Update Scintilla to version 3.5.7

[TortoiseGit.git] / ext / scintilla / lexers / LexOScript.cxx

// Scintilla source code edit control
/** @file LexOScript.cxx
 ** Lexer for OScript sources; ocx files and/or OSpace dumps.
 ** OScript is a programming language used to develop applications for the
 ** Livelink server platform.
 **/
// Written by Ferdinand Prantl <prantlf@gmail.com>, inspired by the code from
// LexVB.cxx and LexPascal.cxx. The License.txt file describes the conditions
// under which this software may be distributed.

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stdarg.h>
#include <assert.h>
#include <ctype.h>

#include "ILexer.h"
#include "Scintilla.h"
#include "SciLexer.h"

#include "WordList.h"
#include "LexAccessor.h"
#include "Accessor.h"
#include "StyleContext.h"
#include "CharacterSet.h"
#include "LexerModule.h"

#ifdef SCI_NAMESPACE
using namespace Scintilla;
#endif

// -----------------------------------------
// Functions classifying a single character.

// This function is generic and should be probably moved to CharSet.h where
// IsAlphaNumeric the others reside.
inline bool IsAlpha(int ch) {
        return (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z');
}

static inline bool IsIdentifierChar(int ch) {
        // Identifiers cannot contain non-ASCII letters; a word with non-English
        // language-specific characters cannot be an identifier.
        return IsAlphaNumeric(ch) || ch == '_';
}

static inline bool IsIdentifierStart(int ch) {
        // Identifiers cannot contain non-ASCII letters; a word with non-English
        // language-specific characters cannot be an identifier.
        return IsAlpha(ch) || ch == '_';
}

static inline bool IsNumberChar(int ch, int chNext) {
        // Numeric constructs are not checked for lexical correctness. They are
        // expected to look like +1.23-E9 but actually any bunch of the following
        // characters will be styled as number.
        // KNOWN PROBLEM: if you put + or - operators immediately after a number
        // and the next operand starts with the letter E, the operator will not be
        // recognized and it will be styled together with the preceding number.
        // This should not occur; at least not often. The coding style recommends
        // putting spaces around operators.
        return IsADigit(ch) || toupper(ch) == 'E' || ch == '.' ||
                   ((ch == '-' || ch == '+') && toupper(chNext) == 'E');
}

// This function checks for the start or a natural number without any symbols
// or operators as a prefix; the IsPrefixedNumberStart should be called
// immediately after this one to cover all possible numeric constructs.
static inline bool IsNaturalNumberStart(int ch) {
        return IsADigit(ch) != 0;
}

static inline bool IsPrefixedNumberStart(int ch, int chNext) {
        // KNOWN PROBLEM: if you put + or - operators immediately before a number
        // the operator will not be recognized and it will be styled together with
        // the succeeding number. This should not occur; at least not often. The
        // coding style recommends putting spaces around operators.
        return (ch == '.' || ch == '-' || ch == '+') && IsADigit(chNext);
}

static inline bool IsOperator(int ch) {
        return strchr("%^&*()-+={}[]:;<>,/?!.~|\\", ch) != NULL;
}

// ---------------------------------------------------------------
// Functions classifying a token currently processed in the lexer.

// Checks if the current line starts with the preprocessor directive used
// usually to introduce documentation comments: #ifdef DOC. This method is
// supposed to be called if the line has been recognized as a preprocessor
// directive already.
static bool IsDocCommentStart(StyleContext &sc) {
        // Check the line back to its start only if the end looks promising.
        if (sc.LengthCurrent() == 10 && !IsAlphaNumeric(sc.ch)) {
                char s[11];
                sc.GetCurrentLowered(s, sizeof(s));
                return strcmp(s, "#ifdef doc") == 0;
        }
        return false;
}

