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Annotation of mandoc/mandoc.3, Revision 1.15

1.15    ! kristaps    1: .\"    $Id: mandoc.3,v 1.14 2011/10/06 22:29:12 kristaps Exp $
1.1       kristaps    2: .\"
                      3: .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
                      4: .\" Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
                      5: .\"
                      6: .\" Permission to use, copy, modify, and distribute this software for any
                      7: .\" purpose with or without fee is hereby granted, provided that the above
                      8: .\" copyright notice and this permission notice appear in all copies.
                      9: .\"
                     10: .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
                     11: .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
                     12: .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
                     13: .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
                     14: .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
                     15: .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
                     16: .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
                     17: .\"
1.15    ! kristaps   18: .Dd $Mdocdate: October 6 2011 $
1.1       kristaps   19: .Dt MANDOC 3
                     20: .Os
                     21: .Sh NAME
                     22: .Nm mandoc ,
1.3       kristaps   23: .Nm mandoc_escape ,
1.1       kristaps   24: .Nm man_meta ,
1.14      kristaps   25: .Nm man_mparse ,
1.1       kristaps   26: .Nm man_node ,
1.6       kristaps   27: .Nm mchars_alloc ,
                     28: .Nm mchars_free ,
                     29: .Nm mchars_num2char ,
1.7       kristaps   30: .Nm mchars_num2uc ,
1.6       kristaps   31: .Nm mchars_spec2cp ,
                     32: .Nm mchars_spec2str ,
1.1       kristaps   33: .Nm mdoc_meta ,
                     34: .Nm mdoc_node ,
                     35: .Nm mparse_alloc ,
                     36: .Nm mparse_free ,
1.14      kristaps   37: .Nm mparse_getkeep ,
                     38: .Nm mparse_keep ,
1.1       kristaps   39: .Nm mparse_readfd ,
                     40: .Nm mparse_reset ,
1.2       kristaps   41: .Nm mparse_result ,
                     42: .Nm mparse_strerror ,
                     43: .Nm mparse_strlevel
1.1       kristaps   44: .Nd mandoc macro compiler library
1.8       kristaps   45: .Sh LIBRARY
                     46: .Lb mandoc
1.1       kristaps   47: .Sh SYNOPSIS
                     48: .In man.h
                     49: .In mdoc.h
                     50: .In mandoc.h
1.3       kristaps   51: .Ft "enum mandoc_esc"
                     52: .Fo mandoc_escape
1.15    ! kristaps   53: .Fa "const char **end"
        !            54: .Fa "const char **start"
        !            55: .Fa "int *sz"
1.3       kristaps   56: .Fc
1.1       kristaps   57: .Ft "const struct man_meta *"
                     58: .Fo man_meta
                     59: .Fa "const struct man *man"
                     60: .Fc
1.14      kristaps   61: .Ft "const struct mparse *"
                     62: .Fo man_mparse
                     63: .Fa "const struct man *man"
                     64: .Fc
1.1       kristaps   65: .Ft "const struct man_node *"
                     66: .Fo man_node
                     67: .Fa "const struct man *man"
                     68: .Fc
1.6       kristaps   69: .Ft "struct mchars *"
                     70: .Fn mchars_alloc
                     71: .Ft void
                     72: .Fn mchars_free "struct mchars *p"
                     73: .Ft char
                     74: .Fn mchars_num2char "const char *cp" "size_t sz"
1.7       kristaps   75: .Ft int
                     76: .Fn mchars_num2uc "const char *cp" "size_t sz"
1.6       kristaps   77: .Ft "const char *"
                     78: .Fo mchars_spec2str
                     79: .Fa "struct mchars *p"
                     80: .Fa "const char *cp"
                     81: .Fa "size_t sz"
                     82: .Fa "size_t *rsz"
                     83: .Fc
                     84: .Ft int
                     85: .Fo mchars_spec2cp
                     86: .Fa "struct mchars *p"
                     87: .Fa "const char *cp"
                     88: .Fa "size_t sz"
                     89: .Ft "const char *"
                     90: .Fc
1.1       kristaps   91: .Ft "const struct mdoc_meta *"
                     92: .Fo mdoc_meta
