harn-stdlib 0.8.90

// std/json — JSON utility patterns
//
// Import with: import "std/json"
pub import "std/json/stream"

/**
 * Pretty-print a value as indented JSON (2-space indent).
 * pretty.
 *
 * @effects: []
 * @allocation: heap
 * @errors: []
 * @api_stability: stable
 * @example: pretty(value)
 */
pub fn pretty(value) {
  return json_stringify_pretty(value)
}

/**
 * Safely parse JSON, returning nil on failure instead of throwing.
 * safe_parse.
 *
 * @effects: []
 * @allocation: heap
 * @errors: []
 * @api_stability: stable
 * @example: safe_parse(text)
 */
pub fn safe_parse(text) {
  let result = try {
    json_parse(text)
  }
  if is_ok(result) {
    return unwrap(result)
  }
  return nil
}

/**
 * Shallow-merge two dicts. Keys in `b` override matching keys in `a`.
 * Row-polymorphic: each argument carries its own row of fields, and the result
 * is the right-biased merge of both rows (`b`'s fields override `a`'s, every
 * field preserved with its real type). Merging two records with *different*
 * value types is therefore sound and precise — `merge({a: 1}, {b: "x"})`
 * returns `{a: int, b: string}` rather than collapsing to `dict`.
 *
 * @effects: []
 * @allocation: heap
 * @errors: []
 * @api_stability: stable
 * @example: merge(a, b)
 */
pub fn merge<R1, R2>(a: {...R1}, b: {...R2}) -> {...R1, ...R2} {
  return __dict_merge(a ?? {}, b ?? {})
}

/**
 * Pick the listed keys from `data`, dropping entries whose stored value is
 * `nil`. Generic over the value type — when called with a `dict<string, V>`
 * the projection keeps the same V.
 *
 * @effects: []
 * @allocation: heap
 * @errors: []
 * @api_stability: stable
 * @example: pick(data, keys)
 */
pub fn pick<V>(data: dict<string, V>, keys: list<string>) -> dict<string, V> {
  return __dict_pick(data ?? {}, keys ?? [])
}

/**
 * Drop the listed keys from `data`. Generic over the value type — the
 * resulting dict keeps the same value contract as the input.
 *
 * @effects: []
 * @allocation: heap
 * @errors: []
 * @api_stability: stable
 * @example: omit(data, keys)
 */
pub fn omit<V>(data: dict<string, V>, keys: list<string>) -> dict<string, V> {
  return __dict_omit(data ?? {}, keys ?? [])
}