybeFreeExpression/*!*/> req = new List<MaybeFreeExpression/*!*/>();
List<FrameExpression/*!*/> mod = new List<FrameExpression/*!*/>();
List<MaybeFreeExpression/*!*/> ens = new List<MaybeFreeExpression/*!*/>();
List<Expression/*!*/> dec = new List<Expression/*!*/>();
Attributes decAttrs = null;
Attributes modAttrs = null;
BlockStmt body = null;
bool isConstructor = false;
bool signatureOmitted = false;
IToken bodyStart = Token.NoToken;
IToken bodyEnd = Token.NoToken;
.)
SYNC
( "method"
| "constructor" (. if (allowConstructor) {
isConstructor = true;
} else {
SemErr(t, "constructors are only allowed in classes");
}
.)
)
(. if (mmod.IsUnlimited) { SemErr(t, "methods cannot be declared 'unlimited'"); }
if (isConstructor) {
if (mmod.IsGhost) {
SemErr(t, "constructors cannot be declared 'ghost'");
}
if (mmod.IsStatic) {
SemErr(t, "constructors cannot be declared 'static'");
}
}
.)
{ Attribute<ref attrs> }
Ident<out id>
(
[ GenericParameters<typeArgs> ]
Formals<true, !mmod.IsGhost, ins, out openParen>
[ "returns" (. if (isConstructor) { SemErr(t, "constructors cannot have out-parameters"); } .)
Formals<false, !mmod.IsGhost, outs, out openParen>
]
| "..." (. signatureOmitted = true; openParen = Token.NoToken; .)
)
{ MethodSpec<req, mod, ens, dec, ref decAttrs, ref modAttrs> }
[ BlockStmt<out body, out bodyStart, out bodyEnd>
]
(. if (isConstructor) {
m = new Constructor(id, id.val, typeArgs, ins,
req, new Specification<FrameExpression>(mod, modAttrs), ens, new Specification<Expression>(dec, decAttrs), body, attrs, signatureOmitted);
} else {
m = new Method(id, id.val, mmod.IsStatic, mmod.IsGhost, typeArgs, ins, outs,
req, new Specification<FrameExpression>(mod, modAttrs), ens, new Specification<Expression>(dec, decAttrs), body, attrs, signatureOmitted);
}
m.BodyStartTok = bodyStart;
m.BodyEndTok = bodyEnd;
.)
.
MethodSpec<.List<MaybeFreeExpression/*!*/>/*!*/ req, List<FrameExpression/*!*/>/*!*/ mod, List<MaybeFreeExpression/*!*/>/*!*/ ens,
List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes modAttrs.>
= (. Contract.Requires(cce.NonNullElements(req)); Contract.Requires(cce.NonNullElements(mod)); Contract.Requires(cce.NonNullElements(ens)); Contract.Requires(cce.NonNullElements(decreases));
Expression/*!*/ e; FrameExpression/*!*/ fe; bool isFree = false; Attributes ensAttrs = null;
.)
SYNC
( "modifies" { IF(IsAttribute()) Attribute<ref modAttrs> }
[ FrameExpression<out fe> (. mod.Add(fe); .)
{ "," FrameExpression<out fe> (. mod.Add(fe); .)
}
] SYNC ";"
| [ "free" (. isFree = true; .)
]
( "requires" Expression<out e> SYNC ";" (. req.Add(new MaybeFreeExpression(e, isFree)); .)
| "ensures" { IF(IsAttribute()) Attribute<ref ensAttrs> } Expression<out e> SYNC ";" (. ens.Add(new MaybeFreeExpression(e, isFree, ensAttrs)); .)
)
| "decreases" { IF(IsAttribute()) Attribute<ref decAttrs> } DecreasesList<decreases, false> SYNC ";"
)
.
Formals<.bool incoming, bool allowGhostKeyword, List<Formal/*!*/>/*!*/ formals, out IToken openParen.>
= (. Contract.Requires(cce.NonNullElements(formals)); IToken/*!*/ id; Type/*!*/ ty; bool isGhost; .)
"(" (. openParen = t; .)
[
GIdentType<allowGhostKeyword, out id, out ty, out isGhost> (. formals.Add(new Formal(id, id.val, ty, incoming, isGhost)); .)
{ "," GIdentType<allowGhostKeyword, out id, out ty, out isGhost> (. formals.Add(new Formal(id, id.val, ty, incoming, isGhost)); .)
}
]
")"
.
FormalsOptionalIds<.List<Formal/*!*/>/*!*/ formals.>
= (. Contract.Requires(cce.NonNullElements(formals)); IToken/*!*/ id; Type/*!*/ ty; string/*!*/ name; bool isGhost; .)
"("
[
TypeIdentOptional<out id, out name, out ty, out isGhost> (. formals.Add(new Formal(id, name, ty, true, isGhost)); .)
{ "," TypeIdentOptional<out id, out name, out ty, out isGhost> (. formals.Add(new Formal(id, name, ty, true, isGhost)); .)
}
]
")"
.
/*------------------------------------------------------------------------*/
Type<out Type/*!*/ ty>
= (. Contract.Ensures(Contract.ValueAtReturn(out ty) != null); IToken/*!*/ tok; .)
TypeAndToken<out tok, out ty>
.
TypeAndToken<out IToken/*!*/ tok, out Type/*!*/ ty>
= (. Contract.Ensures(Contract.ValueAtReturn(out tok)!=null); Contract.Ensures(Contract.ValueAtReturn(out ty) != null); tok = Token.NoToken; ty = new BoolType(); /*keep compiler happy*/
List<Type/*!*/>/*!*/ gt;
.)
( "bool" (. tok = t; .)
| "nat" (. tok = t; ty = new NatType(); .)
| "int" (. tok = t; ty = new IntType(); .)
| "set" (. tok = t; gt = new List<Type/*!*/>(); .)
GenericInstantiation<gt> (. if (gt.Count != 1) {
SemErr("set type expects exactly one type argument");
}
ty = new SetType(gt[0]);
.)
| "multiset" (. tok = t; gt = new List<Type/*!*/>(); .)
GenericInstantiation<gt> (. if (gt.Count != 1) {
SemErr("multiset type expects exactly one type argument");
}
ty = new MultiSetType(gt[0]);
.)
| "seq" (. tok = t; gt = new List<Type/*!*/>(); .)
GenericInstantiation<gt> (. if (gt.Count != 1) {
SemErr("seq type expects exactly one type argument");
}
ty = new SeqType(gt[0]);
.)
| "map" (. tok = t; gt = new List<Type/*!*/>(); .)
GenericInstantiation<gt> (. if (gt.Count != 2) {
SemErr("map type expects exactly two type arguments");
}
ty = new MapType(gt[0], gt[1]);
.)
| ReferenceType<out tok, out ty>
)
.
