551 lines
15 KiB
Java
551 lines
15 KiB
Java
/**
|
||
* Copyright (c) 2011-2019, James Zhan 詹波 (jfinal@126.com).
|
||
*
|
||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||
* you may not use this file except in compliance with the License.
|
||
* You may obtain a copy of the License at
|
||
*
|
||
* http://www.apache.org/licenses/LICENSE-2.0
|
||
*
|
||
* Unless required by applicable law or agreed to in writing, software
|
||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
* See the License for the specific language governing permissions and
|
||
* limitations under the License.
|
||
*/
|
||
|
||
package com.jfinal.template.stat;
|
||
|
||
import java.util.ArrayList;
|
||
import java.util.List;
|
||
|
||
/**
|
||
* DKFF(Dynamic Key Feature Forward) Lexer
|
||
*/
|
||
class Lexer {
|
||
|
||
static final char EOF = (char)-1;
|
||
static final int TEXT_STATE_DIAGRAM = 999;
|
||
|
||
char[] buf;
|
||
int state = 0;
|
||
int lexemeBegin = 0;
|
||
int forward = 0;
|
||
int beginRow = 1;
|
||
int forwardRow = 1;
|
||
TextToken previousTextToken = null;
|
||
|
||
List<Token> tokens = new ArrayList<Token>();
|
||
String fileName;
|
||
|
||
public Lexer(StringBuilder content, String fileName) {
|
||
int len = content.length();
|
||
buf = new char[len + 1];
|
||
content.getChars(0, content.length(), buf, 0);
|
||
buf[len] = EOF;
|
||
this.fileName = fileName;
|
||
}
|
||
|
||
/**
|
||
* 进入每个扫描方法之前 peek() 处于可用状态，不需要 next()
|
||
* 每个扫描方法内部是否要 next() 移动，取决定具体情况
|
||
* 每个扫描方法成功返回前，将 forward 置于下一次扫描需要处理的地方
|
||
* 让下个扫描方法不必 next()
|
||
* 紧靠 scanText() 之前的扫描方法在失败后必须保持住forward
|
||
* 这是 scanText() 可以一直向前的保障
|
||
*/
|
||
public List<Token> scan() {
|
||
while (peek() != EOF) {
|
||
if (peek() == '#') {
|
||
if (scanDire()) {
|
||
continue ;
|
||
}
|
||
if (scanSingleLineComment()) {
|
||
continue ;
|
||
}
|
||
if (scanMultiLineComment()) {
|
||
continue ;
|
||
}
|
||
if (scanNoParse()) {
|
||
continue ;
|
||
}
|
||
}
|
||
|
||
scanText();
|
||
}
|
||
return tokens;
|
||
}
|
||
|
||
/**
|
||
* 指令模式与解析规则
|
||
* 1：指令 pattern
|
||
* #(p)
|
||
* #id(p)
|
||
* #define id(p)
|
||
* #@id(p) / #@id?(p)
|
||
* #else / #end
|
||
*
|
||
* 2：关键字类型指令在获取到关键字以后，必须要正确解析出后续内容，否则抛异常
|
||
*
|
||
* 3：非关键字类型指令只有在本行内出现 # id ( 三个序列以后，才要求正确解析出后续内容
|
||
* 否则当成普通文本
|
||
*/
|
||
boolean scanDire() {
|
||
String id = null;
|
||
StringBuilder para = null;
|
||
Token idToken = null;
|
||
Token paraToken = null;
|
||
while (true) {
|
||
switch (state) {
|
||
case 0:
|
||
if (peek() == '#') { // #
|
||
next();
|
||
skipBlanks();
|
||
state = 1;
|
||
continue ;
|
||
}
|
||
return fail();
|
||
case 1:
|
||
if (peek() == '(') { // # (
|
||
para = scanPara("");
|
||
idToken = new Token(Symbol.OUTPUT, beginRow);
|
||
paraToken = new ParaToken(para, beginRow);
|
||
return addOutputToken(idToken, paraToken);
|
||
}
|
||
if (CharTable.isLetter(peek())) { // # id
|
||
state = 10;
|
||
continue ;
|
||
}
|
||
