Parse.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "Containers/StringFwd.h"
#include "Containers/UnrealString.h"
#include "CoreTypes.h"
#include "HAL/PlatformCrt.h"
#include "Misc/Build.h"
#include "Misc/EnumClassFlags.h"
#include "Templates/Function.h"
 
class FExec;
class FName;
class FOutputDevice;
class FText;
 
/*-----------------------------------------------------------------------------
    Parsing functions.
-----------------------------------------------------------------------------*/
struct FParse
{
    static CORE_API bool Command( const TCHAR** Stream, const TCHAR* Match, bool bParseMightTriggerExecution = true );
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, FName& Name );
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, uint32& Value );
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, struct FGuid& Guid );
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, TCHAR* Value, int32 MaxLen, bool bShouldStopOnSeparator=true, const TCHAR** OptStreamGotTo = nullptr);
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, uint8& Value );
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, int8& Value );
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, uint16& Value );
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, int16& Value );
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, float& Value );
    static CORE_API bool Value(const TCHAR* Stream, const TCHAR* Match, double& Value);
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, int32& Value );
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, FString& Value, bool bShouldStopOnSeparator =true, const TCHAR** OptStreamGotTo = nullptr);
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, FText& Value, const TCHAR* Namespace = NULL );
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, uint64& Value );
    static CORE_API bool Value( const TCHAR* Stream, const TCHAR* Match, int64& Value );
    static CORE_API bool Bool( const TCHAR* Stream, const TCHAR* Match, bool& OnOff );
    static CORE_API bool Line( const TCHAR** Stream, TCHAR* Result, int32 MaxLen, bool Exact= false );
    static CORE_API bool Line( const TCHAR** Stream, FString& Result, bool Exact = false );
    static CORE_API bool Line( const TCHAR** Stream, FStringView& Result, bool Exact = false );
    enum class ELineExtendedFlags : uint8
    {
        None = 0,
        SwallowDoubleSlashComments = 1,
        SwallowSemicolonComments = 2,
        SwallowExtraEOLs = 4,
        BreakOnPipe = 8,
        AllowBracketedMultiline = 16, // if a EOL happens between {} curly brackets, insert a space, and continue parsing the next line
        AllowEscapedEOLMultiline = 32, // if a EOL happens right after a \ backslash, insert a space, and continue parsing the next line
        
        // Standard maps to an "expected" set of flags (<eol> is replaced with space, no comments, don't swallow extra EOLs, no { } processing)
        Standard = AllowEscapedEOLMultiline,
 
        // OldDefaultMode maps to what the previous 'bExact' mapped to when false
        OldDefaultMode = SwallowDoubleSlashComments | BreakOnPipe | AllowBracketedMultiline | AllowEscapedEOLMultiline | SwallowExtraEOLs,
        // OldExactMode maps to what the previous 'bExact' mapped to when true
        OldExactMode = AllowBracketedMultiline | AllowEscapedEOLMultiline,
    };
 
