Curry III

Requirements

• Export curry as named and default. Accept a function and return a callable collector. Do not use fn.length to decide when to evaluate. Reject non-functions with TypeError.
• A call with one or more arguments returns a new collector containing all previously collected arguments followed by that group. A call with no arguments invokes fn with the collected arguments and returns its exact result. An empty call may therefore evaluate a variadic function with zero values.
• Explicit undefined counts as an argument. Never invoke fn on a nonempty call or while creating a collector. Use the this value of the empty terminating call.
• Every collector can be reused independently; evaluating it does not consume its arguments. Propagate synchronous errors and return promises unchanged. Rest/default parameters work. Placeholders, constructors, and automatic evaluation based on arity are excluded.
• The provided TypeScript overloads track termination and the result type; validating each collected argument’s type is outside scope.

Examples

Input: curry((...values) => values.reduce((sum,v)=>sum+v,0))(1,2)(3)()
Output: 6

Input: const prefix = curry((...xs)=>xs.join("-"))("a"); [prefix("b")(), prefix("c","d")()]
Output: ["a-b", "a-c-d"]