foundationdb/flow/actorcompiler/ActorParser.cs

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/*
* ActorParser.cs
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
namespace actorcompiler
{
class Error : Exception
{
public int SourceLine { get; private set; }
public Error(int SourceLine, string format, params object[] args)
: base(string.Format(format,args))
{
this.SourceLine = SourceLine;
}
};
class Token
{
public string Value;
public int Position;
public int SourceLine;
public int BraceDepth;
public int ParenDepth;
public bool IsWhitespace { get { return Value == " " || Value == "\n" || Value == "\r" || Value == "\r\n" || Value == "\t" || Value.StartsWith("//") || Value.StartsWith("/*"); } }
public override string ToString() { return Value; }
public Token Assert(string error, Func<Token, bool> pred)
{
if (!pred(this)) throw new Error(SourceLine, error);
return this;
}
public TokenRange GetMatchingRangeIn(TokenRange range)
{
Func<Token,bool> pred;
int dir;
switch (Value) {
case "(": pred = t=> t.Value != ")" || t.ParenDepth != ParenDepth; dir = +1; break;
case ")": pred = t=> t.Value != "(" || t.ParenDepth != ParenDepth; dir = -1; break;
case "{": pred = t=> t.Value != "}" || t.BraceDepth != BraceDepth; dir = +1; break;
case "}": pred = t=> t.Value != "{" || t.BraceDepth != BraceDepth; dir = -1; break;
case "<": return
new TokenRange(range.GetAllTokens(),
Position+1,
AngleBracketParser.NotInsideAngleBrackets(
new TokenRange(range.GetAllTokens(), Position, range.End))
.Skip(1) // skip the "<", which is considered "outside"
.First() // get the ">", which is likewise "outside"
.Position);
default: throw new NotSupportedException("Can't match this token!");
}
TokenRange r;
if (dir == -1)
{
r = new TokenRange(range.GetAllTokens(), range.Begin, Position)
.RevTakeWhile(pred);
if (r.Begin == range.Begin)
throw new Error(SourceLine, "Syntax error: Unmatched " + Value);
}
else
{
r = new TokenRange(range.GetAllTokens(), Position+1, range.End)
.TakeWhile(pred);
if (r.End == range.End)
throw new Error(SourceLine, "Syntax error: Unmatched " + Value);
}
return r;
}
};
class TokenRange : IEnumerable<Token>
{
public TokenRange(Token[] tokens, int beginPos, int endPos)
{
if (beginPos > endPos) throw new InvalidOperationException("Invalid TokenRange");
this.tokens = tokens;
this.beginPos = beginPos;
this.endPos = endPos;
}
public bool IsEmpty { get { return beginPos==endPos; } }
public int Begin { get { return beginPos; } }
public int End { get { return endPos; } }
public Token First() {
if (beginPos == endPos) throw new InvalidOperationException("Empty TokenRange");
return tokens[beginPos];
}
public Token Last() {
if (beginPos == endPos) throw new InvalidOperationException("Empty TokenRange");
return tokens[endPos - 1];
}
public Token Last(Func<Token, bool> pred)
{
for (int i = endPos - 1; i >= beginPos; i--)
if (pred(tokens[i]))
return tokens[i];
throw new Exception("Matching token not found");
}
public TokenRange Skip(int count)
{
return new TokenRange(tokens, beginPos + count, endPos);
}
public TokenRange Consume(string value)
{
First().Assert("Expected " + value, t => t.Value == value);
return Skip(1);
}
public TokenRange Consume(string error, Func<Token, bool> pred)
{
First().Assert(error, pred);
return Skip(1);
}