ReferenceType<out IToken/*!*/ tok, out Type/*!*/ ty>
= (. Contract.Ensures(Contract.ValueAtReturn(out tok) != null); Contract.Ensures(Contract.ValueAtReturn(out ty) != null);
tok = Token.NoToken; ty = new BoolType(); /*keep compiler happy*/
List<Type/*!*/>/*!*/ gt;
.)
( "object" (. tok = t; ty = new ObjectType(); .)
| arrayToken (. tok = t; gt = new List<Type/*!*/>(); .)
GenericInstantiation<gt> (. if (gt.Count != 1) {
SemErr("array type expects exactly one type argument");
}
int dims = 1;
if (tok.val.Length != 5) {
dims = int.Parse(tok.val.Substring(5));
}
ty = theBuiltIns.ArrayType(tok, dims, gt[0], true);
.)
| Ident<out tok> (. gt = new List<Type/*!*/>(); .)
[ GenericInstantiation<gt> ] (. ty = new UserDefinedType(tok, tok.val, gt); .)
)
.
GenericInstantiation<.List<Type/*!*/>/*!*/ gt.>
= (. Contract.Requires(cce.NonNullElements(gt)); Type/*!*/ ty; .)
"<"
Type<out ty> (. gt.Add(ty); .)
{ "," Type<out ty> (. gt.Add(ty); .)
}
">"
.
/*------------------------------------------------------------------------*/
FunctionDecl<MemberModifiers mmod, out Function/*!*/ f>
= (. Contract.Ensures(Contract.ValueAtReturn(out f)!=null);
Attributes attrs = null;
IToken/*!*/ id = Token.NoToken; // to please compiler
List<TypeParameter/*!*/> typeArgs = new List<TypeParameter/*!*/>();
List<Formal/*!*/> formals = new List<Formal/*!*/>();
Type/*!*/ returnType = new BoolType();
List<Expression/*!*/> reqs = new List<Expression/*!*/>();
List<Expression/*!*/> ens = new List<Expression/*!*/>();
List<FrameExpression/*!*/> reads = new List<FrameExpression/*!*/>();
List<Expression/*!*/> decreases = new List<Expression/*!*/>();
Expression body = null;
bool isPredicate = false;
bool isFunctionMethod = false;
IToken openParen = null;
IToken bodyStart = Token.NoToken;
IToken bodyEnd = Token.NoToken;
bool signatureOmitted = false;
.)
/* ----- function ----- */
( "function"
[ "method" (. isFunctionMethod = true; .)
]
(. if (mmod.IsGhost) { SemErr(t, "functions cannot be declared 'ghost' (they are ghost by default)"); }
.)
{ Attribute<ref attrs> }
Ident<out id>
(
[ GenericParameters<typeArgs> ]
Formals<true, isFunctionMethod, formals, out openParen>
":"
Type<out returnType>
| "..." (. signatureOmitted = true;
openParen = Token.NoToken; .)
)
/* ----- predicate ----- */
| "predicate" (. isPredicate = true; .)
[ "method" (. isFunctionMethod = true; .)
]
(. if (mmod.IsGhost) { SemErr(t, "predicates cannot be declared 'ghost' (they are ghost by default)"); }
.)
{ Attribute<ref attrs> }
Ident<out id>
(
[ GenericParameters<typeArgs> ]
[ Formals<true, isFunctionMethod, formals, out openParen>
[ ":" (. SemErr(t, "predicates do not have an explicitly declared return type; it is always bool"); .)
]
]
| "..." (. signatureOmitted = true;
openParen = Token.NoToken; .)
)
)
{ FunctionSpec<reqs, reads, ens, decreases> }
[ FunctionBody<out body, out bodyStart, out bodyEnd>
]
(. if (isPredicate) {
f = new Predicate(id, id.val, mmod.IsStatic, !isFunctionMethod, mmod.IsUnlimited, typeArgs, openParen, formals,
reqs, reads, ens, new Specification<Expression>(decreases, null), body, false, attrs, signatureOmitted);
} else {
f = new Function(id, id.val, mmod.IsStatic, !isFunctionMethod, mmod.IsUnlimited, typeArgs, openParen, formals, returnType,
reqs, reads, ens, new Specification<Expression>(decreases, null), body, attrs, signatureOmitted);
}
f.BodyStartTok = bodyStart;
f.BodyEndTok = bodyEnd;
.)
.
FunctionSpec<.List<Expression/*!*/>/*!*/ reqs, List<FrameExpression/*!*/>/*!*/ reads, List<Expression/*!*/>/*!*/ ens, List<Expression/*!*/>/*!*/ decreases.>
= (. Contract.Requires(cce.NonNullElements(reqs)); Contract.Requires(cce.NonNullElements(reads)); Contract.Requires(cce.NonNullElements(decreases));
Expression/*!*/ e; FrameExpression/*!*/ fe; .)
(
SYNC
"requires" Expression<out e> SYNC ";" (. reqs.Add(e); .)
| "reads" [ PossiblyWildFrameExpression<out fe> (. reads.Add(fe); .)
{ "," PossiblyWildFrameExpression<out fe> (. reads.Add(fe); .)
}
] SYNC ";"
| "ensures" Expression<out e> SYNC ";" (. ens.Add(e); .)
| "decreases" DecreasesList<decreases, false> SYNC ";"
)
.
PossiblyWildExpression<out Expression/*!*/ e>
= (. Contract.Ensures(Contract.ValueAtReturn(out e)!=null);
e = dummyExpr; .)
/* A decreases clause on a loop asks that no termination check be performed.
* Use of this feature is sound only with respect to partial correctness.
*/
( "*" (. e = new WildcardExpr(t); .)
| Expression<out e>
)
.
PossiblyWildFrameExpression<out FrameExpression/*!*/ fe>
= (. Contract.Ensures(Contract.ValueAtReturn(out fe) != null); fe = dummyFrameExpr; .)
/* A reads clause can list a wildcard, which allows the enclosing function to
* read anything. In many cases, and in particular in all cases where
* the function is defined recursively, this makes it next to impossible to make
* any use of the function. Nevertheless, as an experimental feature, the
* language allows it (and it is sound).
*/
( "*" (. fe = new FrameExpression(new WildcardExpr(t), null); .)
| FrameExpression<out fe>
)
.
FrameExpression<out FrameExpression/*!*/ fe>
= (. Contract.Ensures(Contract.ValueAtReturn(out fe) != null); Expression/*!*/ e; IToken/*!*/ id; string fieldName = null; .)
Expression<out e>
[ "`" Ident<out id> (. fieldName = id.val; .)
]
(. fe = new FrameExpression(e, fieldName); .)
.
