Function generateComprehensionIterator

src/ast/ast_generate.cpp:212–255

array comprehension generator( $() for ..... if where .... yield subexpr return false

    //              yield subexpr
    //      return false
    ExpressionPtr generateComprehensionIterator ( ExprArrayComprehension * expr ) {
        auto pClosure = new ExprBlock();
        pClosure->at = expr->subexpr->at;
        pClosure->returnType = new TypeDecl(Type::autoinfer);
        // yield subexpr
        auto pYield = new ExprYield(expr->at, expr->subexpr->clone());
        if ( !expr->subexpr->type->canCopy() ) {
            pYield->moveSemantics = true;
        }
        // for ...
        auto pForBlock = new ExprBlock();
        pForBlock->at = expr->at;
        pForBlock->inTheLoop = true;
        if ( expr->exprWhere ) {
            // yield block
            auto pPushBlock = new ExprBlock();
            pPushBlock->at = expr->at;
            pPushBlock->list.push_back(pYield);
            // for .... if where ... yield
            auto pIf = new ExprIfThenElse();
            pIf->at = expr->at;
            pIf->cond = expr->exprWhere->clone();
            pIf->if_true = pPushBlock;
            pForBlock->list.push_back(pIf);
        } else {
            // for .... yield
            pForBlock->list.push_back(pYield);
        }
        auto pFor = static_cast<ExprFor*>(expr->exprFor->clone());
        pFor->body = pForBlock;
        pClosure->list.push_back(pFor);
        // return false
        auto pRet = new ExprReturn();
        pRet->at = expr->at;
        pRet->subexpr = new ExprConstBool(expr->at, false);
        pClosure->list.push_back(pRet);
        // make block
        auto pMakeBlock = new ExprMakeBlock(expr->at,pClosure);
        // generator
        auto pMkGen = new ExprMakeGenerator(expr->at, pMakeBlock);
        pMkGen->iterType = new TypeDecl(*expr->subexpr->type);
        pMkGen->alwaysSafe = expr->alwaysSafe;
        return pMkGen;
    }

    /* a->b(args) is short for invoke(a.b, cast<auto> deref(a), args)  */
    ExprInvoke * makeInvokeMethod ( const LineInfo & at, Expression * a, const string & b ) {