First step to extending this parser is cloning the repository `git clone git@github.com:hyrise/sql-parser.git` and making sure everything works by running the following steps:
```bash
make parser # builds the bison parser and flex lexer
make library # builds the libsqlparser.so
make test # runs the tests with the library
```
Rerun these steps whenever you change part of the parse. To execute the entire pipeline automatically you can run:
```bash
make cleanall # cleans the parser build and library build
make test # build parser, library and runs the tests
Create a new file and class in `src/sql/` or extend any of the existing Statements. Every statement needs to have the base class SQLStatement and needs to call its super constructor with its type. If you're defining a new statement type, you need to define a new StatementType in `SQLStatement.h`.
It is important that you create an appropriate constructor for your statement that zero-initializes all its pointer variables and that you create an appropriate destructor.
If you're extending an existing statement, skip to the non-terminal definition for that statement. I.e. for an InsertStatement the non-terminal insert_statement.
If you're defining a new statement, you will need to define your type in the \%union directive `hsql::ExampleStatement example_stmt`. Next you need to associate this type with a non-terminal `\%type <example_stmt> example_statement`. Then you have to define the non-terminal `example_statement`. Look the other non-terminals for statements to figure out how.