FunctionBody<out Expression/*!*/ e, out IToken bodyStart, out IToken bodyEnd>
= (. Contract.Ensures(Contract.ValueAtReturn(out e) != null); e = dummyExpr; .)
"{" (. bodyStart = t; .)
Expression<out e>
"}" (. bodyEnd = t; .)
.
/*------------------------------------------------------------------------*/
BlockStmt<out BlockStmt/*!*/ block, out IToken bodyStart, out IToken bodyEnd>
= (. Contract.Ensures(Contract.ValueAtReturn(out block) != null);
List<Statement/*!*/> body = new List<Statement/*!*/>();
.)
"{" (. bodyStart = t; .)
{ Stmt<body>
}
"}" (. bodyEnd = t;
block = new BlockStmt(bodyStart, body); .)
.
Stmt<.List<Statement/*!*/>/*!*/ ss.>
= (. Statement/*!*/ s;
.)
OneStmt<out s> (. ss.Add(s); .)
.
OneStmt<out Statement/*!*/ s>
= (. Contract.Ensures(Contract.ValueAtReturn(out s) != null); IToken/*!*/ x; IToken/*!*/ id; string label = null;
s = dummyStmt; /* to please the compiler */
BlockStmt bs;
IToken bodyStart, bodyEnd;
int breakCount;
.)
SYNC
( BlockStmt<out bs, out bodyStart, out bodyEnd> (. s = bs; .)
| AssertStmt<out s>
| AssumeStmt<out s>
| PrintStmt<out s>
| UpdateStmt<out s>
| VarDeclStatement<out s>
| IfStmt<out s>
| WhileStmt<out s>
| MatchStmt<out s>
| ParallelStmt<out s>
| "label" (. x = t; .)
Ident<out id> ":"
OneStmt<out s> (. s.Labels = new LabelNode(x, id.val, s.Labels); .)
| "break" (. x = t; breakCount = 1; label = null; .)
( Ident<out id> (. label = id.val; .)
| { "break" (. breakCount++; .)
}
)
SYNC
";" (. s = label != null ? new BreakStmt(x, label) : new BreakStmt(x, breakCount); .)
| ReturnStmt<out s>
| "..." (. s = new SkeletonStatement(t); .)
";"
)
.
ReturnStmt<out Statement/*!*/ s>
= (.
IToken returnTok = null;
List<AssignmentRhs> rhss = null;
AssignmentRhs r;
.)
"return" (. returnTok = t; .)
[
Rhs<out r, null> (. rhss = new List<AssignmentRhs>(); rhss.Add(r); .)
{ "," Rhs<out r, null> (. rhss.Add(r); .)
}
]
";" (. s = new ReturnStmt(returnTok, rhss); .)
.
UpdateStmt<out Statement/*!*/ s>
= (. List<Expression> lhss = new List<Expression>();
List<AssignmentRhs> rhss = new List<AssignmentRhs>();
Expression e; AssignmentRhs r;
Expression lhs0;
IToken x;
Attributes attrs = null;
Expression suchThat = null;
.)
Lhs<out e> (. x = e.tok; .)
( { Attribute<ref attrs> }
";" (. rhss.Add(new ExprRhs(e, attrs)); .)
| (. lhss.Add(e); lhs0 = e; .)
{ "," Lhs<out e> (. lhss.Add(e); .)
}
( ":=" (. x = t; .)
Rhs<out r, lhs0> (. rhss.Add(r); .)
{ "," Rhs<out r, lhs0> (. rhss.Add(r); .)
}
| ":|" (. x = t; .)
Expression<out suchThat>
)
";"
| ":" (. SemErr(t, "invalid statement (did you forget the 'label' keyword?)"); .)
)
(. if (suchThat != null) {
s = new AssignSuchThatStmt(x, lhss, suchThat);
} else {
s = new UpdateStmt(x, lhss, rhss);
}
.)
.
Rhs<out AssignmentRhs r, Expression receiverForInitCall>
= (. IToken/*!*/ x, newToken; Expression/*!*/ e;
List<Expression> ee = null;
Type ty = null;
CallStmt initCall = null;
List<Expression> args;
r = null; // to please compiler
Attributes attrs = null;
.)
( "new" (. newToken = t; .)
TypeAndToken<out x, out ty>
[ "[" (. ee = new List<Expression>(); .)
Expressions<ee>
"]" (. // make sure an array class with this dimensionality exists
UserDefinedType tmp = theBuiltIns.ArrayType(x, ee.Count, new IntType(), true);
.)
| "." Ident<out x>
"(" (. args = new List<Expression/*!*/>(); .)
[ Expressions<args> ]
")" (. initCall = new CallStmt(x, new List<Expression>(),
receiverForInitCall, x.val, args); .)
]
(. if (ee != null) {
r = new TypeRhs(newToken, ty, ee);
} else {
r = new TypeRhs(newToken, ty, initCall);
}
.)
/* One day, the choose expression should be treated just as a special case of a method call. */
| "choose" (. x = t; .)
Expression<out e> (. r = new ExprRhs(new UnaryExpr(x, UnaryExpr.Opcode.SetChoose, e)); .)
| "*" (. r = new HavocRhs(t); .)
| Expression<out e> (. r = new ExprRhs(e); .)
)
{ Attribute<ref attrs> } (. r.Attributes = attrs; .)
.
VarDeclStatement<.out Statement/*!*/ s.>
= (. IToken x = null, assignTok = null; bool isGhost = false;
VarDecl/*!*/ d;
AssignmentRhs r; IdentifierExpr lhs0;
List<VarDecl> lhss = new List<VarDecl>();
List<AssignmentRhs> rhss = new List<AssignmentRhs>();
Expression suchThat = null;
.)
[ "ghost" (. isGhost = true; x = t; .)
]
"var" (. if (!isGhost) { x = t; } .)
LocalIdentTypeOptional<out d, isGhost> (. lhss.Add(d); .)
{ ","
LocalIdentTypeOptional<out d, isGhost> (. lhss.Add(d); .)
}
[ ":=" (. assignTok = t;
lhs0 = new IdentifierExpr(lhss[0].Tok, lhss[0].Name);
lhs0.Var = lhss[0]; lhs0.Type = lhss[0].OptionalType; // resolve here
.)
Rhs<out r, lhs0> (. rhss.Add(r); .)
{ "," Rhs<out r, lhs0> (. rhss.Add(r); .)
}
| ":|" (. assignTok = t; .)
Expression<out suchThat>
]
";"
(. ConcreteUpdateStatement update;
if (suchThat != null) {
var ies = new List<Expression>();
foreach (var lhs in lhss) {
ies.Add(new IdentifierExpr(lhs.Tok, lhs.Name));
}
update = new AssignSuchThatStmt(assignTok, ies, suchThat);
} else if (rhss.Count == 0) {
update = null;
} else {
var ies = new List<Expression>();
foreach (var lhs in lhss) {
ies.Add(new AutoGhostIdentifierExpr(lhs.Tok, lhs.Name));
}
update = new UpdateStmt(assignTok, ies, rhss);
}
s = new VarDeclStmt(x, lhss, update);
.)