if (peek() == '@') { // # @
|
||
next();
|
||
skipBlanks();
|
||
if (CharTable.isLetter(peek())) { // # @ id
|
||
state = 20;
|
||
continue ;
|
||
}
|
||
}
|
||
return fail();
|
||
// -----------------------------------------------------
|
||
case 10: // # id
|
||
id = scanId();
|
||
Symbol symbol = Symbol.getKeywordSym(id);
|
||
// 非关键字指令
|
||
if (symbol == null) {
|
||
state = 11;
|
||
continue ;
|
||
}
|
||
|
||
// define 指令
|
||
if (symbol == Symbol.DEFINE) {
|
||
state = 12;
|
||
continue ;
|
||
}
|
||
|
||
// 在支持 #seleif 的基础上，支持 #else if
|
||
if (symbol == Symbol.ELSE) {
|
||
if (foundFollowingIf()) {
|
||
id = "else if";
|
||
symbol = Symbol.ELSEIF;
|
||
}
|
||
}
|
||
|
||
// 无参关键字指令
|
||
if (symbol.noPara()) {
|
||
return addNoParaToken(new Token(symbol, id, beginRow));
|
||
}
|
||
|
||
// 有参关键字指令
|
||
skipBlanks();
|
||
if (peek() == '(') {
|
||
para = scanPara(id);
|
||
idToken = new Token(symbol, beginRow);
|
||
paraToken = new ParaToken(para, beginRow);
|
||
return addIdParaToken(idToken, paraToken);
|
||
}
|
||
throw new ParseException("#" + id + " directive requires parentheses \"()\"", new Location(fileName, beginRow));
|
||
case 11: // 用户自定义指令必须有参数
|
||
skipBlanks();
|
||
if (peek() == '(') {
|
||
para = scanPara(id);
|
||
idToken = new Token(Symbol.ID, id, beginRow);
|
||
paraToken = new ParaToken(para, beginRow);
|
||
return addIdParaToken(idToken, paraToken);
|
||
}
|
||
return fail(); // 用户自定义指令在没有左括号的情况下当作普通文本
|
||
case 12: // 处理 "# define id (para)" 指令
|
||
skipBlanks();
|
||
if (CharTable.isLetter(peek())) {
|
||
id = scanId(); // 模板函数名称
|
||
skipBlanks();
|
||
if (peek() == '(') {
|
||
para = scanPara("define " + id);
|
||
idToken = new Token(Symbol.DEFINE, id, beginRow);
|
||
paraToken = new ParaToken(para, beginRow);
|
||
return addIdParaToken(idToken, paraToken);
|
||
}
|
||
throw new ParseException("#define " + id + " : template function definition requires parentheses \"()\"", new Location(fileName, beginRow));
|
||
}
|
||
throw new ParseException("#define directive requires identifier as a function name", new Location(fileName, beginRow));
|
||
case 20: // # @ id
|
||
id = scanId();
|
||
skipBlanks();
|
||
boolean hasQuestionMark = peek() == '?';
|
||
if (hasQuestionMark) {
|
||
next();
|
||
skipBlanks();
|
||
}
|
||
if (peek() == '(') {
|
||
para = scanPara(hasQuestionMark ? "@" + id + "?" : "@" + id);
|
||
idToken = new Token(hasQuestionMark ? Symbol.CALL_IF_DEFINED : Symbol.CALL, id, beginRow);
|
||
paraToken = new ParaToken(para, beginRow);
|
||
return addIdParaToken(idToken, paraToken);
|
||
}
|
||
return fail();
|
||
default :
|
||
return fail();
|
||
}
|
||
}
|
||
}
|
||
|
||
boolean foundFollowingIf() {
|
||
int p = forward;
|
||
while (CharTable.isBlank(buf[p])) {p++;}
|
||
if (buf[p++] == 'i') {
|
||
if (buf[p++] == 'f') {
|
||
while (CharTable.isBlank(buf[p])) {p++;}
|
||
// 要求出现 '(' 才认定解析成功，为了支持这种场景: #else if you ...