                     93: .Fa "const struct mdoc *mdoc"
                     94: .Fc
                     95: .Ft "const struct mdoc_node *"
                     96: .Fo mdoc_node
                     97: .Fa "const struct mdoc *mdoc"
                     98: .Fc
                     99: .Ft void
                    100: .Fo mparse_alloc
                    101: .Fa "enum mparset type"
                    102: .Fa "enum mandoclevel wlevel"
                    103: .Fa "mandocmsg msg"
                    104: .Fa "void *msgarg"
                    105: .Fc
                    106: .Ft void
                    107: .Fo mparse_free
                    108: .Fa "struct mparse *parse"
                    109: .Fc
1.14      kristaps  110: .Ft void
                    111: .Fo mparse_getkeep
                    112: .Fa "const struct mparse *parse"
                    113: .Fc
                    114: .Ft void
                    115: .Fo mparse_keep
                    116: .Fa "struct mparse *parse"
                    117: .Fc
1.1       kristaps  118: .Ft "enum mandoclevel"
                    119: .Fo mparse_readfd
                    120: .Fa "struct mparse *parse"
                    121: .Fa "int fd"
                    122: .Fa "const char *fname"
                    123: .Fc
                    124: .Ft void
                    125: .Fo mparse_reset
                    126: .Fa "struct mparse *parse"
                    127: .Fc
                    128: .Ft void
                    129: .Fo mparse_result
                    130: .Fa "struct mparse *parse"
                    131: .Fa "struct mdoc **mdoc"
                    132: .Fa "struct man **man"
1.2       kristaps  133: .Fc
                    134: .Ft "const char *"
                    135: .Fo mparse_strerror
                    136: .Fa "enum mandocerr"
                    137: .Fc
                    138: .Ft "const char *"
                    139: .Fo mparse_strlevel
                    140: .Fa "enum mandoclevel"
1.1       kristaps  141: .Fc
                    142: .Vt extern const char * const * man_macronames;
                    143: .Vt extern const char * const * mdoc_argnames;
                    144: .Vt extern const char * const * mdoc_macronames;
1.4       kristaps  145: .Fd "#define ASCII_NBRSP"
                    146: .Fd "#define ASCII_HYPH"
1.1       kristaps  147: .Sh DESCRIPTION
                    148: The
                    149: .Nm mandoc
                    150: library parses a
                    151: .Ux
                    152: manual into an abstract syntax tree (AST).
                    153: .Ux
                    154: manuals are composed of
                    155: .Xr mdoc 7
                    156: or
                    157: .Xr man 7 ,
                    158: and may be mixed with
                    159: .Xr roff 7 ,
                    160: .Xr tbl 7 ,
                    161: and
                    162: .Xr eqn 7
                    163: invocations.
                    164: .Pp
                    165: The following describes a general parse sequence:
                    166: .Bl -enum
                    167: .It
                    168: initiate a parsing sequence with
                    169: .Fn mparse_alloc ;
                    170: .It
                    171: parse files or file descriptors with
                    172: .Fn mparse_readfd ;
                    173: .It
                    174: retrieve a parsed syntax tree, if the parse was successful, with
                    175: .Fn mparse_result ;
                    176: .It
                    177: iterate over parse nodes with
                    178: .Fn mdoc_node
                    179: or
                    180: .Fn man_node ;
                    181: .It
                    182: free all allocated memory with
                    183: .Fn mparse_free ,
                    184: or invoke
                    185: .Fn mparse_reset
                    186: and parse new files.
1.3       kristaps  187: .El
1.6       kristaps  188: .Pp
                    189: The
                    190: .Nm
                    191: library also contains routines for translating character strings into glyphs
                    192: .Pq see Fn mchars_alloc
                    193: and parsing escape sequences from strings
                    194: .Pq see Fn mandoc_escape .
1.3       kristaps  195: .Sh REFERENCE
                    196: This section documents the functions, types, and variables available
                    197: via
                    198: .In mandoc.h .