// Checks if the current line starts with the preprocessor directive that
// is complementary to the #ifdef DOC start: #endif. This method is supposed
// to be called if the current state point to the documentation comment.
// QUESTIONAL ASSUMPTION: The complete #endif directive is not checked; just
// the starting #e. However, there is no other preprocessor directive with
// the same starting letter and thus this optimization should always work.
static bool IsDocCommentEnd(StyleContext &sc) {
        return sc.ch == '#' && sc.chNext == 'e';
}

class IdentifierClassifier {
        WordList &keywords;  // Passed from keywords property.
        WordList &constants; // Passed from keywords2 property.
        WordList &operators; // Passed from keywords3 property.
        WordList &types;     // Passed from keywords4 property.
        WordList &functions; // Passed from keywords5 property.
        WordList &objects;   // Passed from keywords6 property.

        IdentifierClassifier(IdentifierClassifier const&);
        IdentifierClassifier& operator=(IdentifierClassifier const&);

public:
        IdentifierClassifier(WordList *keywordlists[]) :
                keywords(*keywordlists[0]), constants(*keywordlists[1]),
                operators(*keywordlists[2]), types(*keywordlists[3]),
                functions(*keywordlists[4]), objects(*keywordlists[5])
        {}

        void ClassifyIdentifier(StyleContext &sc) {
                // Opening parenthesis following an identifier makes it a possible
                // function call.
                // KNOWN PROBLEM: If some whitespace is inserted between the
                // identifier and the parenthesis they will not be able to be
                // recognized as a function call. This should not occur; at
                // least not often. Such coding style would be weird.
                if (sc.Match('(')) {
                        char s[100];
                        sc.GetCurrentLowered(s, sizeof(s));
                        // Before an opening brace can be control statements and
                        // operators too; function call is the last option.
                        if (keywords.InList(s)) {
                                sc.ChangeState(SCE_OSCRIPT_KEYWORD);
                        } else if (operators.InList(s)) {
                                sc.ChangeState(SCE_OSCRIPT_OPERATOR);
                        } else if (functions.InList(s)) {
                                sc.ChangeState(SCE_OSCRIPT_FUNCTION);
                        } else {
                                sc.ChangeState(SCE_OSCRIPT_METHOD);
                        }
                        sc.SetState(SCE_OSCRIPT_OPERATOR);
                } else {
                        char s[100];
                        sc.GetCurrentLowered(s, sizeof(s));
                        // A dot following an identifier means an access to an object
                        // member. The related object identifier can be special.
                        // KNOWN PROBLEM: If there is whitespace between the identifier
                        // and the following dot, the identifier will not be recognized
                        // as an object in an object member access. If it is one of the
                        // listed static objects it will not be styled.
                        if (sc.Match('.') && objects.InList(s)) {
                                sc.ChangeState(SCE_OSCRIPT_OBJECT);
                                sc.SetState(SCE_OSCRIPT_OPERATOR);
                        } else {
                                if (keywords.InList(s)) {
                                        sc.ChangeState(SCE_OSCRIPT_KEYWORD);
                                } else if (constants.InList(s)) {
                                        sc.ChangeState(SCE_OSCRIPT_CONSTANT);
                                } else if (operators.InList(s)) {
                                        sc.ChangeState(SCE_OSCRIPT_OPERATOR);
                                } else if (types.InList(s)) {
                                        sc.ChangeState(SCE_OSCRIPT_TYPE);
                                } else if (functions.InList(s)) {
                                        sc.ChangeState(SCE_OSCRIPT_FUNCTION);
                                }
                                sc.SetState(SCE_OSCRIPT_DEFAULT);
                        }
                }
        }
};

// ------------------------------------------------
// Function colourising an excerpt of OScript code.

