52 lines
1.4 KiB
JavaScript
52 lines
1.4 KiB
JavaScript
/**
|
|
* LogarithmPlotter - 2D plotter software to make BODE plots, sequences and distribution functions.
|
|
* Copyright (C) 2022 Ad5001
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <https://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
.pragma library
|
|
|
|
class InputExpression {
|
|
constructor(expression) {
|
|
this.position = 0;
|
|
this.input = expression;
|
|
}
|
|
|
|
next() {
|
|
return this.input[this.position++];
|
|
}
|
|
|
|
peek() {
|
|
return this.input[this.position];
|
|
}
|
|
|
|
skip(char) {
|
|
if(!atEnd() && peek() == char) {
|
|
this.position++;
|
|
} else {
|
|
this.raise("Unexpected character " + peek() + ". Expected character " + char);
|
|
}
|
|
}
|
|
|
|
atEnd() {
|
|
return this.position >= this.input.length;
|
|
}
|
|
|
|
raise(message) {
|
|
throw new SyntaxError(message + " at " + this.position + ".")
|
|
}
|
|
}
|
|
|