                    199: .Ss Types
                    200: .Bl -ohang
                    201: .It Vt "enum mandoc_esc"
1.11      kristaps  202: An escape sequence classification.
1.3       kristaps  203: .It Vt "enum mandocerr"
1.11      kristaps  204: A fatal error, error, or warning message during parsing.
1.3       kristaps  205: .It Vt "enum mandoclevel"
1.11      kristaps  206: A classification of an
                    207: .Vt "enum mandoclevel"
                    208: as regards system operation.
1.6       kristaps  209: .It Vt "struct mchars"
                    210: An opaque pointer to an object allowing for translation between
                    211: character strings and glyphs.
                    212: See
                    213: .Fn mchars_alloc .
1.3       kristaps  214: .It Vt "enum mparset"
1.11      kristaps  215: The type of parser when reading input.
                    216: This should usually be
1.12      kristaps  217: .Dv MPARSE_AUTO
1.11      kristaps  218: for auto-detection.
1.3       kristaps  219: .It Vt "struct mparse"
1.11      kristaps  220: An opaque pointer to a running parse sequence.
                    221: Created with
                    222: .Fn mparse_alloc
                    223: and freed with
                    224: .Fn mparse_free .
                    225: This may be used across parsed input if
                    226: .Fn mparse_reset
                    227: is called between parses.
1.3       kristaps  228: .It Vt "mandocmsg"
1.11      kristaps  229: A prototype for a function to handle fatal error, error, and warning
                    230: messages emitted by the parser.
1.3       kristaps  231: .El
                    232: .Ss Functions
                    233: .Bl -ohang
                    234: .It Fn mandoc_escape
1.4       kristaps  235: Scan an escape sequence, i.e., a character string beginning with
                    236: .Sq \e .
                    237: Pass a pointer to this string as
                    238: .Va end ;
                    239: it will be set to the supremum of the parsed escape sequence unless
1.12      kristaps  240: returning
                    241: .Dv ESCAPE_ERROR ,
                    242: in which case the string is bogus and should be
1.4       kristaps  243: thrown away.
1.12      kristaps  244: If not
                    245: .Dv ESCAPE_ERROR
                    246: or
                    247: .Dv ESCAPE_IGNORE ,
1.4       kristaps  248: .Va start
                    249: is set to the first relevant character of the substring (font, glyph,
                    250: whatever) of length
                    251: .Va sz .
                    252: Both
                    253: .Va start
                    254: and
                    255: .Va sz
1.12      kristaps  256: may be
                    257: .Dv NULL .
1.3       kristaps  258: .It Fn man_meta
1.4       kristaps  259: Obtain the meta-data of a successful parse.
                    260: This may only be used on a pointer returned by
                    261: .Fn mparse_result .
1.14      kristaps  262: .It Fn man_mparse
                    263: Get the parser used for the current output.
1.3       kristaps  264: .It Fn man_node
1.4       kristaps  265: Obtain the root node of a successful parse.
                    266: This may only be used on a pointer returned by
                    267: .Fn mparse_result .
1.6       kristaps  268: .It Fn mchars_alloc
                    269: Allocate an
                    270: .Vt "struct mchars *"
                    271: object for translating special characters into glyphs.
                    272: See
                    273: .Xr mandoc_char 7
                    274: for an overview of special characters.
                    275: The object must be freed with
                    276: .Fn mchars_free .
                    277: .It Fn mchars_free
                    278: Free an object created with
                    279: .Fn mchars_alloc .
                    280: .It Fn mchars_num2char
1.7       kristaps  281: Convert a character index (e.g., the \eN\(aq\(aq escape) into a
                    282: printable ASCII character.
                    283: Returns \e0 (the nil character) if the input sequence is malformed.
                    284: .It Fn mchars_num2uc
                    285: Convert a hexadecimal character index (e.g., the \e[uNNNN] escape) into
                    286: a Unicode codepoint.
1.6       kristaps  287: Returns \e0 (the nil character) if the input sequence is malformed.
                    288: .It Fn mchars_spec2cp
                    289: Convert a special character into a valid Unicode codepoint.
1.10      kristaps  290: Returns \-1 on failure or a non-zero Unicode codepoint on success.