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() { return GetEnumerator(); }
public IEnumerator<Token> GetEnumerator()
{
for (int i = beginPos; i < endPos; i++)
yield return tokens[i];
}
public TokenRange SkipWhile(Func<Token, bool> pred)
{
for (int e = beginPos; e < endPos; e++)
if (!pred(tokens[e]))
return new TokenRange(tokens, e, endPos);
return new TokenRange(tokens, endPos, endPos);
}
public TokenRange TakeWhile(Func<Token, bool> pred)
{
for (int e = beginPos; e < endPos; e++)
if (!pred(tokens[e]))
return new TokenRange(tokens, beginPos, e);
return new TokenRange(tokens, beginPos, endPos);
}
public TokenRange RevTakeWhile(Func<Token, bool> pred)
{
for (int e = endPos-1; e >= beginPos; e--)
if (!pred(tokens[e]))
return new TokenRange(tokens, e+1, endPos);
return new TokenRange(tokens, beginPos, endPos);
}
public TokenRange RevSkipWhile(Func<Token, bool> pred)
{
for (int e = endPos - 1; e >= beginPos; e--)
if (!pred(tokens[e]))
return new TokenRange(tokens, beginPos, e + 1);
return new TokenRange(tokens, beginPos, beginPos);
}
public Token[] GetAllTokens() { return tokens; }
Token[] tokens;
int beginPos;
int endPos;
};
static class AngleBracketParser
{
public static IEnumerable<Token> NotInsideAngleBrackets(IEnumerable<Token> tokens)
{
int AngleDepth = 0;
int? BasePD = null;
foreach (var tok in tokens)
{
if (BasePD == null) BasePD = tok.ParenDepth;
if (tok.ParenDepth == BasePD && tok.Value == ">") AngleDepth--;
if (AngleDepth == 0)
yield return tok;
if (tok.ParenDepth == BasePD && tok.Value == "<") AngleDepth++;
}
}
};
class ActorParser
{
public bool LineNumbersEnabled = true;
Token[] tokens;
string sourceFile;
public ActorParser(string text, string sourceFile)
{
this.sourceFile = sourceFile;
tokens = Tokenize(text).Select(t=>new Token{ Value=t }).ToArray();
CountParens();
//if (sourceFile.EndsWith(".h")) LineNumbersEnabled = false;
//Console.WriteLine("{0} chars -> {1} tokens", text.Length, tokens.Length);
//showTokens();
}
public void Write(System.IO.TextWriter writer, string destFileName)
{
writer.NewLine = "\n";
writer.WriteLine("#define POST_ACTOR_COMPILER 1");
int outLine = 1;
if (LineNumbersEnabled)
{
writer.WriteLine("#line {0} \"{1}\"", tokens[0].SourceLine, sourceFile);
outLine++;
}
int inBlocks = 0;
for(int i=0; i<tokens.Length; i++)
{
if(tokens[0].SourceLine == 0)
{
throw new Exception("Internal error: Invalid source line (0)");
}
if (tokens[i].Value == "ACTOR" || tokens[i].Value == "TEST_CASE")
{
int end;
var actor = ParseActor(i, out end);
var actorWriter = new System.IO.StringWriter();
actorWriter.NewLine = "\n";
new ActorCompiler(actor, sourceFile, inBlocks==0, LineNumbersEnabled).Write(actorWriter);
string[] actorLines = actorWriter.ToString().Split('\n');
bool hasLineNumber = false;
bool hadLineNumber = true;
foreach (var line in actorLines)
{
if (LineNumbersEnabled)
{
bool isLineNumber = line.Contains("#line");
if (isLineNumber) hadLineNumber = true;
if (!isLineNumber && !hasLineNumber && hadLineNumber)
{
writer.WriteLine("\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t#line {0} \"{1}\"", outLine + 1, destFileName);
outLine++;
hadLineNumber = false;
}
hasLineNumber = isLineNumber;
}
writer.WriteLine(line.TrimEnd('\n','\r'));
outLine++;
}
i = end;
if (i != tokens.Length && LineNumbersEnabled)
