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Diffstat (limited to 'nimlib/pure/parsexml.nim')
| -rwxr-xr-x | nimlib/pure/parsexml.nim | 635 |
1 files changed, 0 insertions, 635 deletions
diff --git a/nimlib/pure/parsexml.nim b/nimlib/pure/parsexml.nim deleted file mode 100755 index 54f62a9a4..000000000 --- a/nimlib/pure/parsexml.nim +++ /dev/null @@ -1,635 +0,0 @@ -# -# -# Nimrod's Runtime Library -# (c) Copyright 2009 Andreas Rumpf -# -# See the file "copying.txt", included in this -# distribution, for details about the copyright. -# - -## This module implements a simple high performance `XML`:idx: / `HTML`:idx: -## parser. -## The only encoding that is supported is UTF-8. The parser has been designed -## to be somewhat error correcting, so that even most "wild HTML" found on the -## web can be parsed with it. **Note:** This parser does not check that each -## ``<tag>`` has a corresponding ``</tag>``! These checks have do be -## implemented by the client code for various reasons: -## -## * Old HTML contains tags that have no end tag: ``<br>`` for example. -## * HTML tags are case insensitive, XML tags are case sensitive. Since this -## library can parse both, only the client knows which comparison is to be -## used. -## * Thus the checks would have been very difficult to implement properly with -## little benefit, especially since they are simple to implement in the -## client. The client should use the `errorMsgExpected` proc to generate -## a nice error message that fits the other error messages this library -## creates. -## -## -## Example 1: Retrieve HTML title -## ============================== -## -## The file ``examples/htmltitle.nim`` demonstrates how to use the -## XML parser to accomplish a simple task: To determine the title of an HTML -## document. -## -## .. code-block:: nimrod -## :file: examples/htmltitle.nim -## -## -## Example 2: Retrieve all HTML links -## ================================== -## -## The file ``examples/htmlrefs.nim`` demonstrates how to use the -## XML parser to accomplish another simple task: To determine all the links -## an HTML document contains. -## -## .. code-block:: nimrod -## :file: examples/htmlrefs.nim -## - -import - hashes, strutils, lexbase, streams, unicode - -# the parser treats ``<br />`` as ``<br></br>`` - -type - TXmlEventKind* = enum ## enumation of all events that may occur when parsing - xmlError, ## an error ocurred during parsing - xmlEof, ## end of file reached - xmlCharData, ## character data - xmlWhitespace, ## whitespace has been parsed - xmlComment, ## a comment has been parsed - xmlPI, ## processing instruction (``<?name something ?>``) - xmlElementStart, ## ``<elem>`` - xmlElementEnd, ## ``</elem>`` - xmlElementOpen, ## ``<elem - xmlAttribute, ## ``key = "value"`` pair - xmlElementClose, ## ``>`` - xmlCData, ## ``<![CDATA[`` ... data ... ``]]>`` - xmlEntity, ## &entity; - xmlSpecial ## ``<! ... data ... >`` - - TXmlError* = enum ## enumeration that lists all errors that can occur - errNone, ## no error - errEndOfCDataExpected, ## ``]]>`` expected - errNameExpected, ## name expected - errSemicolonExpected, ## ``;`` expected - errQmGtExpected, ## ``?