static void ColouriseOScriptDoc(unsigned int startPos, int length,
                                                                int initStyle, WordList *keywordlists[],
                                                                Accessor &styler) {
        // I wonder how whole-line styles ended by EOLN can escape the resetting
        // code in the loop below and overflow to the next line. Let us make sure
        // that a new line does not start with them carried from the previous one.
        // NOTE: An overflowing string is intentionally not checked; it reminds
        // the developer that the string must be ended on the same line.
        if (initStyle == SCE_OSCRIPT_LINE_COMMENT ||
                        initStyle == SCE_OSCRIPT_PREPROCESSOR) {
                initStyle = SCE_OSCRIPT_DEFAULT;
        }

        styler.StartAt(startPos);
        StyleContext sc(startPos, length, initStyle, styler);
        IdentifierClassifier identifierClassifier(keywordlists);

        // It starts with true at the beginning of a line and changes to false as
        // soon as the first non-whitespace character has been processed.
        bool isFirstToken = true;
        // It starts with true at the beginning of a line and changes to false as
        // soon as the first identifier on the line is passed by.
        bool isFirstIdentifier = true; 
        // It becomes false when #ifdef DOC (the preprocessor directive often
        // used to start a documentation comment) is encountered and remain false
        // until the end of the documentation block is not detected. This is done
        // by checking for the complementary #endif preprocessor directive.
        bool endDocComment = false; 

        for (; sc.More(); sc.Forward()) {

                if (sc.atLineStart) {
                        isFirstToken = true;
                        isFirstIdentifier = true;
                // Detect the current state is neither whitespace nor identifier. It
                // means that no next identifier can be the first token on the line.
                } else if (isFirstIdentifier && sc.state != SCE_OSCRIPT_DEFAULT &&
                                   sc.state != SCE_OSCRIPT_IDENTIFIER) {
                        isFirstIdentifier = false;
                }

                // Check if the current state should be changed.
                if (sc.state == SCE_OSCRIPT_OPERATOR) {
                        // Multiple-symbol operators are marked by single characters.
                        sc.SetState(SCE_OSCRIPT_DEFAULT);
                } else if (sc.state == SCE_OSCRIPT_IDENTIFIER) {
                        if (!IsIdentifierChar(sc.ch)) {
                                // Colon after an identifier makes it a label if it is the
                                // first token on the line.
                                // KNOWN PROBLEM: If some whitespace is inserted between the
                                // identifier and the colon they will not be recognized as a
                                // label. This should not occur; at least not often. It would
                                // make the code structure less legible and examples in the
                                // Livelink documentation do not show it.
                                if (sc.Match(':') && isFirstIdentifier) {
                                        sc.ChangeState(SCE_OSCRIPT_LABEL);
                                        sc.ForwardSetState(SCE_OSCRIPT_DEFAULT);
                                } else {
                                        identifierClassifier.ClassifyIdentifier(sc);
                                }
                                // Avoid a sequence of two words be mistaken for a label. A
                                // switch case would be an example.
                                isFirstIdentifier = false;
                        }
                } else if (sc.state == SCE_OSCRIPT_GLOBAL) {
                        if (!IsIdentifierChar(sc.ch)) {
                                sc.SetState(SCE_OSCRIPT_DEFAULT);
                        }
                } else if (sc.state == SCE_OSCRIPT_PROPERTY) {
                        if (!IsIdentifierChar(sc.ch)) {
                                // Any member access introduced by the dot operator is
                                // initially marked as a property access. If an opening
                                // parenthesis is detected later it is changed to method call.
                                // KNOWN PROBLEM: The same as at the function call recognition
                                // for SCE_OSCRIPT_IDENTIFIER above.
                                if (sc.Match('(')) {
                                        sc.ChangeState(SCE_OSCRIPT_METHOD);
                                }
                                sc.SetState(SCE_OSCRIPT_DEFAULT);
                        }
                } else if (sc.state == SCE_OSCRIPT_NUMBER) {
                        if (!IsNumberChar(sc.ch, sc.chNext)) {
                                sc.SetState(SCE_OSCRIPT_DEFAULT);
                        }
                } else if (sc.state == SCE_OSCRIPT_SINGLEQUOTE_STRING) {
                        if (sc.ch == '\'') {
                                // Two consequential apostrophes convert to a single one.
                                if (sc.chNext == '\'') {
                                        sc.Forward();
                                } else {
                                        sc.ForwardSetState(SCE_OSCRIPT_DEFAULT);
                                }
                        } else if (sc.atLineEnd) {
                                sc.ForwardSetState(SCE_OSCRIPT_DEFAULT);
                        }
                } else if (sc.state == SCE_OSCRIPT_DOUBLEQUOTE_STRING) {
                        if (sc.ch == '\"') {
                                // Two consequential quotation marks convert to a single one.
                                if (sc.chNext == '\"') {
                                        sc.Forward();
                                } else {
                                        sc.ForwardSetState(SCE_OSCRIPT_DEFAULT);
                                }
                        } else if (sc.atLineEnd) {
                                sc.ForwardSetState(SCE_OSCRIPT_DEFAULT);
                        }
                } else if (sc.state == SCE_OSCRIPT_BLOCK_COMMENT) {
                        if (sc.Match('*', '/')) {
                                sc.Forward();
                                sc.ForwardSetState(SCE_OSCRIPT_DEFAULT);
                        }
                } else if (sc.state == SCE_OSCRIPT_LINE_COMMENT) {
                        if (sc.atLineEnd) {
                                sc.ForwardSetState(SCE_OSCRIPT_DEFAULT);
                        }
                } else if (sc.state == SCE_OSCRIPT_PREPROCESSOR) {
                        if (IsDocCommentStart(sc)) {
                                sc.ChangeState(SCE_OSCRIPT_DOC_COMMENT);
                                endDocComment = false;
                        } else if (sc.atLineEnd) {
                                sc.ForwardSetState(SCE_OSCRIPT_DEFAULT);
                        }
                } else if (sc.state == SCE_OSCRIPT_DOC_COMMENT) {
                        // KNOWN PROBLEM: The first line detected that would close a
                        // conditional preprocessor block (#endif) the documentation
                        // comment block will end. (Nested #if-#endif blocks are not
                        // supported. Hopefully it will not occur often that a line
                        // within the text block would stat with #endif.
                        if (isFirstToken && IsDocCommentEnd(sc)) {
                                endDocComment = true;
                        } else if (sc.atLineEnd && endDocComment) {
                                sc.ForwardSetState(SCE_OSCRIPT_DEFAULT);
                        }
                }