{
writer.WriteLine("#line {0} \"{1}\"", tokens[i].SourceLine, sourceFile);
outLine++;
}
}
else if (tokens[i].Value == "DESCR")
{
int end;
var descr = ParseDescr(i, out end);
int lines;
new DescrCompiler(descr, sourceFile, inBlocks == 0, tokens[i].BraceDepth).Write(writer, out lines);
i = end;
outLine += lines;
if (i != tokens.Length && LineNumbersEnabled)
{
writer.WriteLine("#line {0} \"{1}\"", tokens[i].SourceLine, sourceFile);
outLine++;
}
}
else
{
if (tokens[i].Value == "{") inBlocks++;
else if (tokens[i].Value == "}") inBlocks--;
writer.Write(tokens[i].Value);
outLine += tokens[i].Value.Count(c => c == '\n');
}
}
}
IEnumerable<TokenRange> SplitParameterList( TokenRange toks, string delimiter ) {
if (toks.Begin==toks.End) yield break;
while (true) {
Token comma = AngleBracketParser.NotInsideAngleBrackets( toks )
.FirstOrDefault( t=> t.Value==delimiter && t.ParenDepth == toks.First().ParenDepth );
if (comma == null) break;
yield return range(toks.Begin,comma.Position);
toks = range(comma.Position + 1, toks.End);
}
yield return toks;
}
IEnumerable<Token> NormalizeWhitespace(IEnumerable<Token> tokens)
{
bool inWhitespace = false;
bool leading = true;
foreach (var tok in tokens)
{
if (!tok.IsWhitespace)
{
if (inWhitespace && !leading) yield return new Token { Value = " " };
inWhitespace = false;
yield return tok;
leading = false;
}
else
{
inWhitespace = true;
}
}
}
void ParseDeclaration(TokenRange tokens,
out Token name,
out TokenRange type,
out TokenRange initializer,
out bool constructorSyntax)
{
initializer = null;
TokenRange beforeInitializer = tokens;
constructorSyntax = false;
Token equals = AngleBracketParser.NotInsideAngleBrackets(tokens)
.FirstOrDefault(t => t.Value == "=" && t.ParenDepth == tokens.First().ParenDepth);
if (equals != null)
{
// type name = initializer;
beforeInitializer = range(tokens.Begin,equals.Position);
initializer = range(equals.Position + 1, tokens.End);
}
else
{
Token paren = AngleBracketParser.NotInsideAngleBrackets(tokens)
.FirstOrDefault(t => t.Value == "(");
if (paren != null)
{
// type name(initializer);
constructorSyntax = true;
beforeInitializer = range(tokens.Begin, paren.Position);
initializer =
range(paren.Position + 1, tokens.End)
.TakeWhile(t => t.ParenDepth > paren.ParenDepth);
}
}
name = beforeInitializer.Last(NonWhitespace);
if (beforeInitializer.Begin == name.Position)
throw new Error(beforeInitializer.First().SourceLine, "Declaration has no type.");
type = range(beforeInitializer.Begin, name.Position);
}
VarDeclaration ParseVarDeclaration(TokenRange tokens)
{
Token name;
TokenRange type, initializer;
bool constructorSyntax;
ParseDeclaration( tokens, out name, out type, out initializer, out constructorSyntax );
return new VarDeclaration
{
name = name.Value,
type = str(NormalizeWhitespace(type)),
initializer = initializer == null ? "" : str(NormalizeWhitespace(initializer)),
initializerConstructorSyntax = constructorSyntax
};
}
readonly Func<Token, bool> Whitespace = (Token t) => t.IsWhitespace;
readonly Func<Token, bool> NonWhitespace = (Token t) => !t.IsWhitespace;
void ParseDescrHeading(Descr descr, TokenRange toks)
{
toks.First(NonWhitespace).Assert("non-struct DESCR!", t => t.Value == "struct");
toks = toks.SkipWhile(Whitespace).Skip(1).SkipWhile(Whitespace);