.
IfStmt<out Statement/*!*/ ifStmt>
= (. Contract.Ensures(Contract.ValueAtReturn(out ifStmt) != null); IToken/*!*/ x;
Expression guard = null; bool guardOmitted = false;
BlockStmt/*!*/ thn;
BlockStmt/*!*/ bs;
Statement/*!*/ s;
Statement els = null;
IToken bodyStart, bodyEnd;
List<GuardedAlternative> alternatives;
ifStmt = dummyStmt; // to please the compiler
.)
"if" (. x = t; .)
(
( Guard<out guard>
| "..." (. guardOmitted = true; .)
)
BlockStmt<out thn, out bodyStart, out bodyEnd>
[ "else"
( IfStmt<out s> (. els = s; .)
| BlockStmt<out bs, out bodyStart, out bodyEnd> (. els = bs; .)
)
]
(. if (guardOmitted) {
ifStmt = new SkeletonStatement(new IfStmt(x, guard, thn, els), true, false);
} else {
ifStmt = new IfStmt(x, guard, thn, els);
}
.)
|
AlternativeBlock<out alternatives>
(. ifStmt = new AlternativeStmt(x, alternatives); .)
)
.
AlternativeBlock<.out List<GuardedAlternative> alternatives.>
= (. alternatives = new List<GuardedAlternative>();
IToken x;
Expression e;
List<Statement> body;
.)
"{"
{ "case" (. x = t; .)
Expression<out e>
"=>"
(. body = new List<Statement>(); .)
{ Stmt<body> }
(. alternatives.Add(new GuardedAlternative(x, e, body)); .)
}
"}"
.
WhileStmt<out Statement/*!*/ stmt>
= (. Contract.Ensures(Contract.ValueAtReturn(out stmt) != null); IToken/*!*/ x;
Expression guard = null; bool guardOmitted = false;
List<MaybeFreeExpression/*!*/> invariants = new List<MaybeFreeExpression/*!*/>();
List<Expression/*!*/> decreases = new List<Expression/*!*/>();
Attributes decAttrs = null;
Attributes modAttrs = null;
List<FrameExpression/*!*/> mod = null;
BlockStmt/*!*/ body = null; bool bodyOmitted = false;
IToken bodyStart = null, bodyEnd = null;
List<GuardedAlternative> alternatives;
stmt = dummyStmt; // to please the compiler
.)
"while" (. x = t; .)
(
( Guard<out guard> (. Contract.Assume(guard == null || cce.Owner.None(guard)); .)
| "..." (. guardOmitted = true; .)
)
LoopSpec<out invariants, out decreases, out mod, ref decAttrs, ref modAttrs>
( BlockStmt<out body, out bodyStart, out bodyEnd>
| "..." (. bodyOmitted = true; .)
)
(.
if (guardOmitted || bodyOmitted) {
if (decreases.Count != 0) {
SemErr(decreases[0].tok, "'decreases' clauses are not allowed on refining loops");
}
if (mod != null) {
SemErr(mod[0].E.tok, "'modifies' clauses are not allowed on refining loops");
}
if (body == null) {
body = new BlockStmt(x, new List<Statement>());
}
stmt = new WhileStmt(x, guard, invariants, new Specification<Expression>(null, null), new Specification<FrameExpression>(null, null), body);
stmt = new SkeletonStatement(stmt, guardOmitted, bodyOmitted);
} else {
stmt = new WhileStmt(x, guard, invariants, new Specification<Expression>(decreases, decAttrs), new Specification<FrameExpression>(mod, modAttrs), body);
}
.)
|
LoopSpec<out invariants, out decreases, out mod, ref decAttrs, ref modAttrs>
AlternativeBlock<out alternatives>
(. stmt = new AlternativeLoopStmt(x, invariants, new Specification<Expression>(decreases, decAttrs), new Specification<FrameExpression>(mod, modAttrs), alternatives); .)
)
.
LoopSpec<.out List<MaybeFreeExpression/*!*/> invariants, out List<Expression/*!*/> decreases, out List<FrameExpression/*!*/> mod, ref Attributes decAttrs, ref Attributes modAttrs.>
= (. FrameExpression/*!*/ fe;
invariants = new List<MaybeFreeExpression/*!*/>();
MaybeFreeExpression invariant = null;
decreases = new List<Expression/*!*/>();
mod = null;
.)
{
Invariant<out invariant> SYNC ";" (. invariants.Add(invariant); .)
| SYNC "decreases"
{ IF(IsAttribute()) Attribute<ref decAttrs> }
DecreasesList<decreases, true> SYNC ";"
| SYNC "modifies"
{ IF(IsAttribute()) Attribute<ref modAttrs> } (. mod = mod ?? new List<FrameExpression>(); .)
[ FrameExpression<out fe> (. mod.Add(fe); .)
{ "," FrameExpression<out fe> (. mod.Add(fe); .)
}
] SYNC ";"
}
.
Invariant<out MaybeFreeExpression/*!*/ invariant>
= (. bool isFree = false; Expression/*!*/ e; List<string> ids = new List<string>(); invariant = null; Attributes attrs = null; .)
SYNC
["free" (. isFree = true; .)
]
"invariant" { IF(IsAttribute()) Attribute<ref attrs> } Expression<out e> (. invariant = new MaybeFreeExpression(e, isFree, attrs); .)
.
DecreasesList<.List<Expression/*!*/> decreases, bool allowWildcard.>
= (. Expression/*!*/ e; .)
PossiblyWildExpression<out e> (. if (!allowWildcard && e is WildcardExpr) {
SemErr(e.tok, "'decreases *' is only allowed on loops");
} else {
decreases.Add(e);
}
.)
{ "," PossiblyWildExpression<out e> (. if (!allowWildcard && e is WildcardExpr) {
SemErr(e.tok, "'decreases *' is only allowed on loops");
} else {
decreases.Add(e);
}
.)
}
.
Guard<out Expression e> /* null represents demonic-choice */
= (. Expression/*!*/ ee; e = null; .)
"("
( "*" (. e = null; .)
| Expression<out ee> (. e = ee; .)
)
")"
.
MatchStmt<out Statement/*!*/ s>
= (. Contract.Ensures(Contract.ValueAtReturn(out s) != null);
Token x; Expression/*!*/ e; MatchCaseStmt/*!*/ c;
List<MatchCaseStmt/*!*/> cases = new List<MatchCaseStmt/*!*/>(); .)
"match" (. x = t; .)
