Parses text into syntax trees based using a parser selected from a set of built-in parsers.
The REx parser generator was used to generate the parsers.
This release uses the -basex option of REx to generate Java for BaseX.
It can be used to implement the EXPath xparse proposal .
This release requires BaseX 8.6+. This is a result of XQuery spec changes to map:merge
import module namespace xp="expkg-zone58:text.parse";
xp:parse("2+3",map{"lang":"xquery","version":"3.1 basex"}) The second argument provides options to control the parsing of the text from the first argument.
| Option | Type--- | Values | Default | Notes |
|---|---|---|---|---|
| lang | xs:string | XPath, XQuery | XPath | The language to be parsed |
| version | xs:string | "" | ||
| flatten | xs:boolean | true() | Flatten the parse tree |
The selected parser is chosen from the list in parser.xml. where the lang matches and version starts-with. see xp:parser($opts)
flatten skips elements with only one child element and no text.
<parsers xmlns="expkg-zone58:text.parse">
<!-- available languages and versions with REx parser implementation options.
add "-tree -java -basex" -->
<parser lang="xpath">
<version version="3.0" ebnf="xpath-30" sym="XPath" />
<version version="3.1" ebnf="xpath-31" sym="XPath" />
</parser>
<parser lang="xquery">
<version version="3.1 basex-2022-10-06" ebnf="BaseX" sym="XQuery"
options="-ll 2 -backtrack " >For BaseX 9 includes XQuery update and full-text. Does not include http://docs.basex.org/wiki/XQuery_Extensions#Expressions</version>
<version version="3.1" ebnf="xquery-31" sym="XQuery" />
<version version="3.0" ebnf="xquery-30" sym="XQuery" />
<version version="1.0" ebnf="xquery-10" sym="XQuery" />
<version version="3.0 ML" ebnf="XQueryML30" sym="XQuery"
options="-backtrack" />
</parser>
<parser lang="xqdoc-comments">
<version version="20160405" ebnf="XQDocComments" sym="Comments" />
</parser>
<parser lang="ecmascript">
<version version="5" ebnf="EcmaScript" sym="Program"
options="-ll 1 -backtrack -asi" />
</parser>
<parser lang="rex">
<version version="5.49" ebnf="REx" sym="Grammar" />
</parser>
</parsers>import module namespace xp="expkg-zone58:text.parse";
xp:parse("2+3",map{"lang":"xquery"}) result
<XQuery>
<MainModule>
<Prolog/>
<AdditiveExpr>
<IntegerLiteral>2</IntegerLiteral>
<TOKEN>+</TOKEN>
<IntegerLiteral>3</IntegerLiteral>
</AdditiveExpr>
</MainModule>
<EOF/>
</XQuery>
With options
import module namespace xp="expkg-zone58:text.parse";
xp:parse("1+2",map{"lang":"xpath","flatten":false()})Result:
<XPath>
<Expr>
<ExprSingle>
<OrExpr>
<AndExpr>
<ComparisonExpr>
<StringConcatExpr>
<RangeExpr>
<AdditiveExpr>
<MultiplicativeExpr>
<UnionExpr>
<IntersectExceptExpr>
<InstanceofExpr>
<TreatExpr>
<CastableExpr>
<CastExpr>
<UnaryExpr>
<ValueExpr>
<SimpleMapExpr>
<PathExpr>
<RelativePathExpr>
<StepExpr>
<PostfixExpr>
<PrimaryExpr>
<Literal>
<NumericLiteral>
<IntegerLiteral>1</IntegerLiteral>
</NumericLiteral>
</Literal>
</PrimaryExpr>
</PostfixExpr>
</StepExpr>
</RelativePathExpr>
</PathExpr>
</SimpleMapExpr>
</ValueExpr>
</UnaryExpr>
</CastExpr>
</CastableExpr>
</TreatExpr>
</InstanceofExpr>
</IntersectExceptExpr>
</UnionExpr>
</MultiplicativeExpr>
<TOKEN>+</TOKEN>
<MultiplicativeExpr>
<UnionExpr>
<IntersectExceptExpr>
<InstanceofExpr>
<TreatExpr>
<CastableExpr>
<CastExpr>
<UnaryExpr>
<ValueExpr>
<SimpleMapExpr>
<PathExpr>
<RelativePathExpr>
<StepExpr>
<PostfixExpr>
<PrimaryExpr>
<Literal>
<NumericLiteral>
<IntegerLiteral>2</IntegerLiteral>
</NumericLiteral>
</Literal>
</PrimaryExpr>
</PostfixExpr>
</StepExpr>
</RelativePathExpr>
</PathExpr>
</SimpleMapExpr>
</ValueExpr>
</UnaryExpr>
</CastExpr>
</CastableExpr>
</TreatExpr>
</InstanceofExpr>
</IntersectExceptExpr>
</UnionExpr>
</MultiplicativeExpr>
</AdditiveExpr>
</RangeExpr>
</StringConcatExpr>
</ComparisonExpr>
</AndExpr>
</OrExpr>
</ExprSingle>
</Expr>
<EOF/>
</XPath>
Versions
import module namespace xp="expkg-zone58:text.parse";
xp:parse("map{'a':42}",map{"lang":"xquery"})
Result
<XQuery>
<MainModule>
<Prolog/>
<MapConstructor>
<TOKEN>map</TOKEN>
<TOKEN>{</TOKEN>
<MapConstructorEntry>
<StringLiteral>'a'</StringLiteral>
<TOKEN>:</TOKEN>
<IntegerLiteral>42</IntegerLiteral>
</MapConstructorEntry>
<TOKEN>}</TOKEN>
</MapConstructor>
</MainModule>
<EOF/>
</XQuery>
import module namespace xp="expkg-zone58:text.parse";
xp:parse("map{'a':42}",map{"lang":"xquery","version":"3.0"})
Result
<ERROR b="4" e="4" s="158">lexical analysis failed
while expecting [S, EOF, '!', '!=', '#', '(', '(:', ')', '*', '+', ',', '-', '/', '//', ';', '<', '<<', '<=', '=', '>', '>=', '>>', '[', ']', 'and', 'ascending', 'case', 'cast', 'castable', 'collation', 'count', 'default', 'descending', 'div', 'else', 'empty', 'end', 'eq', 'except', 'for', 'ge', 'group', 'gt', 'idiv', 'instance', 'intersect', 'is', 'le', 'let', 'lt', 'mod', 'ne', 'only', 'or', 'order', 'return', 'satisfies', 'stable', 'start', 'to', 'treat', 'union', 'where', '|', '||', '}']
at line 1, column 4:
...{'a':42}...</ERROR>
- create ebnf in
content/ebnf - add entry in
parsers.xml
- run
tools/rex.xqto create java files insrc/javafor all ebnfs referenced inparsers.xml - run
tools/makejar.xqto create jars insrc/java - copy jars to
main/content - increment version in
main/expath-pkg.xml - run
tools/build.xq
- versions before 0.5 used the namespace
http://expath.org/ns/xparse