/* -*- tab-width: 4 -*-
*
* Electric(tm) VLSI Design System
*
* File: EvalSpice.java
*
* Copyright (c) 2005 Sun Microsystems and Static Free Software
*
* Electric(tm) 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.
*
* Electric(tm) 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 Electric(tm); see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, Mass 02111-1307, USA.
*/
package com.sun.electric.database.variable;
import com.sun.electric.database.text.TextUtils;
import java.io.IOException;
import java.io.StreamTokenizer;
import java.io.StringReader;
/**
* Class to evaluate Spice expressions.
* User: gainsley
* Date: Aug 17, 2006
*/
public class EvalSpice {
private String expr;
private StreamTokenizer tokenizer;
int openParens;
public EvalSpice(String expr) {
this.expr = expr;
openParens = 0;
}
public Object evaluate() {
if (expr == null) {
return null;
}
StringReader reader = new StringReader(expr);
tokenizer = new StreamTokenizer(reader);
tokenizer.parseNumbers();
tokenizer.ordinaryChar('(');
tokenizer.ordinaryChar(')');
tokenizer.ordinaryChar('*');
tokenizer.ordinaryChar('/');
tokenizer.ordinaryChar('+');
tokenizer.ordinaryChar('-');
tokenizer.ordinaryChar('<');
tokenizer.ordinaryChar('=');
tokenizer.ordinaryChar('>');
tokenizer.ordinaryChar('!');
tokenizer.ordinaryChar('?');
tokenizer.ordinaryChar(':');
tokenizer.wordChars('_', '_');
try {
return evalEq().eval();
} catch (IOException e) {
System.out.println(e.getMessage());
} catch (ParseException e) {
String parsed = "";
try {
long left = reader.skip(Long.MAX_VALUE);
parsed = expr.substring(0, expr.length() - (int) left);
} catch (IOException e2) {
}
if (!parsed.equals("")) {
parsed = ": " + parsed + " <--";
}
System.out.println("Spice Parse Error: " + e.getMessage() + parsed + " " + tokenizer.toString());
System.out.println(" Original string: " + expr);
}
return expr;
}
/**
* Evaluate an expression
* @return the evaluated expression
* @throws IOException
* @throws ParseException
*/
private SimpleEq evalEq() throws IOException, ParseException {
SimpleEq eq = new SimpleEq();
while (true) {
int tt = tokenizer.nextToken();
if (tt == StreamTokenizer.TT_EOF || tt == StreamTokenizer.TT_EOL) {
if (openParens > 0) {
throw new ParseException("Unmatched open parens");
}
return eq;
} // delimiters come first
else if (tt == ')') { // end eq
openParens--;
if (openParens < 0) {
throw new ParseException("Unmatched close parens");
}
Object value = eq.eval();
if (value instanceof String) {
return new SimpleEq("(" + value.toString() + ")", null, null);
}
return new SimpleEq(value, null, null);
} else if (tt == '(') { // begin new eq
openParens++;
if (!eq.addIdentifierOk()) {
throw new ParseException("Too many identifiers");
}
Object id = evalEq();
eq.addIdentifier(id);
} else if (tt == ',') { // end eq
return eq;
} else if (tt == StreamTokenizer.TT_NUMBER) {
tokenizer.pushBack();
eq.addIdentifier(parseNumber());
} else if (tt == StreamTokenizer.TT_WORD) {
if (tokenizer.sval.equalsIgnoreCase("sin")) {
expect('(');
openParens++;
Object arg = evalEq().eval();
if (arg instanceof Double) {
arg = new Double(Math.sin(((Double) arg).doubleValue()));
} else {