var colon = toks.FirstOrDefault(t => t.Value == ":");
if (colon != null)
{
descr.superClassList = str(range(colon.Position + 1, toks.End)).Trim();
toks = range(toks.Begin, colon.Position);
}
descr.name = str(toks).Trim();
}
void ParseTestCaseHeading(Actor actor, TokenRange toks)
{
actor.isStatic = true;
// The parameter(s) to the TEST_CASE macro are opaque to the actor compiler
TokenRange paramRange = toks.Last(NonWhitespace)
.Assert("Unexpected tokens after test case parameter list.",
t => t.Value == ")" && t.ParenDepth == toks.First().ParenDepth)
.GetMatchingRangeIn(toks);
actor.testCaseParameters = str(paramRange);
actor.name = "flowTestCase" + toks.First().SourceLine;
actor.parameters = new VarDeclaration[] { };
actor.returnType = "Void";
}
void ParseActorHeading(Actor actor, TokenRange toks)
{
var template = toks.First(NonWhitespace);
if (template.Value == "template")
{
var templateParams = range(template.Position+1, toks.End)
.First(NonWhitespace)
.Assert("Invalid template declaration", t=>t.Value=="<")
.GetMatchingRangeIn(toks);
actor.templateFormals = SplitParameterList(templateParams, ",")
.Select(p => ParseVarDeclaration(p)) //< SOMEDAY: ?
.ToArray();
toks = range(templateParams.End + 1, toks.End);
}
var staticKeyword = toks.First(NonWhitespace);
if (staticKeyword.Value == "static")
{
actor.isStatic = true;
toks = range(staticKeyword.Position + 1, toks.End);
}
var uncancellableKeyword = toks.First(NonWhitespace);
if (uncancellableKeyword.Value == "UNCANCELLABLE")
{
actor.isUncancellable = true;
toks = range(uncancellableKeyword.Position + 1, toks.End);
}
// Find the parameter list
TokenRange paramRange = toks.Last(NonWhitespace)
.Assert("Unexpected tokens after actor parameter list.",
t => t.Value == ")" && t.ParenDepth == toks.First().ParenDepth)
.GetMatchingRangeIn(toks);
actor.parameters = SplitParameterList(paramRange, ",")
.Select(p => ParseVarDeclaration(p))
.ToArray();
var name = range(toks.Begin,paramRange.Begin-1).Last(NonWhitespace);
actor.name = name.Value;
// SOMEDAY: refactor?
var returnType = range(toks.First().Position + 1, name.Position).SkipWhile(Whitespace);
var retToken = returnType.First();
if (retToken.Value == "Future")
{
var ofType = returnType.Skip(1).First(NonWhitespace).Assert("Expected <", tok => tok.Value == "<").GetMatchingRangeIn(returnType);
actor.returnType = str(NormalizeWhitespace(ofType));
toks = range(ofType.End + 1, returnType.End);
}
else if (retToken.Value == "void"/* && !returnType.Skip(1).Any(NonWhitespace)*/)
{
actor.returnType = null;
toks = returnType.Skip(1);
}
else
throw new Error(actor.SourceLine, "Actor apparently does not return Future<T>");
toks = toks.SkipWhile(Whitespace);
if (!toks.IsEmpty)
{
if (toks.Last().Value == "::")
{
actor.nameSpace = str(range(toks.Begin, toks.End - 1));
}
else
{
Console.WriteLine("Tokens: '{0}' {1} '{2}'", str(toks), toks.Count(), toks.Last().Value);
throw new Error(actor.SourceLine, "Unrecognized tokens preceding parameter list in actor declaration");
}
}
}
LoopStatement ParseLoopStatement(TokenRange toks)
{
return new LoopStatement {
body = ParseCompoundStatement( toks.Consume("loop") )
};
}
ChooseStatement ParseChooseStatement(TokenRange toks)
{
return new ChooseStatement
{
body = ParseCompoundStatement(toks.Consume("choose"))
