uax 9

System Information

Definition Index

• ORG.SHIRAKUMO.ALLOY.UAX-9

  No documentation provided.

  • EXTERNAL SPECIAL-VARIABLE

    *BIDI-BRACKETS-TABLE-FILE*

    Variable containing the absolute path of the brackets table file.
    
    See LOAD-DATABASES
    See COMPILE-DATABASES

  • EXTERNAL SPECIAL-VARIABLE

    *BIDI-CLASS-DATABASE-FILE*

    Variable containing the absolute path of the bidi class database file.
    
    See LOAD-DATABASES
    See COMPILE-DATABASES

  • EXTERNAL SPECIAL-VARIABLE

    *BIDI-MIRRORING-TABLE-FILE*

    Variable containing the absolute path of the mirroring table file.
    
    See LOAD-DATABASES
    See COMPILE-DATABASES

  • EXTERNAL CONDITION

    NO-DATABASE-FILES

    Warning signalled when LOAD-DATABASES is called and the files are not present.
    
    Two restarts must be active when this condition is signalled:
    
      COMPILE --- Call COMPILE-DATABASES
      ABORT   --- Abort loading the databases, leaving them at their
                  previous state.
    
    See LOAD-DATABASES

  • EXTERNAL FUNCTION

    CALL-IN-ORDER

    • FUNCTION
    • STRING
    • &OPTIONAL
    • LEVELS
    • INDEXES

    Source

    Calls the function per character in proper order over the string.
    
    The function must accept two arguments:
    
      CHARACTER     --- The character to display.
      MANUAL-MIRROR --- Whether the rendering engine should draw the
                        character mirrored.
    
    This function will iterate over the string in the proper order to
    respect bidirectionality.
    
    If indexes is not passed, it is automatically computed through REORDER
    on the levels. If levels is not passed, it is automatically computed
    through LEVELS on the string.
    
    Note that the CHARACTER passed to the function is already mirrored if
    a mirrored character exists in unicode. This means you do not need to
    call MIRROR-AT yourself.
    
    See LEVELS
    See REORDER
    See MIRROR-AT
    See DO-IN-ORDER

  • EXTERNAL FUNCTION

    COMPILE-DATABASES

    Compiles the database files from their sources.
    
    This will load an optional part of the system and compile the database
    files to an efficient byte representation. If the compilation is
    successful, LOAD-DATABASES is called automatically.
    
    See *BIDI-CLASS-DATABASE-FILE*
    See *BIDI-BRACKETS-TABLE-FILE*
    See *BIDI-CLASS-DATABASE-FILE*
    See LOAD-DATABASES

  • EXTERNAL FUNCTION

    LEVELS

    • STRING
    • &KEY
    • BASE-DIRECTION
    • LINE-BREAKS
    • START
    • END

    Source

    Computes the directional level for every code point in the string.
    
    Returns two values:
    
      LEVELS         --- A vector of levels for each code point in the
                         input string. Has the length of the input
                         string.
      BASE-DIRECTION --- Returns the base direction of the string. If
                         BASE-DIRECTION was not :AUTO, this is the
                         determined direction.
    
    BASE-DIRECTION must be one of three values:
    
      :LEFT-TO-RIGHT
      :RIGHT-TO-LEFT
      :AUTO (default)
    
    This designates how the text is interpreted at its base level. When
    this level is :AUTO, the base level is determined automatically by
    scanning for the first directional code point in the string.
    
    LINE-BREAKS should be a list of indexes into the string. Each index
    designates a code point after which a line break is inserted. This is
    used to normalise the levels across breaks. If you pass this argument,
    you must pass the same argument to REORDER. If you do not pass this,
    the line end is assumed to be at the end of the string.
    
    The values in the levels vector designate which direction the code
    point at this index should have. If the level is even, the direction
    is LEFT-TO-RIGHT; if it is odd, RIGHT-TO-LEFT. You will need this
    information yourself to determine whether to display code points
    mirrored or not when rendering their glyphs.
    
    See REORDER
    See MIRROR-AT

  • EXTERNAL FUNCTION

    LOAD-DATABASES

    Loads the databases from their files into memory.
    
    If one of the files is missing, a warning of type NO-DATABASE-FILES is
    signalled. If the loading succeeds, T is returned.
    
    See *BIDI-CLASS-DATABASE-FILE*
    See *BIDI-BRACKETS-TABLE-FILE*
    See *BIDI-CLASS-DATABASE-FILE*
    See NO-DATABASE-FILES

  • EXTERNAL FUNCTION

    MIRROR-AT

    • STRING
    • I

    Returns the mirrored character at the given position in the string.
    
    Returns two values:
    
      CHARACTER      --- The character to display. This may either be same
                         character as was passed in, or its mirror sibling.
      MANUAL-MIRROR  --- Whether the character needs to be displayed in a
                         mirrored way in the renderer.
    
    If MANUAL-MIRROR is T, the returned character will be the same as the
    character at that point in the string. The rendering engine displaying
    the character must ensure that it is drawn mirrored instead.
    
    If MANUAL-MIRROR is NIL, the returned character can be drawn in all
    cases to achieve the correct mirroring behaviour.
    
    Note that you should only invoke this function to retrieve the mirror
    pair if the level of the character at the point is uneven and thus
    right-to-left.

  • EXTERNAL FUNCTION

    REORDER

    • LEVELS
    • &KEY
    • LINE-BREAKS
    • INDEXES

    Source

    Computes a reordering of indexes into the string to process the code points in the correct order.
    
    Returns one value, the reordered index vector, the same length as the
    input LEVELS vector. The vector should be filled with indices into the
    original string. Iterating through this index vector in order should
    provide the correct ordering for the resulting code points when
    rendering along the base direction.
    
    LINE-BREAKS should be a list of indexes into the string. Each index
    designates a code point after which a line break is inserted. This
    argument must be the same as what you passed to LEVELS to get the
    levels vector.
    
    INDEXES is the index vector that's permuted and returned. You can pass
    this to save on allocation. If not passed, a vector the length of the
    levels vector is created. If passed, you should make sure that the
    indices in the vector make sense -- meaning they should typically be
    in ascending order starting with 0.
    
    See LEVELS

  • EXTERNAL MACRO

    DO-IN-ORDER

    • CHARACTER
    • MANUAL-MIRROR
    • STRING
    • &OPTIONAL
    • LEVELS
    • INDEXES
    • &BODY
    • BODY

    Source

    Iterates over the string in bidirectional order, binding CHARACTER and MANUAL-MIRROR for each character.
    
    This is a convenience macro around CALL-IN-ORDER.
    
    See CALL-IN-ORDER