Forth in Crystal
Implement an evaluator for a very simple subset of Forth
exercism fetch crystal forth
Implement an evaluator for a very simple subset of Forth.
Forth is a stack-based programming language. Implement a very basic evaluator for a small subset of Forth.
Your evaluator has to support the following words:
Your evaluator also has to support defining new words using the
: word-name definition ;.
To keep things simple the only data type you need to support is signed integers of at least 16 bits size.
You should use the following rules for the syntax: a number is a sequence of one or more (ASCII) digits, a word is a sequence of one or more letters, digits, symbols or punctuation that is not a number. (Forth probably uses slightly different rules, but this is close enough.)
Words are case-insensitive.
Follow the setup instructions for Crystal here:
More help installing can be found here:
Making the Test Suit Pass
Execute the tests with:
$ crystal spec
In each test suite all but the first test have been skipped.
Once you get a test passing, you can unskip the next one by changing
Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.