};
}
WhenStatement ParseWhenStatement(TokenRange toks)
{
var expr = toks.Consume("when")
.First(NonWhitespace)
.Assert("Expected (", t => t.Value == "(")
.GetMatchingRangeIn(toks);
return new WhenStatement {
wait = ParseWaitStatement(expr),
body = ParseCompoundStatement(range(expr.End+1, toks.End))
};
}
StateDeclarationStatement ParseStateDeclaration(TokenRange toks)
{
toks = toks.Consume("state").RevSkipWhile(t => t.Value == ";");
return new StateDeclarationStatement {
decl = ParseVarDeclaration(toks)
};
}
ReturnStatement ParseReturnStatement(TokenRange toks)
{
toks = toks.Consume("return").RevSkipWhile(t => t.Value == ";");
return new ReturnStatement
{
expression = str(NormalizeWhitespace(toks))
};
}
ThrowStatement ParseThrowStatement(TokenRange toks)
{
toks = toks.Consume("throw").RevSkipWhile(t => t.Value == ";");
return new ThrowStatement
{
expression = str(NormalizeWhitespace(toks))
};
}
WaitStatement ParseWaitStatement(TokenRange toks)
{
WaitStatement ws = new WaitStatement();
ws.FirstSourceLine = toks.First().SourceLine;
if (toks.First().Value == "state")
{
ws.resultIsState = true;
toks = toks.Consume("state");
}
Token name;
TokenRange type, initializer;
bool constructorSyntax;
ParseDeclaration( toks.RevSkipWhile(t=>t.Value==";"), out name, out type, out initializer, out constructorSyntax );
ws.result = new VarDeclaration
{
name = name.Value,
type = str(NormalizeWhitespace(type)),
initializer = "",
initializerConstructorSyntax = false
};
if (initializer == null) throw new Error(ws.FirstSourceLine, "Wait statement must be a declaration");
var waitParams = initializer
.SkipWhile(Whitespace).Consume("Statement contains a wait, but is not a valid wait statement or a supported compound statement.",
t=> {
if (t.Value=="wait") return true;
if (t.Value=="waitNext") { ws.isWaitNext = true; return true; }
return false;
})
.SkipWhile(Whitespace).First().Assert("Expected (", t => t.Value == "(")
.GetMatchingRangeIn(initializer);
if (!range(waitParams.End, initializer.End).Consume(")").All(Whitespace))
throw new Error(toks.First().SourceLine, "Statement contains a wait, but is not a valid wait statement or a supported compound statement.");
ws.futureExpression = str(NormalizeWhitespace(waitParams));
return ws;
}
WhileStatement ParseWhileStatement(TokenRange toks)
{
var expr = toks.Consume("while")
.First(NonWhitespace)
.Assert("Expected (", t => t.Value == "(")
.GetMatchingRangeIn(toks);
return new WhileStatement
{
expression = str(NormalizeWhitespace(expr)),
body = ParseCompoundStatement(range(expr.End + 1, toks.End))
};
}
Statement ParseForStatement(TokenRange toks)
{
var head =
toks.Consume("for")
.First(NonWhitespace)
.Assert("Expected (", t => t.Value == "(")
.GetMatchingRangeIn(toks);
Token[] delim =
head.Where(
t => t.ParenDepth == head.First().ParenDepth &&
t.BraceDepth == head.First().BraceDepth &&
t.Value==";"
).ToArray();
if (delim.Length == 2)
{
var init = range(head.Begin, delim[0].Position);
var cond = range(delim[0].Position + 1, delim[1].Position);
var next = range(delim[1].Position + 1, head.End);
var body = range(head.End + 1, toks.End);
return new ForStatement
{
initExpression = str(NormalizeWhitespace(init)),
condExpression = str(NormalizeWhitespace(cond)),
nextExpression = str(NormalizeWhitespace(next)),