                // Check what state starts with the current character.
                if (sc.state == SCE_OSCRIPT_DEFAULT) {
                        if (sc.Match('\'')) {
                                sc.SetState(SCE_OSCRIPT_SINGLEQUOTE_STRING);
                        } else if (sc.Match('\"')) {
                                sc.SetState(SCE_OSCRIPT_DOUBLEQUOTE_STRING);
                        } else if (sc.Match('/', '/')) {
                                sc.SetState(SCE_OSCRIPT_LINE_COMMENT);
                                sc.Forward();
                        } else if (sc.Match('/', '*')) {
                                sc.SetState(SCE_OSCRIPT_BLOCK_COMMENT);
                                sc.Forward();
                        } else if (isFirstToken && sc.Match('#')) {
                                sc.SetState(SCE_OSCRIPT_PREPROCESSOR);
                        } else if (sc.Match('$')) {
                                // Both process-global ($xxx) and thread-global ($$xxx)
                                // variables are handled as one global.
                                sc.SetState(SCE_OSCRIPT_GLOBAL);
                        } else if (IsNaturalNumberStart(sc.ch)) {
                                sc.SetState(SCE_OSCRIPT_NUMBER);
                        } else if (IsPrefixedNumberStart(sc.ch, sc.chNext)) {
                                sc.SetState(SCE_OSCRIPT_NUMBER);
                                sc.Forward();
                        } else if (sc.Match('.') && IsIdentifierStart(sc.chNext)) {
                                // Every object member access is marked as a property access
                                // initially. The decision between property and method is made
                                // after parsing the identifier and looking what comes then.
                                // KNOWN PROBLEM: If there is whitespace between the following
                                // identifier and the dot, the dot will not be recognized
                                // as a member accessing operator. In turn, the identifier
                                // will not be recognizable as a property or a method too.
                                sc.SetState(SCE_OSCRIPT_OPERATOR);
                                sc.Forward();
                                sc.SetState(SCE_OSCRIPT_PROPERTY);
                        } else if (IsIdentifierStart(sc.ch)) {
                                sc.SetState(SCE_OSCRIPT_IDENTIFIER);
                        } else if (IsOperator(sc.ch)) {
                                sc.SetState(SCE_OSCRIPT_OPERATOR);
                        }
                }

