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notepad-plus-plus/lexilla/lexers/LexJSON.cxx

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14 KiB

// Scintilla source code edit control
/**
* @file LexJSON.cxx
* @date February 19, 2016
* @brief Lexer for JSON and JSON-LD formats
* @author nkmathew
*
* The License.txt file describes the conditions under which this software may
* be distributed.
*
*/
#include <cstdlib>
#include <cassert>
#include <cctype>
#include <cstdio>
#include <string>
#include <string_view>
#include <vector>
#include <map>
#include <functional>
#include "ILexer.h"
#include "Scintilla.h"
#include "SciLexer.h"
#include "WordList.h"
#include "LexAccessor.h"
#include "StyleContext.h"
#include "CharacterSet.h"
#include "LexerModule.h"
#include "OptionSet.h"
#include "DefaultLexer.h"
using namespace Scintilla;
using namespace Lexilla;
namespace {
const char *const JSONWordListDesc[] = {
"JSON Keywords",
"JSON-LD Keywords",
0
};
/**
* Used to detect compact IRI/URLs in JSON-LD without first looking ahead for the
* colon separating the prefix and suffix
*
* https://www.w3.org/TR/json-ld/#dfn-compact-iri
*/
struct CompactIRI {
int colonCount;
bool foundInvalidChar;
CharacterSet setCompactIRI;
CompactIRI() {
colonCount = 0;
foundInvalidChar = false;
setCompactIRI = CharacterSet(CharacterSet::setAlpha, "$_-");
}
void resetState() {
colonCount = 0;
foundInvalidChar = false;
}
void checkChar(int ch) {
if (ch == ':') {
colonCount++;
} else {
foundInvalidChar |= !setCompactIRI.Contains(ch);
}
}
bool shouldHighlight() const {
return !foundInvalidChar && colonCount == 1;
}
};
/**
* Keeps track of escaped characters in strings as per:
*
* https://tools.ietf.org/html/rfc7159#section-7
*/
struct EscapeSequence {
int digitsLeft;
CharacterSet setHexDigits;
CharacterSet setEscapeChars;
EscapeSequence() {
digitsLeft = 0;
setHexDigits = CharacterSet(CharacterSet::setDigits, "ABCDEFabcdef");
setEscapeChars = CharacterSet(CharacterSet::setNone, "\\\"tnbfru/");
}
// Returns true if the following character is a valid escaped character
bool newSequence(int nextChar) {
digitsLeft = 0;
if (nextChar == 'u') {
digitsLeft = 5;
} else if (!setEscapeChars.Contains(nextChar)) {
return false;
}
return true;
}
bool atEscapeEnd() const {
return digitsLeft <= 0;
}
bool isInvalidChar(int currChar) const {
return !setHexDigits.Contains(currChar);
}
};
struct OptionsJSON {
bool foldCompact;
bool fold;
bool allowComments;
bool escapeSequence;
OptionsJSON() {
foldCompact = false;
fold = false;
allowComments = false;
escapeSequence = false;
}
};
struct OptionSetJSON : public OptionSet<OptionsJSON> {
OptionSetJSON() {
DefineProperty("lexer.json.escape.sequence", &OptionsJSON::escapeSequence,
"Set to 1 to enable highlighting of escape sequences in strings");
DefineProperty("lexer.json.allow.comments", &OptionsJSON::allowComments,
"Set to 1 to enable highlighting of line/block comments in JSON");
DefineProperty("fold.compact", &OptionsJSON::foldCompact);
DefineProperty("fold", &OptionsJSON::fold);
DefineWordListSets(JSONWordListDesc);
}
};
class LexerJSON : public DefaultLexer {
OptionsJSON options;
OptionSetJSON optSetJSON;
EscapeSequence escapeSeq;
WordList keywordsJSON;
WordList keywordsJSONLD;
CharacterSet setOperators;
CharacterSet setURL;
CharacterSet setKeywordJSONLD;
CharacterSet setKeywordJSON;
CompactIRI compactIRI;
static bool IsNextNonWhitespace(LexAccessor &styler, Sci_Position start, char ch) {
Sci_Position i = 0;
while (i < 50) {
i++;
char curr = styler.SafeGetCharAt(start+i, '\0');
char next = styler.SafeGetCharAt(start+i+1, '\0');
bool atEOL = (curr == '\r' && next != '\n') || (curr == '\n');
if (curr == ch) {
return true;
} else if (!isspacechar(curr) || atEOL) {
return false;
}
}
return false;
}
/**
* Looks for the colon following the end quote
*
* Assumes property names of lengths no longer than a 100 characters.
