prosper/words.go

package main

import "fmt"

// ErrNoWordFound flags if the requested word is not in the dictionary
var ErrNoWordFound = fmt.Errorf("no word found")

// Dictionary is a simple map of names to words
type Dictionary map[string]Word

// A Word defines a subroutine
type Word struct {
	Name        string             // Name of our word/variable
	Impl        func(string) error // built-in implementation of the word
	Source      []string           // source, if user-defined
	Variable    int                // if this is a variable, the memory address
	Immediate   bool               // is this word immediate?
	BranchCheck bool               // is this word part of IF/ELSE/THEN?
}

// AddWord inserts a new word into the dictonary, overwriting any existing word by that name
func (d Dictionary) AddWord(name string, w Word) {
	d[name] = w
}

// GetWord returns a word from the dictionary or an error if it's undefined
func (d Dictionary) GetWord(name string) (Word, error) {
	w, ok := d[name]
	if !ok {
		return Word{
			Name: name,
		}, ErrNoWordFound
	}
	return w, nil
}