                if (isFirstToken && !IsASpaceOrTab(sc.ch)) {
                        isFirstToken = false;
                }
        }

        sc.Complete();
}

// ------------------------------------------
// Functions supporting OScript code folding.

static inline bool IsBlockComment(int style) {
        return style == SCE_OSCRIPT_BLOCK_COMMENT;
}

static bool IsLineComment(int line, Accessor &styler) {
        int pos = styler.LineStart(line);
        int eolPos = styler.LineStart(line + 1) - 1;
        for (int i = pos; i < eolPos; i++) {
                char ch = styler[i];
                char chNext = styler.SafeGetCharAt(i + 1);
                int style = styler.StyleAt(i);
                if (ch == '/' && chNext == '/' && style == SCE_OSCRIPT_LINE_COMMENT) {
                        return true;
                } else if (!IsASpaceOrTab(ch)) {
                        return false;
                }
        }
        return false;
}

static inline bool IsPreprocessor(int style) {
        return style == SCE_OSCRIPT_PREPROCESSOR ||
                   style == SCE_OSCRIPT_DOC_COMMENT;
}

static void GetRangeLowered(unsigned int start, unsigned int end,
                                                        Accessor &styler, char *s, unsigned int len) {
        unsigned int i = 0;
        while (i < end - start + 1 && i < len - 1) {
                s[i] = static_cast<char>(tolower(styler[start + i]));
                i++;
        }
        s[i] = '\0';
}

static void GetForwardWordLowered(unsigned int start, Accessor &styler,
                                                                  char *s, unsigned int len) {
        unsigned int i = 0;
        while (i < len - 1 && IsAlpha(styler.SafeGetCharAt(start + i))) {
                s[i] = static_cast<char>(tolower(styler.SafeGetCharAt(start + i)));
                i++;
        }
        s[i] = '\0';
}

static void UpdatePreprocessorFoldLevel(int &levelCurrent,
                unsigned int startPos, Accessor &styler) {
        char s[7]; // Size of the longest possible keyword + null.
        GetForwardWordLowered(startPos, styler, s, sizeof(s));

        if (strcmp(s, "ifdef") == 0 ||
                strcmp(s, "ifndef") == 0) {
                levelCurrent++;
        } else if (strcmp(s, "endif") == 0) {
                levelCurrent--;
                if (levelCurrent < SC_FOLDLEVELBASE) {
                        levelCurrent = SC_FOLDLEVELBASE;
                }
        }
}

static void UpdateKeywordFoldLevel(int &levelCurrent, unsigned int lastStart,
                unsigned int currentPos, Accessor &styler) {
        char s[9];
        GetRangeLowered(lastStart, currentPos, styler, s, sizeof(s));

        if (strcmp(s, "if") == 0 || strcmp(s, "for") == 0 ||
                strcmp(s, "switch") == 0 || strcmp(s, "function") == 0 ||
                strcmp(s, "while") == 0 || strcmp(s, "repeat") == 0) {
                levelCurrent++;
        } else if (strcmp(s, "end") == 0 || strcmp(s, "until") == 0) {
                levelCurrent--;
                if (levelCurrent < SC_FOLDLEVELBASE) {
                        levelCurrent = SC_FOLDLEVELBASE;
                }
        }
}

// ------------------------------
// Function folding OScript code.