|
||
if (buf[p] == '(') {
|
||
forward = p;
|
||
return true;
|
||
}
|
||
}
|
||
}
|
||
return false;
|
||
}
|
||
|
||
/**
|
||
* 调用者已确定以字母或下划线开头，故一定可以获取到 id值
|
||
*/
|
||
String scanId() {
|
||
int idStart = forward;
|
||
while (CharTable.isLetterOrDigit(next())) {
|
||
;
|
||
}
|
||
return subBuf(idStart, forward - 1).toString();
|
||
}
|
||
|
||
/**
|
||
* 扫描指令参数，成功则返回，否则抛出词法分析异常
|
||
*/
|
||
StringBuilder scanPara(String id) {
|
||
char quotes = '"';
|
||
int localState = 0;
|
||
int parenDepth = 1; // 指令后面参数的第一个 '(' 深度为 1
|
||
next();
|
||
int paraStart = forward;
|
||
while (true) {
|
||
switch (localState) {
|
||
case 0:
|
||
for (char c=peek(); true; c=next()) {
|
||
if (c == ')') {
|
||
parenDepth--;
|
||
if (parenDepth == 0) { // parenDepth 不可能小于0，因为初始值为 1
|
||
next();
|
||
return subBuf(paraStart, forward - 2);
|
||
}
|
||
continue ;
|
||
}
|
||
|
||
if (c == '(') {
|
||
parenDepth++;
|
||
continue ;
|
||
}
|
||
|
||
if (c == '"' || c == '\'') {
|
||
quotes = c;
|
||
localState = 1;
|
||
break ;
|
||
}
|
||
|
||
if (CharTable.isExprChar(c)) {
|
||
continue ;
|
||
}
|
||
|
||
if (c == EOF) {
|
||
throw new ParseException("#" + id + " parameter can not match the end char ')'", new Location(fileName, beginRow));
|
||
}
|
||
|
||
throw new ParseException("#" + id + " parameter exists illegal char: '" + c + "'", new Location(fileName, beginRow));
|
||
}
|
||
break ;
|
||
case 1:
|
||
for (char c=next(); true; c=next()) {
|
||
if (c == quotes) {
|
||
if (buf[forward - 1] != '\\') { // 前一个字符不是转义字符
|
||
next();
|
||
localState = 0;
|
||
break ;
|
||
} else {
|
||
continue ;
|
||
}
|
||
}
|
||
|
||
if (c == EOF) {
|
||
throw new ParseException("#" + id + " parameter error, the string parameter not ending", new Location(fileName, beginRow));
|
||
}
|
||
}
|
||
break ;
|
||
}
|
||
}
|
||
}
|
||
|
||
/**
|
||
* 单行注释，开始状态 100，关注换行与 EOF
|
||
*/
|
||
boolean scanSingleLineComment() {
|
||
while (true) {
|
||
switch (state) {
|
||
case 100:
|
||
if (peek() == '#' && next() == '#' && next() == '#') {
|
||
state = 101;
|
||
continue ;
|
||
}
|
||
return fail();
|
||
case 101:
|
||
for (char c=next(); true; c=next()) {
|
||
if (c == '\n') {
|
||
if (deletePreviousTextTokenBlankTails()) {
|
||
return prepareNextScan(1);
|
||
} else {
|
||
return prepareNextScan(0);
|
||
}
|
||
}
|
||
if (c == EOF) {
|
||
deletePreviousTextTokenBlankTails();
|
||
return prepareNextScan(0);
|
||
}
|
||
}
|
||
default :
|
||
return fail();
|
||
}
|
||
}
|
||
}
|
||
|
||
/**
|
||
* 多行注释，开始状态 200，关注结尾标记与 EOF
|
||
*/
|
||
boolean scanMultiLineComment() {
|
||
while (true) {
|
||
switch (state) {
|
||
case 200:
|
||
if (peek() == '#' && next() == '-' && next() == '-') {
|
||
state = 201;
|
||
continue ;
|
||
}
|
||
return fail();
|
||
case 201:
|
||
for (char c=next(); true; c=next()) {
|
||
if (c == '-' && buf[forward + 1] == '-' && buf[forward + 2] == '#') {
|
||
forward = forward + 3;
|