* The colon is also expected to be less than 50 spaces after the end
* quote for the string to be considered a property name
*/
static bool AtPropertyName(LexAccessor &styler, Sci_Position start) {
Sci_Position i = 0;
bool escaped = false;
while (i < 100) {
i++;
char curr = styler.SafeGetCharAt(start+i, '\0');
if (escaped) {
escaped = false;
continue;
}
escaped = curr == '\\';
if (curr == '"') {
return IsNextNonWhitespace(styler, start+i, ':');
} else if (!curr) {
return false;
}
}
return false;
}
static bool IsNextWordInList(WordList &keywordList, CharacterSet wordSet,
StyleContext &context, LexAccessor &styler) {
char word[51];
Sci_Position currPos = (Sci_Position) context.currentPos;
int i = 0;
while (i < 50) {
char ch = styler.SafeGetCharAt(currPos + i);
if (!wordSet.Contains(ch)) {
break;
}
word[i] = ch;
i++;
}
word[i] = '\0';
return keywordList.InList(word);
}
public:
LexerJSON() :
DefaultLexer("json", SCLEX_JSON),
setOperators(CharacterSet::setNone, "[{}]:,"),
setURL(CharacterSet::setAlphaNum, "-._~:/?#[]@!$&'()*+,),="),
setKeywordJSONLD(CharacterSet::setAlpha, ":@"),
setKeywordJSON(CharacterSet::setAlpha, "$_") {
}
virtual ~LexerJSON() {}
int SCI_METHOD Version() const override {
return lvRelease5;
}
void SCI_METHOD Release() override {
delete this;
}
const char *SCI_METHOD PropertyNames() override {
return optSetJSON.PropertyNames();
}
int SCI_METHOD PropertyType(const char *name) override {
return optSetJSON.PropertyType(name);
}
const char *SCI_METHOD DescribeProperty(const char *name) override {
return optSetJSON.DescribeProperty(name);
}
Sci_Position SCI_METHOD PropertySet(const char *key, const char *val) override {
if (optSetJSON.PropertySet(&options, key, val)) {
return 0;
}
return -1;
}
const char * SCI_METHOD PropertyGet(const char *key) override {
return optSetJSON.PropertyGet(key);
}
Sci_Position SCI_METHOD WordListSet(int n, const char *wl) override {
WordList *wordListN = 0;
switch (n) {
case 0:
wordListN = &keywordsJSON;
break;
case 1:
wordListN = &keywordsJSONLD;
break;
}
Sci_Position firstModification = -1;
if (wordListN) {
if (wordListN->Set(wl)) {
firstModification = 0;
}
}
return firstModification;
}
void *SCI_METHOD PrivateCall(int, void *) override {
return 0;
}
static ILexer5 *LexerFactoryJSON() {
return new LexerJSON;
}
const char *SCI_METHOD DescribeWordListSets() override {
return optSetJSON.DescribeWordListSets();
}
void SCI_METHOD Lex(Sci_PositionU startPos,
Sci_Position length,
int initStyle,
IDocument *pAccess) override;
void SCI_METHOD Fold(Sci_PositionU startPos,
Sci_Position length,
int initStyle,
IDocument *pAccess) override;
};
void SCI_METHOD LexerJSON::Lex(Sci_PositionU startPos,
Sci_Position length,
int initStyle,
IDocument *pAccess) {
LexAccessor styler(pAccess);
StyleContext context(startPos, length, initStyle, styler);
int stringStyleBefore = SCE_JSON_STRING;
while (context.More()) {
switch (context.state) {
