Chapter 9: Regular expressions

Book examples

Example 9-1. A simple type with a pattern

<xs:simpleType name="ProductNumberType">
  <xs:restriction base="xs:string">
    <xs:pattern value="\d{3}-[A-Z]{2}|\d{7}"/>
  </xs:restriction>
</xs:simpleType>

Table 9-1. Using normal characters

Regular expression	Matching strings	Non-matching strings
`a`	`a`	`b`
`a\|b\|c`	`a, b, c`	`abc`

Table 9-3. Using character references

Regular expression	Matching strings	Non-matching strings
`a z`	`a z`	`az`
`a *z`	`az, a z, a z, a z`	`a *z`
`PB&J`	`PB&J`	`PBJ`

Table 9-4. Using the wildcard escape character

Regular expression	Matching strings	Non-matching strings
`a.z`	`aaz, abz, a2z`	`az, abbz`
`a..z`	`aaaz, abcz, a12z`	`az, abz`
`a.*z`	`az, abz, abcdez`	`a b`
`a\.z`	`a.z`	`abz`
`.abc.`	`abc, xxxabc, abcxxx, xxxabcxxx`	`xxx`
`.*abc`	`abc, xxxabc`	`abcxxx, xxxabcxxx`
`abc.*`	`abc, abcxxx`	`xxxabc, xxxabcxxx`

Table 9-6. Using single-character escapes

Regular expression	Matching strings	Non-matching strings
`1+2`	`12, 112, 1112`	`1+2`
`1\+2`	`1+2`	`12, 1\+2`
`1\++2`	`1+2, 1++2, 1+++2`	`12`

Table 9-8. Using multi-character escapes

Regular expression	Matching strings	Non-matching strings
`a\dz`	`a0z, a1z`	`az, adz, a12z`
`a\s*z`	`az, a Š z`	`axz`

Table 9-10. Using category escapes

Regular expression	Matching strings	Non-matching strings
`\p{Lu}`	`A, B, C`	`a, b, c, 1, 2, 3`
`\P{Lu}`	`a, b, c, 1, 2, 3`	`A, B, C`
`\p{Nd}`	`1, 2, 3`	`a, b, c, A, B, C`
`\P{Nd}`	`a, b, c, A, B, C`	`1, 2, 3`

Table 9-12. Using block escapes

Regular expression	Matching strings	Non-matching strings
`\p{IsBasicLatin}`	`a, b, c`	`â, ß, ç`
`\P{IsBasicLatin}`	`â, ß, ç`	`a, b, c`

Table 9-13. Specifying a list of characters

Regular expression	Matching strings	Non-matching strings
`[abc]z`	`az, bz, cz`	`abz, z, abcz, abc`
`[\p{Lu}\d]z`	`Az, Bz, 1z, 2z`	`az, bz, cz, A1z`

Table 9-14. Specifying a range

Regular expression	Matching strings	Non-matching strings
`[a-f]z`	`az, fz`	`z, abz, gz, hz`
`[0-9a-fA-F]z`	`1z, az, Bz`	`z, gz, Gz, 1aBz`
`[ -]z`	`az, bz, cz`	`âz`

Table 9-15. Combining characters and ranges

Regular expression	Matching strings	Non-matching strings
`[0-9pqr]z`	`1z, 2z, pz, rz`	`cz,dz, 0sz`
`[p-r\d]z`	`1z, 2z, pz, rz`	`cz,dz, 0sz`

Table 9-16. Negating a character class expression

Regular expression	Matching strings	Non-matching strings
`[^ab]z`	`cz, dz, 1z`	`az, bz`
`[^\d]z`	`az, bz, cz`	`1z, 2z, 3z`
`[^1-3a-c]z`	`dz, 4z`	`1z, az`

Table 9-17. Subtracting from a character class expression

Regular expression	Matching strings	Non-matching strings
`[a-z-[c]]z`	`az, dz, ez, zz`	`cz`
`[a-z-[cd]]z`	`az, ez, zz`	`cz, dz`
`[a-z-[c-e]]z`	`az, zz`	`cz, dz, ez, 1z`
`[^a-z-[123]]z`	`4z`	`az, 3z, zz`

Table 9-18. Using parenthesized regular expressions

Regular expression	Matching strings	Non-matching strings
`(ab)*z`	`z, abz, ababz`	`az, bz, aabbz`
`(ab\|cd)z`	`abz, cdz`	`abcdz, z`
`(a+b)*z`	`z, abz, aabz, abaabz`	`az, abbz`
`([a-f]x)*z`	`z, axz, bxfxfxz`	`gxz, xz`
`(\db)*z`	`z, 1bz, 1b2bz`	`1z, bz`

Table 9-20. Using quantifiers

Regular expression	Matching strings	Non-matching strings
`abz`	`abz`	`az, abbz`
`ab?z`	`az, abz`	`abbz`
`ab*z`	`az, abz, abbz, abbbz, ...`	`a1z`
`ab+z`	`abz, abbz, abbbz, ...`	`az`
`ab{2}z`	`abbz`	`abz, abbbz`
`ab{2,}z`	`abbz, abbbz, abbbbz, ...`	`az, abz`
`ab{2,3}z`	`abbz, abbbz`	`az, abz, abbbbz`
`a[b-d]+z`	`abz, abdz, addbccdddz`	`az, aez, abez`
`a\p{Nd}+z`	`a1z, a11z, a234z`	`az, abcz`
`a(bc)+z`	`abcz, abcbcz, abcbcbcz, ...`	`az, abz, acbz`

Table 9-21. Branches, expressions and parentheses

Regular expression	Matching strings	Non-matching strings
`true\|false`	`true, false`	`trufalse`
`tru(e\|f)alse`	`trufalse`	`true, false`
`yes\|no\|maybe`	`yes, no, maybe`	`yenoaybe`
`(a\|b)c\|d`	`ac, bc, d`	`c, ad`