arg = "sin" + format(arg);
}
eq.addIdentifier(arg);
} else if (tokenizer.sval.equalsIgnoreCase("min")) {
expect('(');
openParens++;
Object m1 = evalEq().eval();
Object m2 = evalEq().eval();
if ((m1 instanceof Double) && (m2 instanceof Double)) {
double a = ((Double) m1).doubleValue();
double b = ((Double) m2).doubleValue();
m1 = new Double(Math.min(a, b));
} else {
String m2str = format(m2);
// remove extraneous ()'s
if (m2str.startsWith("(") && m2str.endsWith(")")) {
m2str = m2str.substring(1, m2str.length() - 1);
}
m1 = "min(" + format(m1) + "," + m2str + ")";
}
eq.addIdentifier(m1);
} else if (tokenizer.sval.equalsIgnoreCase("max")) {
expect('(');
openParens++;
Object m1 = evalEq().eval();
Object m2 = evalEq().eval();
if ((m1 instanceof Double) && (m2 instanceof Double)) {
double a = ((Double) m1).doubleValue();
double b = ((Double) m2).doubleValue();
m1 = new Double(Math.max(a, b));
} else {
String m2str = format(m2);
// remove extraneous ()'s
if (m2str.startsWith("(") && m2str.endsWith(")")) {
m2str = m2str.substring(1, m2str.length() - 1);
}
m1 = "max(" + format(m1) + "," + m2str + ")";
}
eq.addIdentifier(m1);
} else if (tokenizer.sval.equalsIgnoreCase("abs")) {
expect('(');
openParens++;
Object arg = evalEq().eval();
if (arg instanceof Double) {
arg = new Double(Math.abs(((Double) arg).doubleValue()));
} else {
arg = "abs" + format(arg);
}
eq.addIdentifier(arg);
} else if (tokenizer.sval.equalsIgnoreCase("sqrt")) {
expect('(');
openParens++;
Object arg = evalEq().eval();
if (arg instanceof Double) {
arg = new Double(Math.sqrt(((Double) arg).doubleValue()));
} else {
arg = "sqrt" + format(arg);
}
eq.addIdentifier(arg);
} else if (tokenizer.sval.equalsIgnoreCase("int")) {
expect('(');
openParens++;
Object arg = evalEq().eval();
if (arg instanceof Double) {
arg = new Double((int) (((Double) arg).doubleValue()));
} else {
arg = "int" + format(arg);
}
eq.addIdentifier(arg);
} else {
// identifier
eq.addIdentifier(tokenizer.sval);
}
} else if (tt == '*') {
eq.addOp(Op.MULT);
} else if (tt == '/') {
eq.addOp(Op.DIV);
} else if (tt == '+') {
eq.addOp(Op.PLUS);
} else if (tt == '-') {
eq.addOp(Op.MINUS);
} else if (tt == '<') {
tt = tokenizer.nextToken();
if (tt == '=') {
eq.addOp(Op.LTOE);
} else {
tokenizer.pushBack();
eq.addOp(Op.LT);
}
} else if (tt == '>') {
tt = tokenizer.nextToken();
if (tt == '=') {
eq.addOp(Op.GTOE);
} else {
tokenizer.pushBack();
eq.addOp(Op.GT);
}
} else if (tt == '=') {
expect('=');
eq.addOp(Op.EQ);
} else if (tt == '!') {
expect('=');
eq.addOp(Op.NE);
} else if (tt == '?') {
eq.addOp(Op.COND);
/*
Object arg1 = evalEq().eval();
if (tokenizer.ttype != ':') throw new ParseException("Expected ':' after conditional");
Object arg2 = evalEq().eval();
SimpleEq condval = new SimpleEq(arg1, Op.CONDCHOICE, arg2);
eq.addIdentifier(condval);
*/
} else if (tt == ':') { // end conditional true arg
eq.addOp(Op.CONDCHOICE);
}
}
}
/**
* Parse a number. A number may have the format:
* <P>
* number[g|meg|k|m|u|n|p|f]
* <p>
* number(e)[-]number
* @return
* @throws IOException
* @throws ParseException
*/
private Object parseNumber() throws IOException, ParseException {
int tt = tokenizer.nextToken();
if (tt == StreamTokenizer.TT_NUMBER) {
double val = tokenizer.nval;
// peek ahead to check if exponential, or multiplier
tokenizer.ordinaryChar('e');
tokenizer.ordinaryChar('E');
tt = tokenizer.nextToken();
if (tt == 'e' || tt == 'E') {
tt = tokenizer.nextToken();
boolean minus = false;
if (tt == '-') {
minus = true;
tt = tokenizer.nextToken();
}
if (tt == StreamTokenizer.TT_NUMBER) {
double exp = tokenizer.nval;
if (minus) {
exp = -1.0 * exp;
}
val = val * Math.pow(10, exp);
} else {
throw new ParseException("Invalid token");
}
} else if (tt == StreamTokenizer.TT_WORD) {
if (tokenizer.sval.equalsIgnoreCase("g")) {
val = val * 1e9;
} else if (tokenizer.sval.equalsIgnoreCase("meg")) {
val = val * 1e6;
} else if (tokenizer.sval.equalsIgnoreCase("k")) {
val = val * 1e3;
} else if (tokenizer.sval.equalsIgnoreCase("m")) {
val = val * 1e-3;
} else if (tokenizer.sval.equalsIgnoreCase("u")) {
val = val * 1e-6;
} else if (tokenizer.sval.equalsIgnoreCase("n")) {
val = val * 1e-9;
} else if (tokenizer.sval.equalsIgnoreCase("p")) {
val = val * 1e-12;
} else if (tokenizer.sval.equalsIgnoreCase("f")) {
val = val * 1e-15;
} else {
throw new ParseException("Invalid token");
}
} else {
tokenizer.pushBack();
}
tokenizer.wordChars('e', 'e');
tokenizer.wordChars('E', 'E');
return new Double(val);
}
throw new ParseException("Expected number");
}
private void expect(int token) throws IOException, ParseException {
int tt = tokenizer.nextToken();
if (tt != token) {
throw new ParseException("Expected token " + token);
}
}
// ==================== Parsable Objects ========================
public static class ParseException extends Exception {
public ParseException(String msg) {
super(msg);
}
}
public static class Op {
public final String name;
public final int precedence;
private Op(String name, int precedence) {
this.name = name;
this.precedence = precedence;
}
public String toString() {
return name;
}
// operators with lower value precedence bind tighter than higher value precedence
public static final Op MULT = new Op("*", 2);
public static final Op DIV = new Op("/", 2);
public static final Op PLUS = new Op("+", 3);
public static final Op MINUS = new Op("-", 3);
public static final Op LT = new Op("<", 5);
public static final Op LTOE = new Op("<=", 5);
public static final Op GT = new Op(">", 5);
public static final Op GTOE = new Op(">=", 5);
public static final Op EQ = new Op("==", 6);
public static final Op NE = new Op("!=", 6);
public static final Op LAND = new Op("&&", 10);
public static final Op LOR = new Op("||", 11);
public static final Op CONDCHOICE = new Op(":", 12);
public static final Op COND = new Op("?", 13);
}
private static final Double ONE = new Double(1);
private static final Double ZERO = new Double(0);
/**
* A simple equation consists of two Identifiers (operands)
* that are Doubles, Strings, or other SimpleEq,
* and an operator *,/,+,-.
* <P>
* For a simple equation to be valid, it must define
* both operands and an operator. However, if the
* operator is '-', then the left hand operand may
* be null, to indicate a unary minus. Additionally,
* if only the left hand operator is defined, then it
* is simply one operand.