static void FoldOScriptDoc(unsigned int startPos, int length, int initStyle,
                                                   WordList *[], Accessor &styler) {
        bool foldComment = styler.GetPropertyInt("fold.comment") != 0;
        bool foldPreprocessor = styler.GetPropertyInt("fold.preprocessor") != 0;
        bool foldCompact = styler.GetPropertyInt("fold.compact", 1) != 0;
        int endPos = startPos + length;
        int visibleChars = 0;
        int lineCurrent = styler.GetLine(startPos);
        int levelPrev = styler.LevelAt(lineCurrent) & SC_FOLDLEVELNUMBERMASK;
        int levelCurrent = levelPrev;
        char chNext = styler[startPos];
        int styleNext = styler.StyleAt(startPos);
        int style = initStyle;
        int lastStart = 0;

        for (int i = startPos; i < endPos; i++) {
                char ch = chNext;
                chNext = styler.SafeGetCharAt(i + 1);
                int stylePrev = style;
                style = styleNext;
                styleNext = styler.StyleAt(i + 1);
                bool atLineEnd = (ch == '\r' && chNext != '\n') || (ch == '\n');

                if (foldComment && IsBlockComment(style)) {
                        if (!IsBlockComment(stylePrev)) {
                                levelCurrent++;
                        } else if (!IsBlockComment(styleNext) && !atLineEnd) {
                                // Comments do not end at end of line and the next character
                                // may not be styled.
                                levelCurrent--;
                        }
                }
                if (foldComment && atLineEnd && IsLineComment(lineCurrent, styler)) {
                        if (!IsLineComment(lineCurrent - 1, styler) &&
                                IsLineComment(lineCurrent + 1, styler))
                                levelCurrent++;
                        else if (IsLineComment(lineCurrent - 1, styler) &&
                                         !IsLineComment(lineCurrent+1, styler))
                                levelCurrent--;
                }
                if (foldPreprocessor) {
                        if (ch == '#' && IsPreprocessor(style)) {
                                UpdatePreprocessorFoldLevel(levelCurrent, i + 1, styler);
                        }
                }

                if (stylePrev != SCE_OSCRIPT_KEYWORD && style == SCE_OSCRIPT_KEYWORD) {
                        lastStart = i;
                }
                if (stylePrev == SCE_OSCRIPT_KEYWORD) {
                        if(IsIdentifierChar(ch) && !IsIdentifierChar(chNext)) {
                                UpdateKeywordFoldLevel(levelCurrent, lastStart, i, styler);
                        }
                }

                if (!IsASpace(ch))
                        visibleChars++;

                if (atLineEnd) {
                        int level = levelPrev;
                        if (visibleChars == 0 && foldCompact)
                                level |= SC_FOLDLEVELWHITEFLAG;
                        if ((levelCurrent > levelPrev) && (visibleChars > 0))
                                level |= SC_FOLDLEVELHEADERFLAG;
                        if (level != styler.LevelAt(lineCurrent)) {
                                styler.SetLevel(lineCurrent, level);
                        }
                        lineCurrent++;
                        levelPrev = levelCurrent;
                        visibleChars = 0;
                }
        }

        // If we did not reach EOLN in the previous loop, store the line level and
        // whitespace information. The rest will be filled in later.
        int lev = levelPrev;
        if (visibleChars == 0 && foldCompact)
                lev |= SC_FOLDLEVELWHITEFLAG;
        styler.SetLevel(lineCurrent, lev);
}

// --------------------------------------------
// Declaration of the OScript lexer descriptor.

static const char * const oscriptWordListDesc[] = {
        "Keywords and reserved words",
        "Literal constants",
        "Literal operators",
        "Built-in value and reference types",
        "Built-in global functions",
        "Built-in static objects",
        0
};

LexerModule lmOScript(SCLEX_OSCRIPT, ColouriseOScriptDoc, "oscript", FoldOScriptDoc, oscriptWordListDesc);