dhermes

import graphql.language
import networkx as nx
import tabulate


def _find_field_fragment_dependencies(
    field_node: graphql.language.ast.FieldNode,
) -> list[str]:
    if field_node.selection_set is None:
        return []

dhermes

Subtleties of Go JSON marshaling and null / nil

The TL;DR here is that if the standard encoding/json machinery in Go sees a null in a JSON field or a nil pointer in a Go field (of type *T), then it will not invoke the UnmarshalJSON() / MarshalJSON() on your type.

$ go run ./main.go
t1 = main.T{Shift:(*main.Point)(nil)} (nil stays nil, UnmarshalJSON() not invoked)

dhermes

# Copyright (c) 2023 - Present. Hardfin, Inc. All rights reserved.
# Hardfin Confidential - Restricted

import csv
import io
import pathlib
import subprocess
import tempfile

dhermes

The problem with "as-of-now" computed columns

The below illustrates why only actually IMMUTABLE functions should be used for PostgreSQL generated columns.

Basic status

Using a function that incorporates the current time, we can generate a status based on the value of a given timestamp:

dhermes

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How many nan values exist?

It turns out a lot (2**52). Anything where the 12 exponent bits are all 1, independent of the values of the other 52 bits).

$ python main.py
binary(1.0)  = 0011111111110000000000000000000000000000000000000000000000000000
binary(2.0)  = 0100000000000000000000000000000000000000000000000000000000000000
binary(-1.0) = 1011111111110000000000000000000000000000000000000000000000000000

dhermes

package main

import (
	"fmt"
	"os"

	"github.com/google/uuid"
)

type mapKey struct {

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/__pycache__/
/supervisord.log
/supervisord.pid

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WITH raw_relation_sizes AS (
  SELECT
    n.nspname || '.' || c.relname as table_name,
    pg_relation_size(n.nspname || '.' || c.relname) AS relation_size
  FROM
    pg_catalog.pg_class AS c
  LEFT OUTER JOIN
    pg_catalog.pg_namespace AS n
  ON
    n.oid = c.relnamespace

dhermes

package main

import (
	"fmt"
)

type Interface interface {
	Foo() int
	Bar() string
}