Flatten a Nested JSON Object

Problem Read a nested JSON object and flatten it into dot-notation key/value pairs, where each leaf's key is its full path from the root joined by dots.

Input / Output

• Input: a parsed JSON object containing arbitrarily nested sub-objects.
• Output: a flat map of dotted key → primitive value, with exactly one entry per leaf.

Constraints

• Nesting depth is arbitrary; only leaves (primitives) appear in the output.
• Settle the contract on the ambiguous cases first: how arrays are keyed (index-suffixed like a.0.b, or treated as opaque leaf values), what an empty object maps to (dropped, or a leaf with an empty value), and whether keys may themselves contain a literal dot — which makes the flattening lossy and non-invertible.
• Null values are leaves and must be preserved, not skipped.

Example Input:

a: {
  a1: 123,
  a2: {
    b: "abc",
    c: 32
  }
}

Output:

a.a1 = 123
a.a2.b = "abc"
a.a2.c = 32

• Note that a and a.a2 never appear as output keys in their own right — only leaves are emitted.