    static CORE_API bool LineExtended(const TCHAR** Stream, FString& Result, int32& LinesConsumed, ELineExtendedFlags Flags = ELineExtendedFlags::Standard);
    static CORE_API bool LineExtended(const TCHAR** Stream, FStringBuilderBase& Result, int32& LinesConsumed, ELineExtendedFlags Flags = ELineExtendedFlags::Standard);
    UE_DEPRECATED(5.6, "Use the version that takes ELineExtendedFlags")
    static bool LineExtended(const TCHAR** Stream, FString& Result, int32& LinesConsumed, bool bExact)
    {
        return LineExtended(Stream, Result, LinesConsumed, (bExact ? ELineExtendedFlags::OldExactMode : ELineExtendedFlags::OldDefaultMode));
    }
    UE_DEPRECATED(5.6, "Use the version that takes ELineExtendedFlags")
    static bool LineExtended(const TCHAR** Stream, FStringBuilderBase& Result, int32& LinesConsumed, bool bExact)
    {
        return LineExtended(Stream, Result, LinesConsumed, (bExact ? ELineExtendedFlags::OldExactMode : ELineExtendedFlags::OldDefaultMode));
    }
    static CORE_API bool Token( const TCHAR*& Str, TCHAR* Result, int32 MaxLen, bool bUseEscape, const TCHAR SingleCharacterDelimiter = TEXT('\0'));
    static CORE_API bool Token( const TCHAR*& Str, FString& Arg, bool bUseEscape, const TCHAR SingleCharacterDelimiter = TEXT('\0'));
    static CORE_API bool AlnumToken(const TCHAR*& Str, FString& Arg);
    static CORE_API FString Token( const TCHAR*& Str, bool UseEscape );
    static CORE_API void Next( const TCHAR** Stream );
    static CORE_API bool Param( const TCHAR* Stream, const TCHAR* Param );
    static CORE_API bool Text( const TCHAR* Stream, FText& Value, const TCHAR* Namespace = nullptr );
    static CORE_API bool QuotedString( const TCHAR* Stream, FString& Value, int32* OutNumCharsRead = nullptr );
    static CORE_API bool QuotedString( const TCHAR* Stream, FStringBuilderBase& Value, int32* OutNumCharsRead = nullptr );
    static CORE_API bool Expression(const TCHAR*& Str, FString& OutExpression, bool bUseEscape, const TCHAR SingleCharacterDelimiter = TEXT('\0'));
 
    //
    // Parse a hex digit.
    //
    static inline int32 HexDigit(TCHAR c)
    {
        int32 Result = 0;
 
        if (c >= '0' && c <= '9')
        {
            Result = c - '0';
        }
        else if (c >= 'a' && c <= 'f')
        {
            Result = c + 10 - 'a';
        }
        else if (c >= 'A' && c <= 'F')
        {
            Result = c + 10 - 'A';
        }
        else
        {
            Result = 0;
        }
 
        return Result;
    }
 
    static CORE_API uint32 HexNumber(FStringView HexString);
    static CORE_API uint64 HexNumber64(FStringView HexString);
 
    static CORE_API bool SchemeNameFromURI(const TCHAR* InURI, FString& OutSchemeName);
 
 
    //
    // CLI string parsing using grammar based parser.
    //
 
    enum class EGrammarBasedParseFlags
    {
        None                = 0u,
        AllowQuotedCommands = 1 << 0u,
    };
 
    enum class EGrammarBasedParseErrorCode
    {
        Succeeded,
        NotRun,
        UnBalancedQuote,
        DisallowedQuotedCommand
    };
 
    struct FGrammarBasedParseResult
    {
        const TCHAR* At = nullptr;
        EGrammarBasedParseErrorCode ErrorCode = EGrammarBasedParseErrorCode::NotRun;
    };
 
    static CORE_API FGrammarBasedParseResult GrammarBasedCLIParse(const TCHAR* Stream, TFunctionRef<void(FStringView, FStringView)> OnCommandCallback, EGrammarBasedParseFlags Flags = EGrammarBasedParseFlags::AllowQuotedCommands);
};
 
ENUM_CLASS_FLAGS(FParse::EGrammarBasedParseFlags);
ENUM_CLASS_FLAGS(FParse::ELineExtendedFlags)
 
#if !UE_BUILD_SHIPPING
 
UE_DEPRECATED("5.6", "Use the overload that takes the entire command instead of a pattern.")
CORE_API bool ConsoleCommandLibrary_DumpLibrary(class UWorld* InWorld, FExec& SubSystem, const FString& Cmd, FOutputDevice& Ar);
 
CORE_API bool ConsoleCommandLibrary_DumpLibrary(class UWorld* InWorld, FExec& SubSystem, const TCHAR* Cmd, FOutputDevice& Ar);
 
CORE_API bool ConsoleCommandLibrary_DumpLibraryHTML(class UWorld* InWorld, FExec& SubSystem, const FString& OutPath);
#endif // !UE_BUILD_SHIPPING