>`` expected - errGtExpected, ## ``>`` expected - errEqExpected, ## ``=`` expected - errQuoteExpected, ## ``"`` or ``'`` expected - errEndOfCommentExpected ## ``-->`` expected - - TParserState = enum - stateStart, stateNormal, stateAttr, stateEmptyElementTag, stateError - - TXmlParseOption* = enum ## options for the XML parser - reportWhitespace, ## report whitespace - reportComments ## report comments - - TXmlParser* = object of TBaseLexer ## the parser object. - a, b: string - kind: TXmlEventKind - err: TXmlError - state: TParserState - filename: string - options: set[TXmlParseOption] - -const - errorMessages: array [TXmlError, string] = [ - "no error", - "']]>' expected", - "name expected", - "';' expected", - "'?>' expected", - "'>' expected", - "'=' expected", - "'\"' or \"'\" expected", - "'-->' expected" - ] - -proc open*(my: var TXmlParser, input: PStream, filename: string, - options: set[TXmlParseOption] = {}) = - ## initializes the parser with an input stream. `Filename` is only used - ## for nice error messages. The parser's behaviour can be controlled by - ## the `options` parameter: If `options` contains ``reportWhitespace`` - ## a whitespace token is reported as an ``xmlWhitespace`` event. - ## If `options` contains ``reportComments`` a comment token is reported as an - ## ``xmlComment`` event. - lexbase.open(my, input) - my.filename = filename - my.state = stateStart - my.kind = xmlError - my.a = "" - my.b = "" - my.options = options - -proc close*(my: var TXmlParser) {.inline.} = - ## closes the parser `my` and its associated input stream. - lexbase.close(my) - -proc charData*(my: TXmlParser): string {.inline.} = - ## returns the character data for the events: ``xmlCharData``, - ## ``xmlWhitespace``, ``xmlComment``, ``xmlCData``, ``xmlSpecial`` - assert(my.kind in {xmlCharData, xmlWhitespace, xmlComment, xmlCData, - xmlSpecial}) - return my.a - -proc kind*(my: TXmlParser): TXmlEventKind {.inline.} = - ## returns the current event type for the XML parser - return my.kind - -proc elementName*(my: TXmlParser): string {.inline.} = - ## returns the element name for the events: ``xmlElementStart``, - ## ``xmlElementEnd``, ``xmlElementOpen`` - assert(my.kind in {xmlElementStart, xmlElementEnd, xmlElementOpen}) - return my.a - -proc entityName*(my: TXmlParser): string {.inline.} = - ## returns the entity name for the event: ``xmlEntity`` - assert(my.kind == xmlEntity) - return my.a - -proc attrKey*(my: TXmlParser): string {.inline.} = - ## returns the attribute key for the event ``xmlAttribute`` - assert(my.kind == xmlAttribute) - return my.a - -proc attrValue*(my: TXmlParser): string {.inline.} = - ## returns the attribute value for the event ``xmlAttribute`` - assert(my.kind == xmlAttribute) - return my.b - -proc PIName*(my: TXmlParser): string {.inline.} = - ## returns the processing instruction name for the event ``xmlPI`` - assert(my.kind == xmlPI) - return my.a - -proc PIRest*(my: TXmlParser): string {.inline.} = - ## returns the rest of the processing instruction for the event ``xmlPI`` - assert(my.kind == xmlPI) - return my.b - -proc getColumn*(my: TXmlParser): int {.inline.} = - ## get the current column the parser has arrived at. - result = getColNumber(my, my.bufPos) - -proc getLine*(my: TXmlParser): int {.inline.} = - ## get the current line the parser has arrived at. - result = my.linenumber - -proc getFilename*(my: TXmlParser): string {.inline.