case SCE_JSON_BLOCKCOMMENT:
if (context.Match("*/")) {
context.Forward();
context.ForwardSetState(SCE_JSON_DEFAULT);
}
break;
case SCE_JSON_LINECOMMENT:
if (context.MatchLineEnd()) {
context.SetState(SCE_JSON_DEFAULT);
}
break;
case SCE_JSON_STRINGEOL:
if (context.atLineStart) {
context.SetState(SCE_JSON_DEFAULT);
}
break;
case SCE_JSON_ESCAPESEQUENCE:
escapeSeq.digitsLeft--;
if (!escapeSeq.atEscapeEnd()) {
if (escapeSeq.isInvalidChar(context.ch)) {
context.SetState(SCE_JSON_ERROR);
}
break;
}
if (context.ch == '"') {
context.SetState(stringStyleBefore);
context.ForwardSetState(SCE_JSON_DEFAULT);
} else if (context.ch == '\\') {
if (!escapeSeq.newSequence(context.chNext)) {
context.SetState(SCE_JSON_ERROR);
}
context.Forward();
} else {
context.SetState(stringStyleBefore);
if (context.atLineEnd) {
context.ChangeState(SCE_JSON_STRINGEOL);
}
}
break;
case SCE_JSON_PROPERTYNAME:
case SCE_JSON_STRING:
if (context.ch == '"') {
if (compactIRI.shouldHighlight()) {
context.ChangeState(SCE_JSON_COMPACTIRI);
context.ForwardSetState(SCE_JSON_DEFAULT);
compactIRI.resetState();
} else {
context.ForwardSetState(SCE_JSON_DEFAULT);
}
} else if (context.atLineEnd) {
context.ChangeState(SCE_JSON_STRINGEOL);
} else if (context.ch == '\\') {
stringStyleBefore = context.state;
if (options.escapeSequence) {
context.SetState(SCE_JSON_ESCAPESEQUENCE);
if (!escapeSeq.newSequence(context.chNext)) {
context.SetState(SCE_JSON_ERROR);
}
}
context.Forward();
} else if (context.Match("https://") ||
context.Match("http://") ||
context.Match("ssh://") ||
context.Match("git://") ||
context.Match("svn://") ||
context.Match("ftp://") ||
context.Match("mailto:")) {
// Handle most common URI schemes only
stringStyleBefore = context.state;
context.SetState(SCE_JSON_URI);
} else if (context.ch == '@') {
// https://www.w3.org/TR/json-ld/#dfn-keyword
if (IsNextWordInList(keywordsJSONLD, setKeywordJSONLD, context, styler)) {
stringStyleBefore = context.state;
context.SetState(SCE_JSON_LDKEYWORD);
}
} else {
compactIRI.checkChar(context.ch);
}
break;
case SCE_JSON_LDKEYWORD:
case SCE_JSON_URI:
if ((!setKeywordJSONLD.Contains(context.ch) &&
(context.state == SCE_JSON_LDKEYWORD)) ||
(!setURL.Contains(context.ch))) {
context.SetState(stringStyleBefore);
}
if (context.ch == '"') {
context.ForwardSetState(SCE_JSON_DEFAULT);
} else if (context.atLineEnd) {
context.ChangeState(SCE_JSON_STRINGEOL);
}
break;
case SCE_JSON_OPERATOR:
case SCE_JSON_NUMBER:
context.SetState(SCE_JSON_DEFAULT);
break;
case SCE_JSON_ERROR:
if (context.MatchLineEnd()) {
context.SetState(SCE_JSON_DEFAULT);
}
break;
case SCE_JSON_KEYWORD:
if (!setKeywordJSON.Contains(context.ch)) {
context.SetState(SCE_JSON_DEFAULT);
}
break;
}
if (context.state == SCE_JSON_DEFAULT) {
if (context.ch == '"') {
compactIRI.resetState();
context.SetState(SCE_JSON_STRING);
Sci_Position currPos = static_cast<Sci_Position>(context.currentPos);
if (AtPropertyName(styler, currPos)) {
