This page is about operator precedence parsing. Some background notes are here.
Operators are + - * / = % (mod) and ^ exponentiation. Variable names are lower case a to z. Brackets are ( ) round.
Valid expression examples are 3+4 7*(4+3) 12.2-5.6 x=9 y=2*x+1
In this panel the user can input a single expression, tokenise it, then evaluate it seeing the stacks one step at a time.
The table below shows stacks before the step, and the token being processed. 'Action' describes what happens. Resulting stacks are shown in the next line.
|Step||Operator stack||Value stack||Token||Action|
In this panel the user can enter a script of expressions, one per line, then evaluate these, and see the symbol table after execution. This is about expressions which use assignments to variables.Enter script: