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Native function interface for the Truffle framework.
/*
* Copyright (c) 2017, 2021, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* The Universal Permissive License (UPL), Version 1.0
*
* Subject to the condition set forth below, permission is hereby granted to any
* person obtaining a copy of this software, associated documentation and/or
* data (collectively the "Software"), free of charge and under any and all
* copyright rights in the Software, and any and all patent rights owned or
* freely licensable by each licensor hereunder covering either (i) the
* unmodified Software as contributed to or provided by such licensor, or (ii)
* the Larger Works (as defined below), to deal in both
*
* (a) the Software, and
*
* (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
* one is included with the Software each a "Larger Work" to which the Software
* is contributed by such licensors),
*
* without restriction, including without limitation the rights to copy, create
* derivative works of, display, perform, and distribute the Software and make,
* use, sell, offer for sale, import, export, have made, and have sold the
* Software and the Larger Work(s), and to sublicense the foregoing rights on
* either these or other terms.
*
* This license is subject to the following condition:
*
* The above copyright notice and either this complete permission notice or at a
* minimum a reference to the UPL must be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package com.oracle.truffle.nfi;
final class Lexer {
public enum Token {
OPENPAREN("("),
CLOSEPAREN(")"),
OPENBRACKET("["),
CLOSEBRACKET("]"),
OPENBRACE("{"),
CLOSEBRACE("}"),
SEMICOLON(";"),
COLON(":"),
COMMA(","),
OR("|"),
ELLIPSIS("..."),
IDENTIFIER("identifier"),
STRING("string"),
INVALID(null),
EOF("EOF");
private final String name;
Token(String name) {
this.name = name;
}
public String getName() {
return name;
}
}
private final CharSequence source;
private int position;
private Token curToken;
private int curTokenStart;
private int curTokenEnd;
private Token nextToken;
private int nextTokenStart;
Lexer(CharSequence source) {
this.source = source;
this.position = 0;
lex();
}
public Token next() {
lex();
return curToken;
}
public Token peek() {
return nextToken;
}
public String currentValue() {
if (curTokenEnd > source.length()) {
return "";
} else {
int start = curTokenStart;
int end = curTokenEnd;
if (curToken == Token.STRING) {
// cut off string delimiters
start++;
end--;
}
return source.subSequence(start, end).toString();
}
}
public String peekValue() {
if (position > source.length()) {
return "";
} else {
return source.subSequence(nextTokenStart, position).toString();
}
}
public NFIParserException fail(String message) {
throw new NFIParserException(message, curToken == Token.EOF);
}
public NFIParserException fail(String message, Object... args) {
throw fail(String.format(message, args));
}
private boolean atEnd() {
return position >= source.length();
}
private char ch() {
if (atEnd()) {
return 0;
} else {
return source.charAt(position);
}
}
private void lex() {
curToken = nextToken;
curTokenStart = nextTokenStart;
curTokenEnd = position;
while (Character.isWhitespace(ch())) {
position++;
}
nextTokenStart = position;
nextToken = getNextToken();
}
private static boolean isIdentStartChar(char c) {
return Character.isAlphabetic(c) || c == '/' || c == '_';
}
private static boolean isIdentChar(char c) {
// @formatter:off
return Character.isAlphabetic(c)
|| Character.isDigit(c)
|| c == '/' || c == '.' // for filenames
|| c == '_';
// @formatter:on
}
private Token getNextToken() {
if (isIdentStartChar(ch())) {
do {
position++;
} while (isIdentChar(ch()));
return Token.IDENTIFIER;
} else {
char c = ch();
position++;
switch (c) {
case 0:
return Token.EOF;
case '(':
return Token.OPENPAREN;
case ')':
return Token.CLOSEPAREN;
case '[':
return Token.OPENBRACKET;
case ']':
return Token.CLOSEBRACKET;
case '{':
return Token.OPENBRACE;
case '}':
return Token.CLOSEBRACE;
case ':':
return Token.COLON;
case ';':
return Token.SEMICOLON;
case ',':
return Token.COMMA;
case '|':
return Token.OR;
case '.':
if (ch() == '.') {
position++;
if (ch() == '.') {
position++;
return Token.ELLIPSIS;
}
}
return Token.INVALID;
case '"':
case '\'':
while (!atEnd()) {
if (ch() == c) {
position++;
return Token.STRING;
}
position++;
}
return Token.INVALID;
default:
return Token.INVALID;
}
}
}
}