context.SetState(SCE_JSON_PROPERTYNAME);
}
} else if (setOperators.Contains(context.ch)) {
context.SetState(SCE_JSON_OPERATOR);
} else if (options.allowComments && context.Match("/*")) {
context.SetState(SCE_JSON_BLOCKCOMMENT);
context.Forward();
} else if (options.allowComments && context.Match("//")) {
context.SetState(SCE_JSON_LINECOMMENT);
} else if (setKeywordJSON.Contains(context.ch)) {
if (IsNextWordInList(keywordsJSON, setKeywordJSON, context, styler)) {
context.SetState(SCE_JSON_KEYWORD);
}
}
bool numberStart =
IsADigit(context.ch) && (context.chPrev == '+'||
context.chPrev == '-' ||
context.atLineStart ||
IsASpace(context.chPrev) ||
setOperators.Contains(context.chPrev));
bool exponentPart =
tolower(context.ch) == 'e' &&
IsADigit(context.chPrev) &&
(IsADigit(context.chNext) ||
context.chNext == '+' ||
context.chNext == '-');
bool signPart =
(context.ch == '-' || context.ch == '+') &&
((tolower(context.chPrev) == 'e' && IsADigit(context.chNext)) ||
((IsASpace(context.chPrev) || setOperators.Contains(context.chPrev))
&& IsADigit(context.chNext)));
bool adjacentDigit =
IsADigit(context.ch) && IsADigit(context.chPrev);
bool afterExponent = IsADigit(context.ch) && tolower(context.chPrev) == 'e';
bool dotPart = context.ch == '.' &&
IsADigit(context.chPrev) &&
IsADigit(context.chNext);
bool afterDot = IsADigit(context.ch) && context.chPrev == '.';
if (numberStart ||
exponentPart ||
signPart ||
adjacentDigit ||
dotPart ||
afterExponent ||
afterDot) {
context.SetState(SCE_JSON_NUMBER);
} else if (context.state == SCE_JSON_DEFAULT && !IsASpace(context.ch)) {
context.SetState(SCE_JSON_ERROR);
}
}
context.Forward();
}
context.Complete();
}
void SCI_METHOD LexerJSON::Fold(Sci_PositionU startPos,
Sci_Position length,
int,
IDocument *pAccess) {
if (!options.fold) {
return;
}
LexAccessor styler(pAccess);
Sci_PositionU currLine = styler.GetLine(startPos);
Sci_PositionU endPos = startPos + length;
int currLevel = SC_FOLDLEVELBASE;
if (currLine > 0)
currLevel = styler.LevelAt(currLine - 1) >> 16;
int nextLevel = currLevel;
int visibleChars = 0;
for (Sci_PositionU i = startPos; i < endPos; i++) {
char curr = styler.SafeGetCharAt(i);
char next = styler.SafeGetCharAt(i+1);
bool atEOL = (curr == '\r' && next != '\n') || (curr == '\n');
if (styler.StyleAt(i) == SCE_JSON_OPERATOR) {
if (curr == '{' || curr == '[') {
nextLevel++;
} else if (curr == '}' || curr == ']') {
nextLevel--;
}
}
if (atEOL || i == (endPos-1)) {
int level = currLevel | nextLevel << 16;
if (!visibleChars && options.foldCompact) {
level |= SC_FOLDLEVELWHITEFLAG;
} else if (nextLevel > currLevel) {
level |= SC_FOLDLEVELHEADERFLAG;
}
if (level != styler.LevelAt(currLine)) {
styler.SetLevel(currLine, level);
}
currLine++;
currLevel = nextLevel;
visibleChars = 0;
}
if (!isspacechar(curr)) {
visibleChars++;
}
}
}
}
extern const LexerModule lmJSON(SCLEX_JSON,
LexerJSON::LexerFactoryJSON,
"json",
JSONWordListDesc);