} = - ## get the filename of the file that the parser processes. - result = my.filename - -proc errorMsg*(my: TXmlParser): string = - ## returns a helpful error message for the event ``xmlError`` - assert(my.kind == xmlError) - result = "$1($2, $3) Error: $4" % [ - my.filename, $getLine(my), $getColumn(my), errorMessages[my.err]] - -proc errorMsgExpected*(my: TXmlParser, tag: string): string = - ## returns an error message "<tag> expected" in the same format as the - ## other error messages - result = "$1($2, $3) Error: $4" % [ - my.filename, $getLine(my), $getColumn(my), "<$1> expected" % tag] - -proc markError(my: var TXmlParser, kind: TXmlError) {.inline.} = - my.err = kind - my.state = stateError - -proc parseCDATA(my: var TXMLParser) = - var pos = my.bufpos + len("<![CDATA[") - var buf = my.buf - while true: - case buf[pos] - of ']': - if buf[pos+1] == ']' and buf[pos+2] == '>': - inc(pos, 3) - break - add(my.a, ']') - inc(pos) - of '\0': - markError(my, errEndOfCDataExpected) - break - of '\c': - pos = lexbase.HandleCR(my, pos) - buf = my.buf - add(my.a, '\L') - of '\L': - pos = lexbase.HandleLF(my, pos) - buf = my.buf - add(my.a, '\L') - else: - add(my.a, buf[pos]) - inc(pos) - my.bufpos = pos # store back - my.kind = xmlCDATA - -proc parseComment(my: var TXMLParser) = - var pos = my.bufpos + len("<!--") - var buf = my.buf - while true: - case buf[pos] - of '-': - if buf[pos+1] == '-' and buf[pos+2] == '>': - inc(pos, 3) - break - if my.options.contains(reportComments): add(my.a, '-') - inc(pos) - of '\0': - markError(my, errEndOfCommentExpected) - break - of '\c': - pos = lexbase.HandleCR(my, pos) - buf = my.buf - if my.options.contains(reportComments): add(my.a, '\L') - of '\L': - pos = lexbase.HandleLF(my, pos) - buf = my.buf - if my.options.contains(reportComments): add(my.a, '\L') - else: - if my.options.contains(reportComments): add(my.a, buf[pos]) - inc(pos) - my.bufpos = pos - my.kind = xmlComment - -proc parseWhitespace(my: var TXmlParser, skip=False) = - var pos = my.bufpos - var buf = my.buf - while true: - case buf[pos] - of ' ', '\t': - if not skip: add(my.a, buf[pos]) - Inc(pos) - of '\c': - # the specification says that CR-LF, CR are to be transformed to LF - pos = lexbase.HandleCR(my, pos) - buf = my.buf - if not skip: add(my.a, '\L') - of '\L': - pos = lexbase.HandleLF(my, pos) - buf = my.buf - if not skip: add(my.a, '\L') - else: - break - my.bufpos = pos - -const - NameStartChar = {'A'..'Z', 'a'..'z', '_', ':', '\128'..'\255'} - NameChar = {'A'..'Z', 'a'..'z', '0'..'9', '.', '-', '_', ':', '\128'..'\255'} - -proc parseName(my: var TXmlParser, dest: var string) = - var pos = my.bufpos - var buf = my.buf - if buf[pos] in nameStartChar: - while true: - add(dest, buf[pos]) - inc(pos) - if buf[pos] notin NameChar: break - my.bufpos = pos - else: - markError(my, errNameExpected) - -proc parseEntity(my: var TXmlParser, dest: var string) = - var pos = my.bufpos+1 - var buf = my.buf - my.kind = xmlCharData - if buf[pos] == '#': - var r: int - inc(pos) - if buf[pos] == 'x': - inc(pos) - while true: - case buf[pos] - of '0'..'9': r = (r shl 4) or (ord(buf[pos]) - ord('0')) - of 'a'..'f': r = (r shl 4) or (ord(buf[pos]) - ord('a') + 10) - of 'A'..'F': r = (r shl 4) or (ord(buf[pos]) - ord('A') + 10) - else: break - inc(pos) - else: - while buf[pos] in {'0'..'9'}: - r = r * 10 + (ord(buf[pos]) - ord('0')) - inc(pos) - add(dest, toUTF8(TRune(r))) - elif buf[pos] == 'l' and buf[pos+1] == 't': - add(dest, '<') - inc(pos, 2) - elif buf[pos] == 'g' and buf[pos+1] == 't': - add(dest, '>') - inc(pos, 2) - elif buf[pos] == 'a' and buf[pos+1] == 'm' and buf[pos+2] == 'p': - add(dest, '&') - inc(pos, 3) - elif buf[pos] == 