Function toPat

src/compute-engine/rubi/compile.ts:76–104

* Convert a canonically boxed skeleton to matcher IR. `parentOp` / * `argIndex` give the canonical context that determines optional defaults.

(
  ce: ComputeEngine,
  expr: Expression,
  parentOp: string | null,
  _argIndex: number
)

  return expr;
}

/**
 * Convert a canonically boxed skeleton to matcher IR. `parentOp` /
 * `argIndex` give the canonical context that determines optional defaults.
 */
function toPat(
  ce: ComputeEngine,
  expr: Expression,
  parentOp: string | null,
  _argIndex: number
): Pat {
  if (expr.symbol) {
    if (expr.symbol === VAR) return { kind: 'var' };
    if (expr.symbol.startsWith(SLOT))
      return { kind: 'slot', name: expr.symbol.slice(SLOT.length) };
    if (expr.symbol.startsWith(OPT)) {
      const dflt = parentOp === 'Add' ? ce.Zero : ce.One;
      return {
        kind: 'optslot',
        name: expr.symbol.slice(OPT.length),
        default: dflt,
      };
    }
    return { kind: 'const', value: expr };
  }
  if (!expr.ops || expr.ops.length === 0 || !hasPlaceholder(expr))
    return { kind: 'const', value: expr };
  return {
    kind: 'node',
    op: expr.operator,
    ops: expr.ops.map((op, i) => toPat(ce, op, expr.operator, i)),
    ac: expr.operator === 'Add' || expr.operator === 'Multiply',