||
if (lookForwardLineFeedAndEof() && deletePreviousTextTokenBlankTails()) {
|
||
return prepareNextScan(peek() != EOF ? 1 : 0);
|
||
} else {
|
||
return prepareNextScan(0);
|
||
}
|
||
}
|
||
if (c == EOF) {
|
||
throw new ParseException("The multiline comment start block \"#--\" can not match the end block: \"--#\"", new Location(fileName, beginRow));
|
||
}
|
||
}
|
||
default :
|
||
return fail();
|
||
}
|
||
}
|
||
}
|
||
|
||
/**
|
||
* 非解析块，开始状态 300，关注结尾标记与 EOF
|
||
*/
|
||
boolean scanNoParse() {
|
||
while (true) {
|
||
switch (state) {
|
||
case 300:
|
||
if (peek() == '#' && next() == '[' && next() == '[') {
|
||
state = 301;
|
||
continue ;
|
||
}
|
||
return fail();
|
||
case 301:
|
||
for (char c=next(); true; c=next()) {
|
||
if (c == ']' && buf[forward + 1] == ']' && buf[forward + 2] == '#') {
|
||
addTextToken(subBuf(lexemeBegin + 3, forward - 1)); // NoParse 块使用 TextToken
|
||
return prepareNextScan(3);
|
||
}
|
||
if (c == EOF) {
|
||
throw new ParseException("The \"no parse\" start block \"#[[\" can not match the end block: \"]]#\"", new Location(fileName, beginRow));
|
||
}
|
||
}
|
||
default :
|
||
return fail();
|
||
}
|
||
}
|
||
}
|
||
|
||
boolean scanText() {
|
||
for (char c=peek(); true; c=next()) {
|
||
if (c == '#' || c == EOF) {
|
||
addTextToken(subBuf(lexemeBegin, forward - 1));
|
||
return prepareNextScan(0);
|
||
}
|
||
}
|
||
}
|
||
|
||
boolean fail() {
|
||
if (state < 300) {
|
||
forward = lexemeBegin;
|
||
forwardRow = beginRow;
|
||
}
|
||
if (state < 100) {
|
||
state = 100;
|
||
} else if (state < 200) {
|
||
state = 200;
|
||
} else if (state < 300) {
|
||
state = 300;
|
||
} else {
|
||
state = TEXT_STATE_DIAGRAM;
|
||
}
|
||
return false;
|
||
}
|
||
|
||
char next() {
|
||
if (buf[forward] == '\n') {
|
||
forwardRow++;
|
||
}
|
||
return buf[++forward];
|
||
}
|
||
|
||
char peek() {
|
||
return buf[forward];
|
||
}
|
||
|
||
void skipBlanks() {
|
||
while (CharTable.isBlank(buf[forward])) {
|
||
next();
|
||
}
|
||
}
|
||
|
||
/**
|
||
* scanPara 与 scanNoParse 存在 start > end 的情况
|
||
*/
|
||
StringBuilder subBuf(int start, int end) {
|
||
if (start > end) {
|
||
return null;
|
||
}
|
||
StringBuilder ret = new StringBuilder(end - start + 1);
|
||
for (int i=start; i<=end; i++) {
|
||
ret.append(buf[i]);
|
||
}
|
||
return ret;
|
||
}
|
||
|
||
boolean prepareNextScan(int moveForward) {
|
||
for (int i=0; i<moveForward; i++) {
|
||
next();
|
||
}
|
||
|
||
state = 0;
|
||
lexemeBegin = forward;
|
||
beginRow = forwardRow;
|
||
return true;
|
||
}
|
||
|
||
void addTextToken(StringBuilder text) {
|
||
if (text == null || text.length() == 0) {
|
||
return ;
|
||
}
|
||
|
||
if (previousTextToken != null) {
|
||
previousTextToken.append(text);
|
||
} else {
|
||
previousTextToken = new TextToken(text, beginRow);
|
||
tokens.add(previousTextToken);
|
||
}
|
||
}
|
||
|
||
// 输出指令不对前后空白与换行进行任何处理，直接调用 tokens.add(...)