'a' and buf[pos+1] == 'p' and buf[pos+2] == 'o' and - buf[pos+3] == 's': - add(dest, '\'') - inc(pos, 4) - elif buf[pos] == 'q' and buf[pos+1] == 'u' and buf[pos+2] == 'o' and - buf[pos+3] == 't': - add(dest, '"') - inc(pos, 4) - else: - my.bufpos = pos - parseName(my, dest) - pos = my.bufpos - if my.err != errNameExpected: - my.kind = xmlEntity - else: - add(dest, '&') - if buf[pos] == ';': - inc(pos) - else: - markError(my, errSemiColonExpected) - my.bufpos = pos - -proc parsePI(my: var TXmlParser) = - inc(my.bufpos, "<?".len) - parseName(my, my.a) - var pos = my.bufpos - var buf = my.buf - setLen(my.b, 0) - while true: - case buf[pos] - of '\0': - markError(my, errQmGtExpected) - break - of '?': - if buf[pos+1] == '>': - inc(pos, 2) - break - add(my.b, '?') - inc(pos) - of '\c': - # the specification says that CR-LF, CR are to be transformed to LF - pos = lexbase.HandleCR(my, pos) - buf = my.buf - add(my.b, '\L') - of '\L': - pos = lexbase.HandleLF(my, pos) - buf = my.buf - add(my.b, '\L') - else: - add(my.b, buf[pos]) - inc(pos) - my.bufpos = pos - my.kind = xmlPI - -proc parseSpecial(my: var TXmlParser) = - # things that start with <! - var pos = my.bufpos + 2 - var buf = my.buf - var opentags = 0 - while true: - case buf[pos] - of '\0': - markError(my, errGtExpected) - break - of '<': - inc(opentags) - inc(pos) - add(my.a, '<') - of '>': - if opentags <= 0: - inc(pos) - break - dec(opentags) - inc(pos) - add(my.a, '>') - of '\c': - pos = lexbase.HandleCR(my, pos) - buf = my.buf - add(my.a, '\L') - of '\L': - pos = lexbase.HandleLF(my, pos) - buf = my.buf - add(my.a, '\L') - else: - add(my.a, buf[pos]) - inc(pos) - my.bufpos = pos - my.kind = xmlSpecial - -proc parseTag(my: var TXmlParser) = - inc(my.bufpos) - parseName(my, my.a) - # if we have no name, do not interpret the '<': - if my.a.len == 0: - my.kind = xmlCharData - add(my.a, '<') - return - parseWhitespace(my, skip=True) - if my.buf[my.bufpos] in NameStartChar: - # an attribute follows: - my.kind = xmlElementOpen - my.state = stateAttr - else: - my.kind = xmlElementStart - if my.buf[my.bufpos] == '/' and my.buf[my.bufpos+1] == '>': - inc(my.bufpos, 2) - my.state = stateEmptyElementTag - elif my.buf[my.bufpos] == '>': - inc(my.bufpos) - else: - markError(my, errGtExpected) - -proc parseEndTag(my: var TXmlParser) = - inc(my.bufpos, 2) - parseName(my, my.a) - parseWhitespace(my, skip=True) - if my.buf[my.bufpos] == '>': - inc(my.bufpos) - else: - markError(my, errGtExpected) - my.kind = xmlElementEnd - -proc parseAttribute(my: var TXmlParser) = - my.kind = xmlAttribute - setLen(my.a, 0) - setLen(my.b, 0) - parseName(my, my.a) - # if we have no name, we have '<tag attr= key %&$$%': - if my.a.len == 0: - markError(my, errGtExpected) - return - parseWhitespace(my, skip=True) - if my.buf[my.bufpos] != '=': - markError(my, errEqExpected) - return - inc(my.bufpos) - parseWhitespace(my, skip=True) - - var pos = my.bufpos - var buf = my.buf - if buf[pos] in {'\'', '"'}: - var quote = buf[pos] - var pendingSpace = false - inc(pos) - while true: - case buf[pos] - of '\0': - markError(my, errQuoteExpected) - break - of '&': - if pendingSpace: - add(my.b, ' ') - pendingSpace = false - my.bufpos = pos - parseEntity(my, my.b) - my.kind = xmlAttribute # parseEntity overwrites my.kind! - pos = my.bufpos - of ' ', '\t': - pendingSpace = true - inc(pos) - of '\c': - pos = lexbase.HandleCR(my, pos) - buf = my.buf - pendingSpace = true - of '\L': - pos = lexbase.HandleLF(my, pos) - buf = my.buf - pendingSpace = true - else: - if buf[pos] == quote: - inc(pos) - break - else: - if pendingSpace: - add(my.b, ' ') - pendingSpace = false - add(my.b, buf[pos]) - inc(pos) - else: - markError(my, errQuoteExpected) - my.bufpos = pos - parseWhitespace(my, skip=True) - -proc parseCharData(my: var TXmlParser) = - var pos = my.bufpos - var buf = my.buf - while true: - case buf[pos] - of '\0', '<', '&': break - of '\c': - # the specification says that CR-LF, CR are to be transformed to LF - pos = lexbase.HandleCR(my, pos) - buf = my.buf - add(my.a, '\L') - of '\L': - pos = lexbase.HandleLF(my, pos) - buf = my.buf - add(my.a, '\L') - else: - add(my.a, buf[pos]) - inc(pos) - my.bufpos = pos - my.kind = xmlCharData - -proc rawGetTok(my: var TXmlParser) = - my.kind = xmlError - setLen(my.a, 0) - var pos = my.bufpos - var buf = my.buf - case buf[pos] - of '<': - case buf[pos+1] - of '/': - parseEndTag(my) - of '!': - if buf[pos+2] == '[' and buf[pos+3] == 'C' and buf[pos+4] == 'D' and - buf[pos+5] == 'A' and buf[pos+6] == 'T' and buf[pos+7] == 'A' and - buf[pos+8] == '[': - parseCDATA(my) - elif buf[pos+2] == '-' and buf[pos+3] == '-': - parseComment(my) - else: - parseSpecial(my) - of '?': - parsePI(my) - else: - parseTag(my) - of ' ', '\t', '\c', '\l': - parseWhiteSpace(my) - my.kind = xmlWhitespace - of '\0': - my.kind = xmlEof - of '&': - parseEntity(my, my.a) - else: - parseCharData(my) - assert my.kind != xmlError - -proc getTok(my: var TXmlParser) = - while true: - rawGetTok(my) - case my.kind - of xmlComment: - if my.options.contains(reportComments): break - of xmlWhitespace: - if my.options.contains(reportWhitespace): break - else: break - -proc next*(my: var TXmlParser) = - ## retrieves the first/next event. This controls the parser. - case my.state - of stateNormal: - getTok(my) - of stateStart: - getTok(my) - if my.kind == xmlPI and my.a == "xml": - # just skip the first ``<?xml >`` processing instruction - getTok(my) - my.state = stateNormal - of stateAttr: - # parse an attribute key-value pair: - if my.buf[my.bufpos] == '>': - my.kind = xmlElementClose - inc(my.bufpos) - my.state = stateNormal - elif my.buf[my.bufpos] == '/' and my.buf[my.bufpos+1] == '>': - my.kind = xmlElementClose - inc(my.bufpos, 2) - my.state = stateEmptyElementTag - else: - parseAttribute(my) - # state remains the same - of stateEmptyElementTag: - my.state = stateNormal - my.kind = xmlElementEnd - of stateError: - my.kind = xmlError - my.state = stateNormal - -when isMainModule: - import os - var s = newFileStream(ParamStr(1), fmRead) - if s == nil: quit("cannot open the file" & ParamStr(1)) - var x: TXmlParser - open(x, s, ParamStr(1)) - while true: - next(x) - case x.kind - of xmlError: Echo(x.errorMsg()) - of xmlEof: break - of xmlCharData: echo(x.charData) - of xmlWhitespace: echo("|$1|" % x.charData) - of xmlComment: echo("<!-- $1 -->" % x.charData) - of xmlPI: echo("<? $1 ## $2 ?>" % [x.PIName, x.PIRest]) - of xmlElementStart: echo("<$1>" % x.elementName) - of xmlElementEnd: echo("</$1>" % x.elementName) - - of xmlElementOpen: echo("<$1" % x.elementName) - of xmlAttribute: - echo("Key: " & x.attrKey) - echo("Value: " & x.attrValue) - - of xmlElementClose: echo(">") - of xmlCData: - echo("<![CDATA[$1]]>" % x.charData) - of xmlEntity: - echo("&$1;" % x.entityName) - of xmlSpecial: - echo("SPECIAL: " & x.charData) - close(x) - |