*/
public static class SimpleEq {
protected Object lhop; // left hand operand
private Op op; // operator
protected Object rhop; // right hand operand
boolean neglh = false;
boolean negrh = false;
public SimpleEq() {
this.lhop = null;
this.op = null;
this.rhop = null;
}
public SimpleEq(Object lhop, Op op, Object rhop) {
this.lhop = lhop;
this.op = op;
this.rhop = rhop;
}
public boolean addIdentifierOk() {
if (lhop == null) {
return true;
} else if (rhop == null && op != null) {
return true;
} else if (rhop instanceof SimpleEq) {
return ((SimpleEq) rhop).addIdentifierOk();
}
return false;
}
public void addIdentifier(Object id) throws ParseException {
if (lhop == null) {
lhop = id;
} else if (rhop == null && op != null) {
rhop = id;
} else if (rhop instanceof SimpleEq) {
((SimpleEq) rhop).addIdentifier(id);
} else {
throw new ParseException("Two operands with no operator");
}
}
public void addOp(Op operator) throws ParseException {
if (lhop == null && operator == Op.MINUS && !neglh) {
neglh = true; // unary minus on left hand operand
} else if (lhop == null) {
throw new ParseException("Operator " + operator + " with no left hand operand");
} // lhop defined from here on
else if (op == null && rhop == null) {
this.op = operator;
} else if (op != null && rhop == null && operator == Op.MINUS && !negrh) {
negrh = true; // unary minus on right hand operand
} else if (op != null && rhop != null) {
if (rhop instanceof SimpleEq) {
((SimpleEq) rhop).addOp(operator);
} else {
// operators with lower value precedence bind tighter than higher value precedence
if (operator.precedence < op.precedence) {
// bind right
rhop = new SimpleEq(rhop, operator, null);
// retain proper negation associations
((SimpleEq) rhop).neglh = negrh;
negrh = false;
} else {
// bind left
lhop = new SimpleEq(lhop, op, rhop);
this.op = operator;
this.rhop = null;
// retain proper negation associations
((SimpleEq) lhop).neglh = neglh;
((SimpleEq) lhop).negrh = negrh;
this.neglh = false;
this.negrh = false;
}
}
} else {
throw new ParseException(("Two operators in a row"));
}
}
/**
* Return either a Double, if the equation can be
* resolved numerically, or a String representing
* the equation after any numerical resolution can be done.
* @return a Double or a String
*/
public Object eval() throws ParseException {
if (lhop instanceof SimpleEq) {
lhop = ((SimpleEq) lhop).eval();
}
if (rhop instanceof SimpleEq) {
rhop = ((SimpleEq) rhop).eval();
}
if (op == Op.CONDCHOICE) {
return this;
}
if (op == Op.COND && (rhop instanceof SimpleEq)) {
SimpleEq condval = (SimpleEq) rhop;
if ((lhop instanceof Double) && (condval.lhop instanceof Double) && (condval.rhop instanceof Double)) {
double cond = ((Double) lhop).doubleValue();
if (neglh) {
cond = -1.0 * cond;
}
double valt = ((Double) condval.lhop).doubleValue();
if (condval.neglh) {
valt = -1.0 * valt;
}
double valf = ((Double) condval.rhop).doubleValue();
if (condval.negrh) {
valf = -1.0 * valf;
}
if (cond == 0) {
return valf;
}
return valt;
}
String neglhstr = condval.neglh ? "-" : "";
String negrhstr = condval.negrh ? "-" : "";
rhop = neglhstr + format(condval.lhop) + " : " + negrhstr + format(condval.rhop);
} else if ((lhop instanceof Double) && (rhop instanceof Double)) {
double lh = ((Double) lhop).doubleValue();
double rh = ((Double) rhop).doubleValue();
if (neglh) {
lh = -1.0 * lh;
}
if (negrh) {
rh = -1.0 * rh;
}
if (op == Op.MULT) {
return new Double(lh * rh);
} else if (op == Op.DIV) {
