public void AddStatement(Statement s)
{
AddChild(s);
}
private StatementSequence ToStatementSequence(Statement s)
{
if (s is StatementSequence) {
return (StatementSequence)s;
} else {
StatementSequence seq = new StatementSequence();
seq.AddStatement(s);
return seq;
}
}
public virtual void Visit(Statement node)
{
}
void Stmt(out Statement stmt)
{
Expression exp = null;
stmt = null;
int sl = la.line, sc = la.col;
StatementSequence stmtSeq;
Token bf;
switch (la.kind) {
case 1: {
AssignStmt(out stmt);
stmt.AddSequencePoint(sl,sc, t.line,t.col+t.val.Length);
break;
}
case 13: {
Get();
stmt = new Skip();stmt.AddSequencePoint(t);
break;
}
case 3: {
BlockStmt(out stmt);
break;
}
case 18: {
IfStmt(out stmt);
break;
}
case 22: {
WhileStmt(out stmt);
break;
}
case 15: {
ReadStmt(out stmt);
stmt.AddSequencePoint(sl,sc, t.line,t.col+t.val.Length);
break;
}
case 14: {
Get();
Expr(out exp);
stmt = new Write(exp); stmt.AddSequencePoint(sl,sc, t.line,t.col+t.val.Length);
break;
}
case 25: {
CallProc(out stmt);
stmt.AddSequencePoint(sl,sc, t.line,t.col+t.val.Length);
break;
}
case 6: {
Get();
bf = t;
StmtSeq(out stmtSeq);
Expect(9);
stmt = stmtSeq;
stmt.AddSequencePoint(bf);
stmt.AddSequencePoint(t);
break;
}
default: SynErr(52); break;
}
}
void WhileStmt(out Statement whileStmt)
{
Expression exp = null;
StatementSequence whileBranch = null;
Statement branchStmt = null;
whileStmt = null;
Expect(22);
int sl = t.line; int sc = t.col; Token tok = t;
Expr(out exp);
if (!ExpectBool(exp, tok, true)) { return; }
Expect(23);
int el = t.line; int ec = t.col+t.val.Length;
if (Options.BookVersion) {
Stmt(out branchStmt);
whileBranch = ToStatementSequence(branchStmt);
} else if (StartOf(1)) {
StmtSeq(out whileBranch);
Expect(24);
whileBranch.AddSequencePoint(t);
} else SynErr(54);
whileStmt = new While.AST.Statements.While((TypedExpression<bool>)exp, whileBranch);
whileStmt.AddSequencePoint(sl,sc,el,ec);
}
void ReadStmt(out Statement stmt)
{
stmt = null;
Expect(15);
if (la.kind == 1) {
Get();
stmt = new Read(new Variable(t.val));
} else if (la.kind == 6) {
Get();
Expect(1);
stmt = new Read(new Variable(t.val));
Expect(9);
} else SynErr(55);
}
void IfStmt(out Statement ifStmt)
{
StatementSequence ifBranch = null;
StatementSequence elseBranch = null;
Statement tmpStmt = null;
Expression exp = null;
ifStmt = null;
Expect(18);
int sl = t.line; int sc = t.col; Token tok = t;
Expr(out exp);
if (!ExpectBool(exp, tok, true)) {
return;
}
Expect(19);
int el = t.line; int ec = t.col+t.val.Length;
if (Options.BookVersion) {
Stmt(out tmpStmt);
ifBranch = ToStatementSequence(tmpStmt);
if (la.kind == 20) {
Get();
Stmt(out tmpStmt);
elseBranch = ToStatementSequence(tmpStmt);
}
} else if (StartOf(1)) {
StmtSeq(out ifBranch);
if (la.kind == 20) {
Get();
StmtSeq(out elseBranch);
}
Expect(21);
ifBranch.AddSequencePoint(t);
if (elseBranch != null) {
elseBranch.AddSequencePoint(t);
}
} else SynErr(53);
ifStmt = new If((TypedExpression<bool>)exp, ifBranch, elseBranch);
ifStmt.AddSequencePoint(sl,sc,el,ec);
}
void CallProc(out Statement callStmt)
{
Expression exp;
List<Expression> expressions = new List<Expression>();
Expect(25);
Token callToken = t;
Token exprToken = null;
Expect(1);
string proc = t.val;
Expect(6);
if (StartOf(2)) {
exprToken = la;
Expr(out exp);
expressions.Add(exp); ExpectIntArg(exp, exprToken);
while (la.kind == 12) {
Get();
exprToken = la;
Expr(out exp);
expressions.Add(exp); ExpectIntArg(exp, exprToken);
}
}
Expect(9);
callStmt = new Call(proc, expressions, callToken, exprToken);
}
void BlockStmt(out Statement block)
{
Expect(3);
if (Options.BookVersion) {
errors.SemErr(t.line, t.col, "Variable declarations are only allowed when using the /coursesyntax switch. Type 'wc.exe /help' for more information");
While.Environment.Exit(1);
}
VariableDeclarationSequence vars = new VariableDeclarationSequence();
SymbolTable.PushScope();
int sl = t.line;
int sc = t.col;
int el = t.line;
int ec = t.col+t.val.Length;
if (la.kind == 16) {
VarDecStmt(out vars);
}
StatementSequence statements;
StmtSeq(out statements);
Expect(4);
block = new Block(vars, statements);
block.AddSequencePoint(sl,sc,el,ec);
block.AddSequencePoint(t);
SymbolTable.PopScope();
}
void AssignStmt(out Statement assign)
{
Expression exp;
Variable var;
assign = null;
Expect(1);
var = new Variable(t.val);
if (!SymbolTable.IsInScope(t.val) && !Options.BookVersion) {
errors.SemErr(t.line, t.col, string.Format("Assignment to undeclared variable '{0}'",t.val));
}
Expect(17);
Token tok = t;
Expr(out exp);
if (!ExpectInt(exp, tok, true)) {
return;
}
assign = new Assign(var, (TypedExpression<int>)exp);
}