Compilers: Principles and Practice by Pearson

346 Compilers – Principles and Practice

c

Forth definitions can be implemented in Forth – called high-level definitions – or in some other

way, usually a lower-level language and as a result often called low-level definitions, code

definitions or primitives.

c

Many Forth systems are implemented mainly in Forth.

If you want to learn and use FORTH in some application, you should start by getting familiar with

the following words in FORTH:

Arithmetic: + − * / /MOD */ ABS INVERT

Comparison: MIN MAX =

Logic: AND OR XOR NOT

Stack manipulation: DUP DROP SWAP OVER

Loops and decisions: IF ELSE ENDIF ?DO I LOOP

Input/Output: . ." EMIT CR KEY

Defining words: ...