Expression<out e>
"{"
{ CaseStatement<out c> (. cases.Add(c); .)
}
"}"
(. s = new MatchStmt(x, e, cases); .)
.
CaseStatement<out MatchCaseStmt/*!*/ c>
= (. Contract.Ensures(Contract.ValueAtReturn(out c) != null);
IToken/*!*/ x, id;
List<BoundVar/*!*/> arguments = new List<BoundVar/*!*/>();
BoundVar/*!*/ bv;
List<Statement/*!*/> body = new List<Statement/*!*/>();
.)
"case" (. x = t; .)
Ident<out id>
[ "("
IdentTypeOptional<out bv> (. arguments.Add(bv); .)
{ "," IdentTypeOptional<out bv> (. arguments.Add(bv); .)
}
")" ]
"=>"
{ Stmt<body> }
(. c = new MatchCaseStmt(x, id.val, arguments, body); .)
.
/*------------------------------------------------------------------------*/
AssertStmt<out Statement/*!*/ s>
= (. Contract.Ensures(Contract.ValueAtReturn(out s) != null); IToken/*!*/ x;
Expression/*!*/ e = null; Attributes attrs = null;
.)
"assert" (. x = t; s = null;.)
{ IF(IsAttribute()) Attribute<ref attrs> }
( Expression<out e>
| "..."
)
";"
(. if (e == null) {
s = new SkeletonStatement(new AssertStmt(x, new LiteralExpr(x, true), attrs), true, false);
} else {
s = new AssertStmt(x, e, attrs);
}
.)
.
AssumeStmt<out Statement/*!*/ s>
= (. Contract.Ensures(Contract.ValueAtReturn(out s) != null); IToken/*!*/ x; Expression/*!*/ e; .)
"assume" (. x = t; .)
Expression<out e> ";" (. s = new AssumeStmt(x, e); .)
.
PrintStmt<out Statement/*!*/ s>
= (. Contract.Ensures(Contract.ValueAtReturn(out s) != null); IToken/*!*/ x; Attributes.Argument/*!*/ arg;
List<Attributes.Argument/*!*/> args = new List<Attributes.Argument/*!*/>();
.)
"print" (. x = t; .)
AttributeArg<out arg> (. args.Add(arg); .)
{ "," AttributeArg<out arg> (. args.Add(arg); .)
}
";" (. s = new PrintStmt(x, args); .)
.
ParallelStmt<out Statement/*!*/ s>
= (. Contract.Ensures(Contract.ValueAtReturn(out s) != null);
IToken/*!*/ x;
List<BoundVar/*!*/> bvars = null;
Attributes attrs = null;
Expression range = null;
var ens = new List<MaybeFreeExpression/*!*/>();
bool isFree;
Expression/*!*/ e;
BlockStmt/*!*/ block;
IToken bodyStart, bodyEnd;
.)
"parallel" (. x = t; .)
"("
[ (. List<BoundVar/*!*/> bvarsX; Attributes attrsX; Expression rangeX; .)
QuantifierDomain<out bvarsX, out attrsX, out rangeX>
(. bvars = bvarsX; attrs = attrsX; range = rangeX;
.)
]
(. if (bvars == null) { bvars = new List<BoundVar>(); }
if (range == null) { range = new LiteralExpr(x, true); }
.)
")"
{ (. isFree = false; .)
[ "free" (. isFree = true; .)
]
"ensures" Expression<out e> ";" (. ens.Add(new MaybeFreeExpression(e, isFree)); .)
}
BlockStmt<out block, out bodyStart, out bodyEnd>
(. s = new ParallelStmt(x, bvars, attrs, range, ens, block); .)
.
/*------------------------------------------------------------------------*/
Expression<out Expression/*!*/ e>
=
EquivExpression<out e>
.
/*------------------------------------------------------------------------*/
EquivExpression<out Expression/*!*/ e0>
= (. Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x; Expression/*!*/ e1; .)
ImpliesExpression<out e0>
{ EquivOp (. x = t; .)
ImpliesExpression<out e1> (. e0 = new BinaryExpr(x, BinaryExpr.Opcode.Iff, e0, e1); .)
}
.
EquivOp = "<==>" | '\u21d4'.
/*------------------------------------------------------------------------*/
ImpliesExpression<out Expression/*!*/ e0>
= (. Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x; Expression/*!*/ e1; .)
LogicalExpression<out e0>
[ ImpliesOp (. x = t; .)
ImpliesExpression<out e1> (. e0 = new BinaryExpr(x, BinaryExpr.Opcode.Imp, e0, e1); .)
]
.
ImpliesOp = "==>" | '\u21d2'.
/*------------------------------------------------------------------------*/
LogicalExpression<out Expression/*!*/ e0>
= (. Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x; Expression/*!*/ e1; .)
RelationalExpression<out e0>
[ AndOp (. x = t; .)
RelationalExpression<out e1> (. e0 = new BinaryExpr(x, BinaryExpr.Opcode.And, e0, e1); .)
{ AndOp (. x = t; .)
RelationalExpression<out e1> (. e0 = new BinaryExpr(x, BinaryExpr.Opcode.And, e0, e1); .)
}
| OrOp (. x = t; .)
RelationalExpression<out e1> (. e0 = new BinaryExpr(x, BinaryExpr.Opcode.Or, e0, e1); .)
{ OrOp (. x = t; .)
RelationalExpression<out e1> (. e0 = new BinaryExpr(x, BinaryExpr.Opcode.Or, e0, e1); .)
}
]
.
AndOp = "&&" | '\u2227'.
OrOp = "||" | '\u2228'.
/*------------------------------------------------------------------------*/
RelationalExpression<out Expression/*!*/ e>
= (. Contract.Ensures(Contract.ValueAtReturn(out e) != null);
IToken x, firstOpTok = null; Expression e0, e1, acc = null; BinaryExpr.Opcode op;
List<Expression> chain = null;
List<BinaryExpr.Opcode> ops = null;
int kind = 0; // 0 ("uncommitted") indicates chain of ==, possibly with one !=
// 1 ("ascending") indicates chain of ==, <, <=, possibly with one !=
// 2 ("descending") indicates chain of ==, >, >=, possibly with one !=
// 3 ("illegal") indicates illegal chain
// 4 ("disjoint") indicates chain of disjoint set operators
bool hasSeenNeq = false;
.)
Term<out e0> (. e = e0; .)
[ RelOp<out x, out op> (. firstOpTok = x; .)
Term<out e1> (. e = new BinaryExpr(x, op, e0, e1);
if (op == BinaryExpr.Opcode.Disjoint)
acc = new BinaryExpr(x, BinaryExpr.Opcode.Add, e0, e1); // accumulate first two operands.
.)
