public Operation readBlock(TokenList tokens) {
Operation operation = new Operation(OP_BLOCK);
Token token;
if (!tokens.hasNext()) {
// report error
return null;
}
token = tokens.next();
if (token.getType() != TT_CBRACEL) {
// report error
return null;
}
OperatorReader opReader = new OperatorReader();
while (true) {
Operation operator = opReader.readOperator(tokens);
if (operator == null) {
break;
}
operation.addOperand(operator);
}
// ??? check TT_CBRACER
return operation;
}
private Operation readFunctionType(TokenList tokens) {
Token token;
Operation operation = new Operation(OP_TYPE);
if (!tokens.hasNext()) {
// report error;
return null;
}
token = tokens.next();
if (token.getType() != TT_RESERVED) {
// report error
return null;
}
operation.setValue(token.getValue());
if (!tokens.hasNext()) {
return operation;
}
token = tokens.next();
if (token.getType() == TT_STAR) {
// wrap simple type with type-ptr operation
Operation tmp = operation;
operation = new Operation(OP_TYPEPTR);
operation.addOperand(tmp);
} else {
tokens.back();
}
return operation;
}
public Operation readFunctionDefinition(TokenList tokens) {
Operation operation = new Operation(OP_FUNCDEF);
Operation op;
op = readFunctionType(tokens);
if (op == null) {
return null;
}
operation.addOperand(op);
op = readFunctionName(tokens);
if (op == null) {
return null;
}
operation.addOperand(op);
op = readFunctionParameters(tokens);
if (op == null) {
return null;
}
operation.addOperand(op);
op = readFunctionBody(tokens);
if (op == null) {
return null;
}
operation.addOperand(op);
return operation;
}
private Operation readFunctionName(TokenList tokens) {
Operation operation = new Operation(OP_VAR);
Token token;
if (!tokens.hasNext()) {
// report error
return null;
}
token = tokens.next();
if (token.getType() != TT_IDENTIFIER) {
// report error
return null;
}
operation.setValue(token.getValue());
return operation;
}
private Operation readFunctionParameters(TokenList tokens) {
Operation operation = new Operation(OP_FUNCPARAMS);
Token token;
if (!tokens.hasNext()) {
// report error, "(" expected
return null;
}
token = tokens.next();
if (token.getType() != TT_RBRACEL) {
// report error, "(" expected
return null;
}
if (!tokens.hasNext()) {
// report error
return null;
}
token = tokens.next();
if (token.getType() == TT_RBRACER) {
// empty params list
return operation;
}
Operation params = new Operation(OP_FUNCPARAMS);
while (true) {
Operation param = new Operation(OP_FUNCPARAM);
Operation type = new Operation(OP_TYPE);
Operation identifier = new Operation(OP_VAR);
if (token.getType() != TT_IDENTIFIER) {
// report error
return null;
}
type.setValue(token.getValue());
if (!tokens.hasNext()) {
// report error
return null;
}
token = tokens.next();
if (token.getType() == TT_STAR) {
Operation ptr = new Operation();
ptr.addOperand(type);
type = ptr;
if (!tokens.hasNext()) {
// report error
return null;
}
token = tokens.next();
}
param.addOperand(type);
if (token.getType() != TT_IDENTIFIER) {
// report error
return null;
}
identifier.setValue(token.getValue());
param.addOperand(identifier);
params.addOperand(param);
if (!tokens.hasNext()) {
// report error
return null;
}
token = tokens.next();
if (token.getType() == TT_RBRACER) {
break; // end of parameter definition
}
if (token.getType() != TT_COMMA) {
// report error
return null;
}
if (!tokens.hasNext()) {
// report error
return null;
}
token = tokens.next();
}
operation.addOperand(params);
return operation;
}