return new Double(lh / rh);
} else if (op == Op.PLUS) {
return new Double(lh + rh);
} else if (op == Op.MINUS) {
return new Double(lh - rh);
} else if (op == Op.LT) {
return lh < rh ? ONE : ZERO;
} else if (op == Op.LTOE) {
return lh <= rh ? ONE : ZERO;
} else if (op == Op.GT) {
return lh > rh ? ONE : ZERO;
} else if (op == Op.GTOE) {
return lh >= rh ? ONE : ZERO;
} else if (op == Op.EQ) {
return lh == rh ? ONE : ZERO;
} else if (op == Op.NE) {
return lh != rh ? ONE : ZERO;
} else if (op == Op.LAND) {
return (lh != 0 && rh != 0) ? ONE : ZERO;
} else if (op == Op.LOR) {
return (lh != 0 || rh != 0) ? ONE : ZERO;
}
} else if (op == null && rhop == null) {
if (neglh) {
if (lhop instanceof Double) {
return -1.0 * ((Double) lhop).doubleValue();
}
return "-" + lhop.toString();
}
return lhop;
}
// can't resolve numerically
String neglhstr = neglh ? "-" : "";
String negrhstr = negrh ? "-" : "";
String lhstr = (lhop == null ? "?" : format(lhop));
String rhstr = (rhop == null ? "?" : format(rhop));
return neglhstr + lhstr + " " + op + " " + negrhstr + rhstr;
}
}
private static String format(Object obj) {
// must be format double postfix, otherwise get 0 for numbers less than 0.001
if (obj instanceof Double) {
return TextUtils.formatDoublePostFix(((Double) obj).doubleValue());
}
return obj.toString();
}
// ================================ Main Test ================================
public static void main(String args[]) {
testEval("1 + 2", 3);
testEval("1 + 2 * 3", 7);
testEval("1 * 2 + 3", 5);
testEval("(1 + 2) * 3", 9);
testEval("(1 + 2) * x", "3 * x");
testEval("300 / -1.5e2", -2);
testEval("1.5e-2", 0.015);
testEval("20 * 1.5e-2", 0.3);
testEval("20 * 1.5m", 0.03);
testEval("(1 + a) * 3 + b", "(1 + a) * 3 + b");
testEval("1 + 2 * 3 + - 4", 3);
testEval("-1", -1);
testEval("-1 + 2 * 3 + - 4", 1);
testEval("-(1 + 2) * 3 + -4", -13);
testEval("-(1 + 2) * 3 + -4 * -2 - -4 * -3", -13);
testEval("-sin(3)", -Math.sin(3));
testEval("-sin(x)", "-sin(x)");
testEval("1-min(1,-2)", 3);
testEval("1-min(1,x)", null);
testEval("1-min((a+b)*c,x)", null);
testEval("1-min((a+b)*c,(a+b))", null);
testEval("-a + 2 * 3 * -b + - 4", null);
testEval("1 ? -2 : 4", -2);
testEval("0 ? -2 : 4", 4);
testEval("8 == 1 ? -2 : 4", 4);
testEval("8 > 1 ? -2 : 4", -2);
testEval("1 - 7 <= 1 ? -2 : 4", -2);
testEval("layer == 1 ? two + 1 : eight * 4 / 2", "layer == 1 ? two + 1 : eight * 4 / 2");
testEval("0 * 1 ? 3 / 2 : -4 + 10", 6);
testEval("(3==0?0.00441:3<8?0.011:0.016)*1e-15", 1.1e-17);
testEval("(layer==0?0.00441:layer<8?0.011:0.016)*1e-15", null);
System.out.println("\nThese should flag as errors:\n---------------------------\n");
testEval("1 2 +", null);
testEval("1 + * 2", null);
testEval("1 + 2 * - -3", null);
testEval("300 / -1.5ee2 + 5", null);
testEval("1-min((a+b)*c,(a+b)", null);
testEval("1/0", null);
testEval("M1 - M3 : 10001", null);
}
private static void testEval(String eq, String expected) {
EvalSpice sp = new EvalSpice(eq);
String evald = sp.evaluate().toString();
if (expected == null) {
System.out.println(eq + " = " + evald);
} else {
System.out.println(eq + " = " + evald + " -- (" + expected + ")");
assert (expected.equals(evald));
}
}
private static void testEval(String eq, double expected) {
EvalSpice sp = new EvalSpice(eq);
Object evald = sp.evaluate();
System.out.println(eq + " = " + evald + " -- (" + expected + ")");
assert (evald instanceof Double);
double val = ((Double) evald).doubleValue();
assert (val == expected);
}
}