{ (. if (chain == null) {
chain = new List<Expression>();
ops = new List<BinaryExpr.Opcode>();
chain.Add(e0); ops.Add(op); chain.Add(e1);
switch (op) {
case BinaryExpr.Opcode.Eq:
kind = 0; break;
case BinaryExpr.Opcode.Neq:
kind = 0; hasSeenNeq = true; break;
case BinaryExpr.Opcode.Lt:
case BinaryExpr.Opcode.Le:
kind = 1; break;
case BinaryExpr.Opcode.Gt:
case BinaryExpr.Opcode.Ge:
kind = 2; break;
case BinaryExpr.Opcode.Disjoint:
kind = 4; break;
default:
kind = 3; break;
}
}
e0 = e1;
.)
RelOp<out x, out op> (. switch (op) {
case BinaryExpr.Opcode.Eq:
if (kind != 0 && kind != 1 && kind != 2) { SemErr(x, "chaining not allowed from the previous operator"); }
break;
case BinaryExpr.Opcode.Neq:
if (hasSeenNeq) { SemErr(x, "a chain cannot have more than one != operator"); }
if (kind != 0 && kind != 1 && kind != 2) { SemErr(x, "this operator cannot continue this chain"); }
hasSeenNeq = true; break;
case BinaryExpr.Opcode.Lt:
case BinaryExpr.Opcode.Le:
if (kind == 0) { kind = 1; }
else if (kind != 1) { SemErr(x, "this operator chain cannot continue with an ascending operator"); }
break;
case BinaryExpr.Opcode.Gt:
case BinaryExpr.Opcode.Ge:
if (kind == 0) { kind = 2; }
else if (kind != 2) { SemErr(x, "this operator chain cannot continue with a descending operator"); }
break;
case BinaryExpr.Opcode.Disjoint:
if (kind != 4) { SemErr(x, "can only chain disjoint (!!) with itself."); kind = 3; }
break;
default:
SemErr(x, "this operator cannot be part of a chain");
kind = 3; break;
}
.)
Term<out e1> (. ops.Add(op); chain.Add(e1);
if (op == BinaryExpr.Opcode.Disjoint) {
e = new BinaryExpr(x, BinaryExpr.Opcode.And, e, new BinaryExpr(x, op, acc, e1));
acc = new BinaryExpr(x, BinaryExpr.Opcode.Add, acc, e1); //e0 has already been added.
}
else
e = new BinaryExpr(x, BinaryExpr.Opcode.And, e, new BinaryExpr(x, op, e0, e1));
.)
}
]
(. if (chain != null) {
e = new ChainingExpression(firstOpTok, chain, ops, e);
}
.)
.
RelOp<out IToken/*!*/ x, out BinaryExpr.Opcode op>
= (. Contract.Ensures(Contract.ValueAtReturn(out x) != null);
x = Token.NoToken; op = BinaryExpr.Opcode.Add/*(dummy)*/;
IToken y;
.)
( "==" (. x = t; op = BinaryExpr.Opcode.Eq; .)
| "<" (. x = t; op = BinaryExpr.Opcode.Lt; .)
| ">" (. x = t; op = BinaryExpr.Opcode.Gt; .)
| "<=" (. x = t; op = BinaryExpr.Opcode.Le; .)
| ">=" (. x = t; op = BinaryExpr.Opcode.Ge; .)
| "!=" (. x = t; op = BinaryExpr.Opcode.Neq; .)
| "!!" (. x = t; op = BinaryExpr.Opcode.Disjoint; .)
| "in" (. x = t; op = BinaryExpr.Opcode.In; .)
| /* The next operator is "!in", but Coco evidently parses "!in" even when it is a prefix of, say, "!initialized".
* The reason for this seems to be that the first character of "!in" is not a letter. So, here is the workaround:
*/
"!" (. x = t; y = Token.NoToken; .)
[ "in" (. y = t; .)
] (. if (y == Token.NoToken) {
SemErr(x, "invalid RelOp");
} else if (y.pos != x.pos + 1) {
SemErr(x, "invalid RelOp (perhaps you intended \"!in\" with no intervening whitespace?)");
} else {
x.val = "!in";
op = BinaryExpr.Opcode.NotIn;
}
.)
| '\u2260' (. x = t; op = BinaryExpr.Opcode.Neq; .)
| '\u2264' (. x = t; op = BinaryExpr.Opcode.Le; .)
| '\u2265' (. x = t; op = BinaryExpr.Opcode.Ge; .)
)
.
/*------------------------------------------------------------------------*/
Term<out Expression/*!*/ e0>
= (. Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x; Expression/*!*/ e1; BinaryExpr.Opcode op; .)
Factor<out e0>
{ AddOp<out x, out op>
Factor<out e1> (. e0 = new BinaryExpr(x, op, e0, e1); .)
}
.
AddOp<out IToken/*!*/ x, out BinaryExpr.Opcode op>
= (. Contract.Ensures(Contract.ValueAtReturn(out x) != null); x = Token.NoToken; op=BinaryExpr.Opcode.Add/*(dummy)*/; .)
( "+" (. x = t; op = BinaryExpr.Opcode.Add; .)
| "-" (. x = t; op = BinaryExpr.Opcode.Sub; .)
)
.
/*------------------------------------------------------------------------*/
Factor<out Expression/*!*/ e0>
= (. Contract.Ensures(Contract.ValueAtReturn(out e0) != null); IToken/*!*/ x; Expression/*!*/ e1; BinaryExpr.Opcode op; .)
UnaryExpression<out e0>
{ MulOp<out x, out op>
UnaryExpression<out e1> (. e0 = new BinaryExpr(x, op, e0, e1); .)
}
.
MulOp<out IToken/*!*/ x, out BinaryExpr.Opcode op>
= (. Contract.Ensures(Contract.ValueAtReturn(out x) != null); x = Token.NoToken; op = BinaryExpr.Opcode.Add/*(dummy)*/; .)
( "*" (. x = t; op = BinaryExpr.Opcode.Mul; .)
| "/" (. x = t; op = BinaryExpr.Opcode.Div; .)
| "%" (. x = t; op = BinaryExpr.Opcode.Mod; .)
)
.
/*------------------------------------------------------------------------*/
UnaryExpression<out Expression/*!*/ e>
= (. Contract.Ensures(Contract.ValueAtReturn(out e) != null); IToken/*!*/ x; e = dummyExpr; .)
( "-" (. x = t; .)
UnaryExpression<out e> (. e = new BinaryExpr(x, BinaryExpr.Opcode.Sub, new LiteralExpr(x, 0), e); .)
| NegOp (. x = t; .)
