ASTIndexHelper.java 文件源码

public static CreateIndexDesc walk(EsperEPL2GrammarParser.CreateIndexExprContext ctx, Map<Tree, ExprNode> astExprNodeMap) {
    String indexName = ctx.n.getText();
    String windowName = ctx.w.getText();

    boolean unique = false;
    if (ctx.u != null) {
        String ident = ctx.u.getText();
        if (ident.toLowerCase(Locale.ENGLISH).trim().equals("unique")) {
            unique = true;
        } else {
            throw ASTWalkException.from("Invalid keyword '" + ident + "' in create-index encountered, expected 'unique'");
        }
    }

    List<CreateIndexItem> columns = new ArrayList<>();
    List<EsperEPL2GrammarParser.CreateIndexColumnContext> cols = ctx.createIndexColumnList().createIndexColumn();
    for (EsperEPL2GrammarParser.CreateIndexColumnContext col : cols) {
        CreateIndexItem item = walk(col, astExprNodeMap);
        columns.add(item);
    }
    return new CreateIndexDesc(unique, indexName, windowName, columns);
}