private void EmitIfStatement(Statement.If ifStmt, BlockCollector blockCollector)
{
var ifStmtElseIfs = (IAstList <ElseIf>)ifStmt.ElseIfs;
var elseBody = ifStmt.Else.HasValue ? EmitStatement(ifStmt.Else.Value.Body).ToBlockExpression() : null;
Expression elseIfExpr = null;
// else if statements
if (ifStmt.ElseIfs != null && ifStmtElseIfs.Count > 0)
{
var lastElseIf = ifStmtElseIfs[ifStmtElseIfs.Count - 1];
Expression lastElseIfExpr = elseBody == null
? Expression.IfThen(EmitExpression(lastElseIf.Condition), EmitStatement(lastElseIf.Body).ToBlockExpression())
: Expression.IfThenElse(EmitExpression(lastElseIf.Condition), EmitStatement(lastElseIf.Body).ToBlockExpression(), elseBody);
for (int i = ifStmtElseIfs.Count - 2; i >= 0; i--)
{
var currentElseIf = ifStmtElseIfs[i];
elseIfExpr = Expression.IfThenElse(
EmitExpression(currentElseIf.Condition), EmitStatement(currentElseIf.Body).ToBlockExpression(),
Expression.Block(lastElseIfExpr));
lastElseIfExpr = elseIfExpr;
}
elseBody = Expression.Block(elseIfExpr ?? lastElseIfExpr);
}
blockCollector.AddExpression(elseBody == null
? Expression.IfThen(EmitExpression(ifStmt.Condition), EmitStatement(ifStmt.Body).ToBlockExpression())
: Expression.IfThenElse(EmitExpression(ifStmt.Condition), EmitStatement(ifStmt.Body).ToBlockExpression(), elseBody));
}
public object VisitIfStatement(Statement.If statement)
{
Resolve(statement.condition);
Resolve(statement.thenBranch);
if (statement.elseBranch != null)
{
Resolve(statement.elseBranch);
}
return(null);
}
public object VisitIfStatement(Statement.If statement)
{
if (IsTruthy(Evaluate(statement.condition)))
{
Execute(statement.thenBranch);
}
else if (statement.elseBranch != null)
{
Execute(statement.elseBranch);
}
return(null);
}
public override Statement VisitSTMR_If([NotNull] S_ScriptParser.STMR_IfContext context)
{
Statement.If x = new Statement.If(this._Host, this._Master, context.K_ELSE() != null);
foreach (S_ScriptParser.StatementContext s in context.statement())
{
x.AddChild(this.Visit(s));
}
foreach (S_ScriptParser.ExpressionContext e in context.expression())
{
x.Parameters.Add("F" + x.Parameters.Count.ToString(), this._expr.Render(e));
}
this._Master = x;
return(x);
}
Expr IStatementVisitor <Expr> .Visit(Statement.If statement)
{
var testExpr = statement.Test.Visit(this);
var bodyExpr = Visit(statement.Body);
var elseExpr = statement.ElseBody != null?Visit(statement.ElseBody) : Expr.Default(typeof(void));
var elseifExprs = statement.Elseifs.Aggregate(elseExpr, ElseifCombiner);
return
(Expr.IfThenElse(
Expr.Dynamic(
Context.DynamicCache.GetConvertBinder(typeof(bool)),
typeof(bool),
testExpr),
bodyExpr,
elseifExprs));
}
public object VisitIfStatement(Statement.If stmt)
{
// TODO fix returningBranch spaget
returningBranch = false;
stmt.Then.Accept(this);
var thenReturning = returningBranch;
returningBranch = false;
if (stmt.Else != null)
{
stmt.Else.Accept(this);
}
stmt.Returning = thenReturning && returningBranch;
return(null);
}
public ByteCodeChunk VisitIf(Statement.If statement)
{
var chunk = new ByteCodeChunk();
chunk.AddRange(VisitExpression(statement.Condition));
var thenBlock = VisitBlock(statement.ThenBlock);
chunk.AddInstruction(Instruction.JmpIfZero, thenBlock.Count);
chunk.AddRange(thenBlock);
if (statement.ElseBlock == null)
{
return(chunk);
}
var elseBlock = VisitBlock(statement.ElseBlock);
chunk.AddInstruction(Instruction.JmpShort, elseBlock.Count);
chunk.AddRange(elseBlock);
return(chunk);
}
public object VisitIfStatement(Statement.If stmt)
{
stmt.Condition.Accept(this);
addInstruction(0x04); // if
addInstruction(0x40); // if returns void
stmt.Then.Accept(this);
if (stmt.Else != null)
{
addInstruction(0x05);
stmt.Else.Accept(this);
}
addInstruction(0x0b); // end
// Add a dummy return value if all branches of if return a value
// This return value will never be reached, but wasm doesn't know it
if (stmt.Returning)
{
addInstruction(ZERO);
}
return(null);
}