|
||
boolean addOutputToken(Token idToken, Token paraToken) {
|
||
tokens.add(idToken);
|
||
tokens.add(paraToken);
|
||
previousTextToken = null;
|
||
return prepareNextScan(0);
|
||
}
|
||
|
||
// 向前看后续是否跟随的是空白 + 换行或者是空白 + EOF，是则表示当前指令后续没有其它有用内容
|
||
boolean lookForwardLineFeedAndEof() {
|
||
int forwardBak = forward;
|
||
int forwardRowBak = forwardRow;
|
||
for (char c=peek(); true; c=next()) {
|
||
if (CharTable.isBlank(c)) {
|
||
continue ;
|
||
}
|
||
if (c == '\n' || c == EOF) {
|
||
return true;
|
||
}
|
||
forward = forwardBak;
|
||
forwardRow = forwardRowBak;
|
||
return false;
|
||
}
|
||
}
|
||
|
||
/**
|
||
* 带参指令处于独立行时删除前后空白字符，并且再删除一个后续的换行符
|
||
* 处于独立行是指：向前看无有用内容，在前面情况成立的基础之上
|
||
* 再向后看如果也无可用内容，前一个条件成立才开执行后续动作
|
||
*
|
||
* 向前看时 forward 在移动，意味着正在删除空白字符(通过 lookForwardLineFeed()方法)
|
||
* 向后看时也会在碰到空白 + '\n' 时删空白字符 (通过 deletePreviousTextTokenBlankTails()方法)
|
||
*/
|
||
boolean addIdParaToken(Token idToken, Token paraToken) {
|
||
tokens.add(idToken);
|
||
tokens.add(paraToken);
|
||
|
||
// if (lookForwardLineFeed() && (deletePreviousTextTokenBlankTails() || lexemeBegin == 0)) {
|
||
if (lookForwardLineFeedAndEof() && deletePreviousTextTokenBlankTails()) {
|
||
prepareNextScan(peek() != EOF ? 1 : 0);
|
||
} else {
|
||
prepareNextScan(0);
|
||
}
|
||
previousTextToken = null;
|
||
return true;
|
||
}
|
||
|
||
// 处理前后空白的逻辑与 addIdParaToken() 基本一样，仅仅多了一个对于紧随空白的 next() 操作
|
||
boolean addNoParaToken(Token noParaToken) {
|
||
tokens.add(noParaToken);
|
||
if (CharTable.isBlank(peek())) {
|
||
next(); // 无参指令之后紧随的一个空白字符仅为分隔符，不参与后续扫描
|
||
}
|
||
|
||
if (lookForwardLineFeedAndEof() && deletePreviousTextTokenBlankTails()) {
|
||
prepareNextScan(peek() != EOF ? 1 : 0);
|
||
} else {
|
||
prepareNextScan(0);
|
||
}
|
||
previousTextToken = null;
|
||
return true;
|
||
}
|
||
|
||
/**
|
||
* 1：当前指令前方仍然是指令 (previousTextToken 为 null)，直接返回 true
|
||
* 2：当前指令前方为 TextToken 时的处理逻辑与返回值完全依赖于 TextToken.deleteBlankTails()
|
||
*/
|
||
boolean deletePreviousTextTokenBlankTails() {
|
||
// return previousTextToken != null ? previousTextToken.deleteBlankTails() : false;
|
||
return previousTextToken == null || previousTextToken.deleteBlankTails();
|
||
}
|
||
}
|
||
|
||
|
||
|
||
|