Notes on the Postfix Notation.
In Postfix calculators, the operators follow their operands, no equals key is required to force computation to occur and there are no requirement for the precedence rules required in infix notation. Brackets and parentheses are unnecessary: the user merely performs calculations in the order that is required, letting the automatic stack store intermediate results on the fly for later use.
| prefix notation | infix notation | postfix notation |
|---|---|---|
+ 1 * 2 3 |
1 + (2 * 3) |
1 2 3 * + |
For instance, one would write 3 4 + rather than 3 + 4. If there are multiple operations, operators are given immediately after their second operands. The expression written (5 + 10) * 3 in conventional notation would be written 10 5 + 3 * in reverse Polish notation.
| operation | 3 | 10 | 5 | + | * |
|---|---|---|---|---|---|
| stack | 3 | 10 | 5 | 15 | 45 |
| 3 | 10 | 3 | |||
| 3 |
The automatic stack permits the automatic storage of intermediate results for use later: this key feature is what permits Postfix calculators to easily evaluate expressions of arbitrary complexity: they do not have limits on the complexity of expression they can evaluate.
incoming: firth cccc solresol basic concatenative postscript modal lisp uxntal