1.6       kristaps  291: .It Fn mchars_spec2str
                    292: Convert a special character into an ASCII string.
1.12      kristaps  293: Returns
                    294: .Dv NULL
                    295: on failure.
1.3       kristaps  296: .It Fn mdoc_meta
1.4       kristaps  297: Obtain the meta-data of a successful parse.
                    298: This may only be used on a pointer returned by
                    299: .Fn mparse_result .
1.3       kristaps  300: .It Fn mdoc_node
1.4       kristaps  301: Obtain the root node of a successful parse.
                    302: This may only be used on a pointer returned by
                    303: .Fn mparse_result .
1.3       kristaps  304: .It Fn mparse_alloc
1.4       kristaps  305: Allocate a parser.
                    306: The same parser may be used for multiple files so long as
                    307: .Fn mparse_reset
                    308: is called between parses.
                    309: .Fn mparse_free
                    310: must be called to free the memory allocated by this function.
1.3       kristaps  311: .It Fn mparse_free
1.4       kristaps  312: Free all memory allocated by
                    313: .Fn mparse_alloc .
1.14      kristaps  314: .It Fn mparse_getkeep
                    315: Acquire the keep buffer.
                    316: Must follow a call of
                    317: .Fn mparse_keep .
                    318: .It Fn mparse_keep
                    319: Instruct the parser to retain a copy of its parsed input.
                    320: This can be acquired with subsequent
                    321: .Fn mparse_getkeep
                    322: calls.
1.3       kristaps  323: .It Fn mparse_readfd
1.4       kristaps  324: Parse a file or file descriptor.
                    325: If
                    326: .Va fd
                    327: is -1,
                    328: .Va fname
                    329: is opened for reading.
                    330: Otherwise,
                    331: .Va fname
                    332: is assumed to be the name associated with
                    333: .Va fd .
                    334: This may be called multiple times with different parameters; however,
                    335: .Fn mparse_reset
                    336: should be invoked between parses.
1.3       kristaps  337: .It Fn mparse_reset
1.4       kristaps  338: Reset a parser so that
                    339: .Fn mparse_readfd
                    340: may be used again.
1.3       kristaps  341: .It Fn mparse_result
1.4       kristaps  342: Obtain the result of a parse.
                    343: Only successful parses
                    344: .Po
                    345: i.e., those where
                    346: .Fn mparse_readfd
                    347: returned less than MANDOCLEVEL_FATAL
                    348: .Pc
                    349: should invoke this function, in which case one of the two pointers will
                    350: be filled in.
1.3       kristaps  351: .It Fn mparse_strerror
1.4       kristaps  352: Return a statically-allocated string representation of an error code.
1.3       kristaps  353: .It Fn mparse_strlevel
1.4       kristaps  354: Return a statically-allocated string representation of a level code.
1.3       kristaps  355: .El
                    356: .Ss Variables
                    357: .Bl -ohang
                    358: .It Va man_macronames
1.4       kristaps  359: The string representation of a man macro as indexed by
                    360: .Vt "enum mant" .
1.3       kristaps  361: .It Va mdoc_argnames
1.4       kristaps  362: The string representation of a mdoc macro argument as indexed by
                    363: .Vt "enum mdocargt" .
1.3       kristaps  364: .It Va mdoc_macronames
1.4       kristaps  365: The string representation of a mdoc macro as indexed by
                    366: .Vt "enum mdoct" .
1.1       kristaps  367: .El
                    368: .Sh IMPLEMENTATION NOTES
                    369: This section consists of structural documentation for
                    370: .Xr mdoc 7
                    371: and
                    372: .Xr man 7
1.11      kristaps  373: syntax trees and strings.
                    374: .Ss Man and Mdoc Strings
                    375: Strings may be extracted from mdoc and man meta-data, or from text
                    376: nodes (MDOC_TEXT and MAN_TEXT, respectively).
                    377: These strings have special non-printing formatting cues embedded in the
                    378: text itself, as well as
                    379: .Xr roff 7
                    380: escapes preserved from input.
                    381: Implementing systems will need to handle both situations to produce
                    382: human-readable text.