body = ParseCompoundStatement(body)
};
}
delim =
head.Where(
t => t.ParenDepth == head.First().ParenDepth &&
t.BraceDepth == head.First().BraceDepth &&
t.Value == ":"
).ToArray();
if (delim.Length != 1)
{
throw new Error(head.First().SourceLine, "for statement must be 3-arg style or c++11 2-arg style");
}
return new RangeForStatement
{
// The container over which to iterate
rangeExpression = str(NormalizeWhitespace(range(delim[0].Position + 1, head.End).SkipWhile(Whitespace))),
// Type and name of the variable assigned in each iteration
rangeDecl = str(NormalizeWhitespace(range(head.Begin, delim[0].Position - 1).SkipWhile(Whitespace))),
// The body of the for loop
body = ParseCompoundStatement(range(head.End + 1, toks.End))
};
}
Statement ParseIfStatement(TokenRange toks)
{
var expr = toks.Consume("if")
.First(NonWhitespace)
.Assert("Expected (", t => t.Value == "(")
.GetMatchingRangeIn(toks);
return new IfStatement {
expression = str(NormalizeWhitespace(expr)),
ifBody = ParseCompoundStatement(range(expr.End+1, toks.End))
// elseBody will be filled in later if necessary by ParseElseStatement
};
}
void ParseElseStatement(TokenRange toks, Statement prevStatement)
{
var ifStatement = prevStatement as IfStatement;
while (ifStatement != null && ifStatement.elseBody != null)
ifStatement = ifStatement.elseBody as IfStatement;
if (ifStatement == null)
throw new Error(toks.First().SourceLine, "else without matching if");
ifStatement.elseBody = ParseCompoundStatement(toks.Consume("else"));
}
Statement ParseTryStatement(TokenRange toks)
{
return new TryStatement
{
tryBody = ParseCompoundStatement(toks.Consume("try")),
catches = new List<TryStatement.Catch>() // will be filled in later by ParseCatchStatement
};
}
void ParseCatchStatement(TokenRange toks, Statement prevStatement)
{
var tryStatement = prevStatement as TryStatement;
if (tryStatement == null)
throw new Error(toks.First().SourceLine, "catch without matching try");
var expr = toks.Consume("catch")
.First(NonWhitespace)
.Assert("Expected (", t => t.Value == "(")
.GetMatchingRangeIn(toks);
tryStatement.catches.Add(
new TryStatement.Catch
{
expression = str(NormalizeWhitespace(expr)),
body = ParseCompoundStatement(range(expr.End + 1, toks.End)),
FirstSourceLine = expr.First().SourceLine
});
}
static readonly HashSet<string> IllegalKeywords = new HashSet<string> { "goto", "do", "finally", "__if_exists", "__if_not_exists" };
void ParseDeclaration(TokenRange toks, List<Declaration> declarations)
{
Declaration dec = new Declaration();
Token delim = toks.First(t => t.Value == ";");
var nameRange = range(toks.Begin, delim.Position).RevSkipWhile(Whitespace).RevTakeWhile(NonWhitespace);
var typeRange = range(toks.Begin, nameRange.Begin);
var commentRange = range(delim.Position + 1, toks.End);
dec.name = str(nameRange).Trim();
dec.type = str(typeRange).Trim();
dec.comment = str(commentRange).Trim().TrimStart('/');
declarations.Add(dec);
}
void ParseStatement(TokenRange toks, List<Statement> statements)
{
toks = toks.SkipWhile(Whitespace);
Action<Statement> Add = stmt =>
{
stmt.FirstSourceLine = toks.First().SourceLine;
statements.Add(stmt);
};
switch (toks.First().Value)
{
case "loop": Add(ParseLoopStatement(toks)); break;
case "while": Add(ParseWhileStatement(toks)); break;