UnaryExpression<out e> (. e = new UnaryExpr(x, UnaryExpr.Opcode.Not, e); .)
| EndlessExpression<out e> /* these have no further suffix */
| DottedIdentifiersAndFunction<out e>
{ Suffix<ref e> }
| DisplayExpr<out e>
| MultiSetExpr<out e>
| MapExpr<out e>
| ConstAtomExpression<out e>
{ Suffix<ref e> }
)
.
Lhs<out Expression e>
= (. e = null; // to please the compiler
.)
( DottedIdentifiersAndFunction<out e>
{ Suffix<ref e> }
| ConstAtomExpression<out e>
Suffix<ref e>
{ Suffix<ref e> }
)
.
NegOp = "!" | '\u00ac'.
/* A ConstAtomExpression is never an l-value. Also, a ConstAtomExpression is never followed by
* an open paren (but could very well have a suffix that starts with a period or a square bracket).
* (The "Also..." part may change if expressions in Dafny could yield functions.)
*/
ConstAtomExpression<out Expression/*!*/ e>
= (. Contract.Ensures(Contract.ValueAtReturn(out e) != null);
IToken/*!*/ x; BigInteger n;
e = dummyExpr;
.)
( "false" (. e = new LiteralExpr(t, false); .)
| "true" (. e = new LiteralExpr(t, true); .)
| "null" (. e = new LiteralExpr(t); .)
| Nat<out n> (. e = new LiteralExpr(t, n); .)
| "this" (. e = new ThisExpr(t); .)
| "fresh" (. x = t; .)
"(" Expression<out e> ")" (. e = new FreshExpr(x, e); .)
| "allocated" (. x = t; .)
"(" Expression<out e> ")" (. e = new AllocatedExpr(x, e); .)
| "old" (. x = t; .)
"(" Expression<out e> ")" (. e = new OldExpr(x, e); .)
| "|" (. x = t; .)
Expression<out e> (. e = new UnaryExpr(x, UnaryExpr.Opcode.SeqLength, e); .)
"|"
| "(" (. x = t; .)
Expression<out e> (. e = new ParensExpression(x, e); .)
")"
)
.
DisplayExpr<out Expression e>
= (. Contract.Ensures(Contract.ValueAtReturn(out e) != null);
IToken/*!*/ x = null; List<Expression/*!*/>/*!*/ elements;
e = dummyExpr;
.)
( "{" (. x = t; elements = new List<Expression/*!*/>(); .)
[ Expressions<elements> ] (. e = new SetDisplayExpr(x, elements);.)
"}"
| "[" (. x = t; elements = new List<Expression/*!*/>(); .)
[ Expressions<elements> ] (. e = new SeqDisplayExpr(x, elements); .)
"]"
)
.
MultiSetExpr<out Expression e>
= (. Contract.Ensures(Contract.ValueAtReturn(out e) != null);
IToken/*!*/ x = null; List<Expression/*!*/>/*!*/ elements;
e = dummyExpr;
.)
"multiset" (. x = t; .)
( "{" (. elements = new List<Expression/*!*/>(); .)
[ Expressions<elements> ] (. e = new MultiSetDisplayExpr(x, elements);.)
"}"
| "(" (. x = t; elements = new List<Expression/*!*/>(); .)
Expression<out e> (. e = new MultiSetFormingExpr(x, e); .)
")"
| (. SemErr("multiset must be followed by multiset literal or expression to coerce in parentheses."); .)
)
.
MapExpr<out Expression e>
= (. Contract.Ensures(Contract.ValueAtReturn(out e) != null);
IToken/*!*/ x = null; List<ExpressionPair/*!*/>/*!*/ elements;
e = dummyExpr;
.)
"map" (. x = t; .)
( "{" (. elements = new List<ExpressionPair/*!*/>(); .)
[ MapLiteralExpressions<out elements> ] (. e = new MapDisplayExpr(x, elements);.)
"}"
| (. SemErr("map must be followed by braces."); .)
)
.
MapLiteralExpressions<.out List<ExpressionPair> elements.>
= (. Expression/*!*/ d, r;
elements = new List<ExpressionPair/*!*/>(); .)
Expression<out d> ":=" Expression<out r> (. elements.Add(new ExpressionPair(d,r)); .)
{ "," Expression<out d> ":=" Expression<out r>(. elements.Add(new ExpressionPair(d,r)); .)
}
.
EndlessExpression<out Expression e>
= (. IToken/*!*/ x;
Expression e0, e1;
e = dummyExpr;
BoundVar d;
List<BoundVar> letVars; List<Expression> letRHSs;
.)
( "if" (. x = t; .)
Expression<out e>
"then" Expression<out e0>
"else" Expression<out e1> (. e = new ITEExpr(x, e, e0, e1); .)
| MatchExpression<out e>
| QuantifierGuts<out e>
| ComprehensionExpr<out e>
| "assert" (. x = t; .)
Expression<out e0> ";"
Expression<out e1> (. e = new AssertExpr(x, e0, e1); .)
| "assume" (. x = t; .)
Expression<out e0> ";"
Expression<out e1> (. e = new AssumeExpr(x, e0, e1); .)
| "var" (. x = t;
letVars = new List<BoundVar>();
letRHSs = new List<Expression>(); .)
IdentTypeOptional<out d> (. letVars.Add(d); .)
{ "," IdentTypeOptional<out d> (. letVars.Add(d); .)
}
":="
Expression<out e> (. letRHSs.Add(e); .)
{ "," Expression<out e> (. letRHSs.Add(e); .)
}
";"
Expression<out e> (. e = new LetExpr(x, letVars, letRHSs, e); .)
)
.
MatchExpression<out Expression/*!*/ e>
= (. Contract.Ensures(Contract.ValueAtReturn(out e) != null); IToken/*!*/ x; MatchCaseExpr/*!*/ c;
List<MatchCaseExpr/*!*/> cases = new List<MatchCaseExpr/*!*/>();
.)
"match" (. x = t; .)
Expression<out e>
/* Note: The following gives rise to a '"case" is start & successor of deletable structure' error,
but it's okay, because we want this closer match expression to bind as much as possible--use
parens around it to limit its scope. */
{ CaseExpression<out c> (. cases.Add(c); .)
}
(. e = new MatchExpr(x, e, cases); .)
.
CaseExpression<out MatchCaseExpr/*!*/ c>
= (. Contract.Ensures(Contract.ValueAtReturn(out c) != null); IToken/*!*/ x, id;
List<BoundVar/*!*/> arguments = new List<BoundVar/*!*/>();
BoundVar/*!*/ bv;
Expression/*!*/ body;
.)
"case" (. x = t; .)
Ident<out id>
[ "("
IdentTypeOptional<out bv> (. arguments.Add(bv); .)
{ "," IdentTypeOptional<out bv> (. arguments.Add(bv); .)
}
")" ]
"=>"
Expression<out body> (. c = new MatchCaseExpr(x, id.val, arguments, body); .)