                    383: In general, strings may be assumed to consist of 7-bit ASCII characters.
                    384: .Pp
                    385: The following non-printing characters may be embedded in text strings:
                    386: .Bl -tag -width Ds
                    387: .It Dv ASCII_NBRSP
                    388: A non-breaking space character.
                    389: .It Dv ASCII_HYPH
                    390: A soft hyphen.
                    391: .El
                    392: .Pp
                    393: Escape characters are also passed verbatim into text strings.
                    394: An escape character is a sequence of characters beginning with the
                    395: backslash
                    396: .Pq Sq \e .
                    397: To construct human-readable text, these should be intercepted with
                    398: .Fn mandoc_escape
                    399: and converted with one of
                    400: .Fn mchars_num2char ,
                    401: .Fn mchars_spec2str ,
                    402: and so on.
1.1       kristaps  403: .Ss Man Abstract Syntax Tree
                    404: This AST is governed by the ontological rules dictated in
                    405: .Xr man 7
                    406: and derives its terminology accordingly.
                    407: .Pp
                    408: The AST is composed of
                    409: .Vt struct man_node
                    410: nodes with element, root and text types as declared by the
                    411: .Va type
                    412: field.
                    413: Each node also provides its parse point (the
                    414: .Va line ,
                    415: .Va sec ,
                    416: and
                    417: .Va pos
                    418: fields), its position in the tree (the
                    419: .Va parent ,
                    420: .Va child ,
                    421: .Va next
                    422: and
                    423: .Va prev
                    424: fields) and some type-specific data.
                    425: .Pp
                    426: The tree itself is arranged according to the following normal form,
                    427: where capitalised non-terminals represent nodes.
                    428: .Pp
                    429: .Bl -tag -width "ELEMENTXX" -compact
                    430: .It ROOT
                    431: \(<- mnode+
                    432: .It mnode
                    433: \(<- ELEMENT | TEXT | BLOCK
                    434: .It BLOCK
                    435: \(<- HEAD BODY
                    436: .It HEAD
                    437: \(<- mnode*
                    438: .It BODY
                    439: \(<- mnode*
                    440: .It ELEMENT
                    441: \(<- ELEMENT | TEXT*
                    442: .It TEXT
1.11      kristaps  443: \(<- [[:ascii:]]*
1.1       kristaps  444: .El
                    445: .Pp
                    446: The only elements capable of nesting other elements are those with
                    447: next-lint scope as documented in
                    448: .Xr man 7 .
                    449: .Ss Mdoc Abstract Syntax Tree
                    450: This AST is governed by the ontological
                    451: rules dictated in
                    452: .Xr mdoc 7
                    453: and derives its terminology accordingly.
                    454: .Qq In-line
                    455: elements described in
                    456: .Xr mdoc 7
                    457: are described simply as
                    458: .Qq elements .
                    459: .Pp
                    460: The AST is composed of
                    461: .Vt struct mdoc_node
                    462: nodes with block, head, body, element, root and text types as declared
                    463: by the
                    464: .Va type
                    465: field.
                    466: Each node also provides its parse point (the
                    467: .Va line ,
                    468: .Va sec ,
                    469: and
                    470: .Va pos
                    471: fields), its position in the tree (the
                    472: .Va parent ,
                    473: .Va child ,
                    474: .Va nchild ,
                    475: .Va next
                    476: and
                    477: .Va prev
                    478: fields) and some type-specific data, in particular, for nodes generated
                    479: from macros, the generating macro in the
                    480: .Va tok
                    481: field.
                    482: .Pp
                    483: The tree itself is arranged according to the following normal form,
                    484: where capitalised non-terminals represent nodes.