case "for": Add(ParseForStatement(toks)); break;
case "break": Add(new BreakStatement()); break;
case "continue": Add(new ContinueStatement()); break;
case "return": Add(ParseReturnStatement(toks)); break;
case "{": Add(ParseCompoundStatement(toks)); break;
case "if": Add(ParseIfStatement(toks)); break;
case "else": ParseElseStatement(toks, statements[statements.Count - 1]); break;
case "choose": Add(ParseChooseStatement(toks)); break;
case "when": Add(ParseWhenStatement(toks)); break;
case "try": Add(ParseTryStatement(toks)); break;
case "catch": ParseCatchStatement(toks, statements[statements.Count - 1]); break;
case "throw": Add(ParseThrowStatement(toks)); break;
default:
if (IllegalKeywords.Contains(toks.First().Value))
throw new Error(toks.First().SourceLine, "Statement '{0}' not supported in actors.", toks.First().Value);
if (toks.Any(t => t.Value == "wait" || t.Value == "waitNext"))
Add(ParseWaitStatement(toks));
else if (toks.First().Value == "state")
Add(ParseStateDeclaration(toks));
else if (toks.First().Value == "switch" && toks.Any(t => t.Value == "return"))
throw new Error(toks.First().SourceLine, "Unsupported compound statement containing return.");
else if (toks.RevSkipWhile(t => t.Value == ";").Any(NonWhitespace))
Add(new PlainOldCodeStatement
{
code = str(NormalizeWhitespace(toks.RevSkipWhile(t => t.Value == ";"))) + ";"
});
break;
};
}
Statement ParseCompoundStatement(TokenRange toks)
{
var first = toks.First(NonWhitespace);
if (first.Value == "{") {
var inBraces = first.GetMatchingRangeIn(toks);
if (!range(inBraces.End, toks.End).Consume("}").All(Whitespace))
throw new Error(inBraces.Last().SourceLine, "Unexpected tokens after compound statement");
return ParseCodeBlock(inBraces);
} else {
List<Statement> statements = new List<Statement>();
ParseStatement( toks.Skip(1), statements );
return statements[0];
}
}
List<Declaration> ParseDescrCodeBlock(TokenRange toks)
{
List<Declaration> declarations = new List<Declaration>();
while (true)
{
Token delim = toks.FirstOrDefault(t => t.Value == ";");
if (delim == null)
break;
int pos = delim.Position + 1;
var potentialComment = range(pos, toks.End).SkipWhile(t => t.Value == "\t" || t.Value == " ");
if (!potentialComment.IsEmpty && potentialComment.First().Value.StartsWith("//"))
{
pos = potentialComment.First().Position + 1;
}
ParseDeclaration(range(toks.Begin, pos), declarations);
toks = range(pos, toks.End);
}
if (!toks.All(Whitespace))
throw new Error(toks.First(NonWhitespace).SourceLine, "Trailing unterminated statement in code block");
return declarations;
}
CodeBlock ParseCodeBlock(TokenRange toks)
{
List<Statement> statements = new List<Statement>();
while (true)
{
Token delim = toks
.FirstOrDefault(
t=> t.ParenDepth == toks.First().ParenDepth &&
t.BraceDepth == toks.First().BraceDepth &&
(t.Value==";" || t.Value == "}")
);
if (delim == null)
break;
ParseStatement(range(toks.Begin, delim.Position + 1), statements);
toks = range(delim.Position + 1, toks.End);
}
if (!toks.All(Whitespace))
throw new Error(toks.First(NonWhitespace).SourceLine, "Trailing unterminated statement in code block");
return new CodeBlock { statements = statements.ToArray() };
}
TokenRange range(int beginPos, int endPos)
{
return new TokenRange(tokens, beginPos, endPos);