.
/*------------------------------------------------------------------------*/
DottedIdentifiersAndFunction<out Expression e>
= (. IToken id; IToken openParen = null;
List<Expression> args = null;
List<IToken> idents = new List<IToken>();
.)
Ident<out id> (. idents.Add(id); .)
{ "."
Ident<out id> (. idents.Add(id); .)
}
[ "(" (. openParen = t; args = new List<Expression>(); .)
[ Expressions<args> ]
")"
]
(. e = new IdentifierSequence(idents, openParen, args); .)
.
Suffix<ref Expression/*!*/ e>
= (. Contract.Requires(e != null); Contract.Ensures(e!=null); IToken/*!*/ id, x; List<Expression/*!*/>/*!*/ args;
Expression e0 = null; Expression e1 = null; Expression/*!*/ ee; bool anyDots = false;
List<Expression> multipleIndices = null;
bool func = false;
.)
( "."
Ident<out id>
[ "(" (. IToken openParen = t; args = new List<Expression/*!*/>(); func = true; .)
[ Expressions<args> ]
")" (. e = new FunctionCallExpr(id, id.val, e, openParen, args); .)
] (. if (!func) { e = new ExprDotName(id, e, id.val); } .)
| "[" (. x = t; .)
( Expression<out ee> (. e0 = ee; .)
( ".." (. anyDots = true; .)
[ Expression<out ee> (. e1 = ee; .)
]
| ":="
Expression<out ee> (. e1 = ee; .)
| { "," Expression<out ee> (. if (multipleIndices == null) {
multipleIndices = new List<Expression>();
multipleIndices.Add(e0);
}
multipleIndices.Add(ee);
.)
}
)
| ".." (. anyDots = true; .)
[ Expression<out ee> (. e1 = ee; .)
]
)
(. if (multipleIndices != null) {
e = new MultiSelectExpr(x, e, multipleIndices);
// make sure an array class with this dimensionality exists
UserDefinedType tmp = theBuiltIns.ArrayType(x, multipleIndices.Count, new IntType(), true);
} else {
if (!anyDots && e0 == null) {
/* a parsing error occurred */
e0 = dummyExpr;
}
Contract.Assert(anyDots || e0 != null);
if (anyDots) {
//Contract.Assert(e0 != null || e1 != null);
e = new SeqSelectExpr(x, false, e, e0, e1);
} else if (e1 == null) {
Contract.Assert(e0 != null);
e = new SeqSelectExpr(x, true, e, e0, null);
} else {
Contract.Assert(e0 != null);
e = new SeqUpdateExpr(x, e, e0, e1);
}
}
.)
"]"
)
.
/*------------------------------------------------------------------------*/
QuantifierGuts<out Expression/*!*/ q>
= (. Contract.Ensures(Contract.ValueAtReturn(out q) != null); IToken/*!*/ x = Token.NoToken;
bool univ = false;
List<BoundVar/*!*/> bvars;
Attributes attrs;
Expression range;
Expression/*!*/ body;
.)
( Forall (. x = t; univ = true; .)
| Exists (. x = t; .)
)
QuantifierDomain<out bvars, out attrs, out range>
QSep
Expression<out body>
(. if (univ) {
q = new ForallExpr(x, bvars, range, body, attrs);
} else {
q = new ExistsExpr(x, bvars, range, body, attrs);
}
.)
.
Forall = "forall" | '\u2200'.
Exists = "exists" | '\u2203'.
QSep = "::" | '\u2022'.
QuantifierDomain<.out List<BoundVar/*!*/> bvars, out Attributes attrs, out Expression range.>
= (.
bvars = new List<BoundVar/*!*/>();
BoundVar/*!*/ bv;
attrs = null;
range = null;
.)
IdentTypeOptional<out bv> (. bvars.Add(bv); .)
{ ","
IdentTypeOptional<out bv> (. bvars.Add(bv); .)
}
{ Attribute<ref attrs> }
[ "|"
Expression<out range>
]
.
ComprehensionExpr<out Expression/*!*/ q>
= (. Contract.Ensures(Contract.ValueAtReturn(out q) != null);
IToken/*!*/ x = Token.NoToken;
BoundVar/*!*/ bv;
List<BoundVar/*!*/> bvars = new List<BoundVar/*!*/>();
Expression/*!*/ range;
Expression body = null;
.)
"set" (. x = t; .)
IdentTypeOptional<out bv> (. bvars.Add(bv); .)
{ ","
IdentTypeOptional<out bv> (. bvars.Add(bv); .)
}
"|" Expression<out range>
[
QSep
Expression<out body>
]
(. if (body == null && bvars.Count != 1) { SemErr(t, "a set comprehension with more than one bound variable must have a term expression"); }
q = new SetComprehension(x, bvars, range, body);
.)
.
Expressions<.List<Expression/*!*/>/*!*/ args.>
= (. Contract.Requires(cce.NonNullElements(args)); Expression/*!*/ e; .)
Expression<out e> (. args.Add(e); .)
{ "," Expression<out e> (. args.Add(e); .)
}
.
/*------------------------------------------------------------------------*/
Attribute<ref Attributes attrs>
= "{"
AttributeBody<ref attrs>
"}"
.
AttributeBody<ref Attributes attrs>
= (. string aName;
List<Attributes.Argument/*!*/> aArgs = new List<Attributes.Argument/*!*/>();
Attributes.Argument/*!*/ aArg;
.)
":" ident (. aName = t.val; .)
[ AttributeArg<out aArg> (. aArgs.Add(aArg); .)
{ "," AttributeArg<out aArg> (. aArgs.Add(aArg); .)
}
] (. attrs = new Attributes(aName, aArgs, attrs); .)
.
AttributeArg<out Attributes.Argument/*!*/ arg>
= (. Contract.Ensures(Contract.ValueAtReturn(out arg) != null); Expression/*!*/ e; arg = dummyAttrArg; .)
( string (. arg = new Attributes.Argument(t, t.val.Substring(1, t.val.Length-2)); .)
| Expression<out e> (. arg = new Attributes.Argument(t, e); .)
)
.
/*------------------------------------------------------------------------*/
Idents<.List<string/*!*/>/*!*/ ids.>
= (. IToken/*!*/ id; .)
Ident<out id> (. ids.Add(id.val); .)
{ "," Ident<out id> (. ids.Add(id.val); .)
}
.
Ident<out IToken/*!*/ x>
= (. Contract.Ensures(Contract.ValueAtReturn(out x) != null); .)
ident (. x = t; .)
.
Nat<out BigInteger n>
=
digits
(. try {
n = BigInteger.Parse(t.val);
} catch (System.FormatException) {
SemErr("incorrectly formatted number");
n = BigInteger.Zero;
}
.)
.
END Dafny.
|