                    485: .Pp
                    486: .Bl -tag -width "ELEMENTXX" -compact
                    487: .It ROOT
                    488: \(<- mnode+
                    489: .It mnode
                    490: \(<- BLOCK | ELEMENT | TEXT
                    491: .It BLOCK
                    492: \(<- HEAD [TEXT] (BODY [TEXT])+ [TAIL [TEXT]]
                    493: .It ELEMENT
                    494: \(<- TEXT*
                    495: .It HEAD
                    496: \(<- mnode*
                    497: .It BODY
                    498: \(<- mnode* [ENDBODY mnode*]
                    499: .It TAIL
                    500: \(<- mnode*
                    501: .It TEXT
1.11      kristaps  502: \(<- [[:ascii:]]*
1.1       kristaps  503: .El
                    504: .Pp
                    505: Of note are the TEXT nodes following the HEAD, BODY and TAIL nodes of
                    506: the BLOCK production: these refer to punctuation marks.
                    507: Furthermore, although a TEXT node will generally have a non-zero-length
                    508: string, in the specific case of
                    509: .Sq \&.Bd \-literal ,
                    510: an empty line will produce a zero-length string.
                    511: Multiple body parts are only found in invocations of
                    512: .Sq \&Bl \-column ,
                    513: where a new body introduces a new phrase.
                    514: .Pp
                    515: The
                    516: .Xr mdoc 7
1.5       kristaps  517: syntax tree accommodates for broken block structures as well.
1.1       kristaps  518: The ENDBODY node is available to end the formatting associated
                    519: with a given block before the physical end of that block.
                    520: It has a non-null
                    521: .Va end
                    522: field, is of the BODY
                    523: .Va type ,
                    524: has the same
                    525: .Va tok
                    526: as the BLOCK it is ending, and has a
                    527: .Va pending
                    528: field pointing to that BLOCK's BODY node.
                    529: It is an indirect child of that BODY node
                    530: and has no children of its own.
                    531: .Pp
                    532: An ENDBODY node is generated when a block ends while one of its child
                    533: blocks is still open, like in the following example:
                    534: .Bd -literal -offset indent
                    535: \&.Ao ao
                    536: \&.Bo bo ac
                    537: \&.Ac bc
                    538: \&.Bc end
                    539: .Ed
                    540: .Pp
                    541: This example results in the following block structure:
                    542: .Bd -literal -offset indent
                    543: BLOCK Ao
                    544:     HEAD Ao
                    545:     BODY Ao
                    546:         TEXT ao
                    547:         BLOCK Bo, pending -> Ao
                    548:             HEAD Bo
                    549:             BODY Bo
                    550:                 TEXT bo
                    551:                 TEXT ac
                    552:                 ENDBODY Ao, pending -> Ao
                    553:                 TEXT bc
                    554: TEXT end
                    555: .Ed
                    556: .Pp
                    557: Here, the formatting of the
                    558: .Sq \&Ao
                    559: block extends from TEXT ao to TEXT ac,
                    560: while the formatting of the
                    561: .Sq \&Bo
                    562: block extends from TEXT bo to TEXT bc.
                    563: It renders as follows in
                    564: .Fl T Ns Cm ascii
                    565: mode:
                    566: .Pp
                    567: .Dl <ao [bo ac> bc] end
                    568: .Pp
                    569: Support for badly-nested blocks is only provided for backward
                    570: compatibility with some older
                    571: .Xr mdoc 7
                    572: implementations.
                    573: Using badly-nested blocks is
                    574: .Em strongly discouraged ;
                    575: for example, the
                    576: .Fl T Ns Cm html
                    577: and
                    578: .Fl T Ns Cm xhtml
                    579: front-ends to
                    580: .Xr mandoc 1
                    581: are unable to render them in any meaningful way.
                    582: Furthermore, behaviour when encountering badly-nested blocks is not
                    583: consistent across troff implementations, especially when using  multiple
                    584: levels of badly-nested blocks.
                    585: .Sh SEE ALSO
                    586: .Xr mandoc 1 ,
                    587: .Xr eqn 7 ,
                    588: .Xr man 7 ,
1.6       kristaps  589: .Xr mandoc_char 7 ,
1.1       kristaps  590: .Xr mdoc 7 ,
                    591: .Xr roff 7 ,
                    592: .Xr tbl 7
                    593: .Sh AUTHORS
                    594: The
                    595: .Nm
                    596: library was written by
1.13      kristaps  597: .An Kristaps Dzonsons ,
                    598: .Mt kristaps@bsd.lv .

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