}
Descr ParseDescr(int pos, out int end)
{
var descr = new Descr();
var toks = range(pos + 1, tokens.Length);
var heading = toks.TakeWhile(t => t.Value != "{");
var body = range(heading.End + 1, tokens.Length)
.TakeWhile(t => t.BraceDepth > toks.First().BraceDepth || t.Value == ";" ); //assumes no whitespace between the last "}" and the ";"
ParseDescrHeading(descr, heading);
descr.body = ParseDescrCodeBlock(body);
end = body.End + 1;
return descr;
}
Actor ParseActor( int pos, out int end ) {
var actor = new Actor();
var head_token = tokens[pos];
actor.SourceLine = head_token.SourceLine;
var toks = range(pos+1, tokens.Length);
var heading = toks.TakeWhile(t => t.Value != "{");
var body = range(heading.End+1, tokens.Length)
.TakeWhile(t => t.BraceDepth > toks.First().BraceDepth);
if (head_token.Value == "ACTOR")
ParseActorHeading(actor, heading);
else if (head_token.Value == "TEST_CASE")
ParseTestCaseHeading(actor, heading);
else
head_token.Assert("ACTOR or TEST_CASE expected!", t => false);
actor.body = ParseCodeBlock(body);
if (!actor.body.containsWait())
Console.Error.WriteLine("{0}:{1}: warning: ACTOR {2} does not contain a wait() statement", sourceFile, actor.SourceLine, actor.name);
end = body.End + 1;
return actor;
}
string str(IEnumerable<Token> tokens)
{
return string.Join("", tokens.Select(x => x.Value).ToArray());
}
string str(int begin, int end)
{
return str(range(begin,end));
}
void CountParens()
{
int BraceDepth = 0, ParenDepth = 0, LineCount = 1;
Token lastParen = null, lastBrace = null;
for (int i = 0; i < tokens.Length; i++)
{
switch (tokens[i].Value)
{
case "}": BraceDepth--; break;
case ")": ParenDepth--; break;
case "\r\n": LineCount++; break;
case "\n": LineCount++; break;
}
if (tokens[i].Value.StartsWith("/*")) LineCount += tokens[i].Value.Count(c=>c=='\n');
if (BraceDepth < 0) throw new Error(LineCount, "Mismatched braces");
if (ParenDepth < 0) throw new Error(LineCount, "Mismatched parenthesis");
tokens[i].Position = i;
tokens[i].SourceLine = LineCount;
tokens[i].BraceDepth = BraceDepth;
tokens[i].ParenDepth = ParenDepth;
switch (tokens[i].Value)
{
case "{": BraceDepth++; if (BraceDepth==1) lastBrace = tokens[i]; break;
case "(": ParenDepth++; if (ParenDepth==1) lastParen = tokens[i]; break;
}
}
if (BraceDepth != 0) throw new Error(lastBrace.SourceLine, "Unmatched brace");
if (ParenDepth != 0) throw new Error(lastParen.SourceLine, "Unmatched parenthesis");
}
void showTokens()
{
foreach (var t in tokens)
{
if (t.Value == "\r\n")
Console.WriteLine();
else if (t.Value.Length == 1)
Console.Write(t.Value);
else
Console.Write("|{0}|", t.Value);
}
}
readonly Regex[] tokenExpressions = (new string[] {
@"\{",
@"\}",
@"\(",
@"\)",
@"//[^\n]*",
@"/[*]([*][^/]|[^*])*[*]/",
@"'(\\.|[^\'\n])*'", //< SOMEDAY: Not fully restrictive
@"""(\\.|[^\""\n])*""",
@"[a-zA-Z_][a-zA-Z_0-9]*",
@"\r\n",
@"\n",
@"::",
@"."
}).Select( x=>new Regex(@"\G"+x, RegexOptions.Singleline) ).ToArray();
IEnumerable<string> Tokenize(string text)
{
int pos = 0;
while (pos < text.Length)
{
bool ok = false;
foreach (var re in tokenExpressions)
{
var m = re.Match(text, pos);
if (m.Success)
{
yield return m.Value;
pos += m.Value.Length;
ok = true;
break;
}
}
if (!ok)
throw new Exception( String.Format("Can't tokenize! {0}", pos));
}
}
}
}