// Package tokenize provides tooling to build a tokenizer in
// parser/combinator-style, used to feed data to the parser.
package tokenize

import (
	"fmt"
)

// Func is the function signature as returned by New: a function that takes
// any supported type of input, executes a tokenizer run and returns a
// Result struct (possibly nil) and an error (possibly nil).
type Func func(input interface{}) (*Result, error)

// New instantiates a new tokenizer.
//
// The tokenizer is a tokenizing state machine, in which tokenize.Handler
// functions are used to move the state machine forward during tokenizing.
// Using the New function, you can wrap a tokenize.Handler in a simple way,
// making it possible to feed some input to the handler and retrieve the
// tokenizing results.
//
// The startHandler argument points the tokenizer to the tokenize.Handler function
// that must be executed at the start of the tokenizing process. From there on
// other tokenize.Handler functions can be invoked recursively to implement the
// tokenizing process.
//
// This function returns a function that can be invoked to run the tokenizer
// against the provided input data. For an overview of allowed inputs, take a
// look at the documentation for parsekit.read.New().
func New(tokenHandler Handler) Func {
	return func(input interface{}) (*Result, error) {
		tokenAPI := NewAPI(input)
		ok := tokenHandler(tokenAPI)

		if !ok {
			err := fmt.Errorf("mismatch at %s", tokenAPI.Input.Cursor())
			return nil, err
		}

		tokenAPI.Result.Store()
		return &tokenAPI.Result, nil
	}
}