// A map literal.
private static void Map(Compiler c, bool allowAssignment)
{
// Load the Map class.
int mapClassSymbol = c._parser.Module.Variables.FindIndex(v => v.Name == "Map");
c.EmitShortArg(Instruction.LoadModuleVar, mapClassSymbol);
// Instantiate a new map.
c.CallMethod(0, "<instantiate>");
// Compile the map elements. Each one is compiled to just invoke the
// subscript setter on the map.
if (c.Peek() != TokenType.RightBrace)
{
do
{
c.IgnoreNewlines();
// Push a copy of the map since the subscript call will consume it.
c.Emit(Instruction.Dup);
// The key.
c.ParsePrecedence(false, Precedence.Primary);
c.Consume(TokenType.Colon, "Expect ':' after map key.");
// The value.
c.Expression();
c.CallMethod(2, "[_]=(_)");
// Discard the result of the setter call.
c.Emit(Instruction.Pop);
} while (c.Match(TokenType.Comma));
}
// Allow newlines before the closing '}'.
c.IgnoreNewlines();
c.Consume(TokenType.RightBrace, "Expect '}' after map entries.");
}
private static void InfixOp(Compiler c, bool allowAssignment)
{
GrammarRule rule = c.GetRule(c._parser.Previous.Type);
// An infix operator cannot end an expression.
c.IgnoreNewlines();
// Compile the right-hand side.
c.ParsePrecedence(false, rule.Precedence + 1);
// Call the operator method on the left-hand side.
Signature signature = new Signature { Type = SignatureType.Method, Arity = 1, Name = rule.Name, Length = rule.Name.Length };
c.CallSignature(Instruction.Call0, signature);
}
private static void and_(Compiler c, bool allowAssignment)
{
c.IgnoreNewlines();
// Skip the right argument if the left is false.
int jump = c.EmitJump(Instruction.And);
c.ParsePrecedence(false, Precedence.LogicalAnd);
c.PatchJump(jump);
}
private static void Conditional(Compiler c, bool allowAssignment)
{
// Ignore newline after '?'.
c.IgnoreNewlines();
// Jump to the else branch if the condition is false.
int ifJump = c.EmitJump(Instruction.JumpIf);
// Compile the then branch.
c.ParsePrecedence(allowAssignment, Precedence.Ternary);
c.Consume(TokenType.Colon, "Expect ':' after then branch of conditional operator.");
c.IgnoreNewlines();
// Jump over the else branch when the if branch is taken.
int elseJump = c.EmitJump(Instruction.Jump);
// Compile the else branch.
c.PatchJump(ifJump);
c.ParsePrecedence(allowAssignment, Precedence.Assignment);
// Patch the jump over the else.
c.PatchJump(elseJump);
}
// Unary operators like `-foo`.
private static void UnaryOp(Compiler c, bool allowAssignment)
{
GrammarRule rule = c.GetRule(c._parser.Previous.Type);
c.IgnoreNewlines();
// Compile the argument.
c.ParsePrecedence(false, Precedence.Unary + 1);
// Call the operator method on the left-hand side.
c.CallMethod(0, rule.Name);
}