The Dictionary

In Smojo, all the words are stored in a dictionary, which is a hash. The keys of this dictionary are the names of the words in lower case and the values are the XTs. The following words can help you get and set this dictionary:

Words	Action
GET-DICTIONARY ( -- # )	Returns the entire dictionary as a hash and puts it on the stack.
SET-DICTIONARY ( # -- )	Replaces the current dictionary with the given hash.
MARK	Takes a snapshot of the dictionary. Since SET-DICTIONARY will cause an irreversible damage to the dictionary if you use the wrong hash, it is a good practice to use MARK before that.
RESTORE	Restores the dictionary back to the version previously MARK ed.

Here are some examples of using these words.

Get the dictionary

For example,

DUP

is a word. If "dup" is on the stack as a string, we can use

GET-DICTIONARY

to retrieve the XT of

DUP

		"dup" get-dictionary #@ .
		com.terraweather.mini.XT@1969ea60 ok

Be reminded that the returned XT will be different when you try the example above

Set the dictionary

For example, if "plus" is on the stack as a string and we want to create a word

PLUS

which functions as the word

, we can use

SET-DICTIONARY

to do so:

		"plus" ' + get-dictionary >R
		ok
		R@ #! \ add "plus" and XT of + key-value pair into the dictionary hash
		ok
		R> set-dictionary
		ok
		3 5 plus .
		8 ok

Quiz

Question 1

In the example of

SET-DICTIONARY

, try to use

MARK

and

RESTORE

to restore the dictionary back to the original version at the end of the program.

		"plus" ' + get-dictionary >R
		mark
		R@ #!
		R> set-dictionary
		restore

Question 2

Write a word

BIND ( "name" xt -- )

which binds the given name and XT and add it to the dictionary.

		: BIND ( "name" xt -- )
			get-dictionary >R
			R@ #!
			R> set-dictionary 
		;

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