memesql2

These Python scripts receive Memelang queries, convert them to SQL, then execute them on a Postgres database.

• Demo: https://demo.memelang.net/
• Contact: [email protected]
• License: Copyright HOLTWORK LLC. Patent pending.

Files

• cache.py cache common terms in program memory
• conf.py database configurations
• core.meme core memelang terms and IDs
• db.py database configuration and library for CLI usage
• main.py CLI interface for queries and testing
• memelang.py library to parse Memelang commands into SQL
• memeterm.py library to convert string terms to integer IDs
• presidents.meme example terms and relations for the U.S. presidents

Installation

Installation on Ubuntu:

# Install packages
sudo apt install -y git postgresql python3 python3-psycopg2
systemctl start postgresql
systemctl enable postgresql

# Download files
git clone https://github.com/memelang-net/memesql2.git memesql
cd memesql

# Configure the db.py file according for your Postgres settings
# Create postgres DB and user from the CLI
sudo python3 ./main.py dbadd

# Create meme and term tables in the DB
sudo python3 ./main.py tableadd

# Load core terms
python3 ./main.py file ./core.meme

# Load example presidents data (optional)
python3 ./main.py file ./presidents.meme

Example CLI Usage

Execute a query:

# python3 ./main.py get "john_adams.spouse"

Outputs:

SQL: SELECT * FROM meme m0 WHERE m0.aid='john_adams' AND m0.rid='spouse' AND m0.qnt!=0

+---------------------+---------------------+---------------------+------------+
| A                   | R                   | B                   |          Q |
+---------------------+---------------------+---------------------+------------+
| john_adams          | spouse              | abigail_adams       |          1 |
+---------------------+---------------------+---------------------+------------+

Variable Naming Conventions

• sql is an SQL query string
• mqry is a Memelang string
• mexp is a meme expression comprising [operator, operand]
• mstate is a meme statement comprising a list of meme expressions (above)
• mcmd is list of meme statements (above)
• marr is list of meme commands (above)
• meme is a list in the form of [A, R, B, Q] typically a database row from the meme table
• memes is a list of [A, R, B, Q]
• trms is a list of terms such as ['Alice', 'Bob'] typically strings but may also contain integers

Library Functions

The library functions are in the memelang.py script.

• memelang.mqry2sql() receives a Memelang string like john_adams.spouse and returns an SQL query string.

• memelang.mqry2marr() receives a Memelang string and returns a parsed array called marr.

• memelang.marr2mqry() receives marr and returns a Memelang string.

• memelang.marr2sql() receives marr and returns an SQL query string.

• memelang.meme2mqry() receives database results in the form of an array of [A, R, B, Q] tuples and returns a Memelang string.