Julia中字符串中正则表达式的匹配——match()和eachmatch()方法

match()是 julia 中的一个内置函数，用于在指定字符串s中搜索给定正则表达式r的第一个匹配项，然后返回包含匹配项的 RegexMatch 对象，如果匹配失败则返回任何内容。

Syntax:
match(r::Regex, s::AbstractString, idx::Integer)

Parameters:

• r::Regex: Specified regular expression.
• s::AbstractString: Specified string.
• idx::Integer: It specifies the point from which the searching get started.

Returns: It returns a RegexMatch object containing the match or nothing if the match failed.

例子：

# Julia program to illustrate 
# the use of match() method
   
# Getting a RegexMatch object containing
# the match or nothing if the match failed. 
R = r"G(.)G"
println(match(R, "GFG"))
println(match(R, "Geeks"))
println(match(R, "gfgGfG"))
println(match(R, "GFG", 1))
println(match(R, "GFG", 2))

输出：

RegexMatch("GFG", 1="F")
nothing
RegexMatch("GfG", 1="f")
RegexMatch("GFG", 1="F")
nothing

每个匹配（）

eachmatch()是 julia 中的内置函数，用于在指定字符串s中搜索给定正则表达式r的所有匹配项，然后返回匹配项的迭代器。如果重叠为真，则允许匹配序列与原始字符串中的索引重叠，否则它们必须来自不同的字符范围。

Syntax:
eachmatch(r::Regex, s::AbstractString; overlap::Bool)

Parameters:

• r::Regex: Specified regular expression.
• s::AbstractString: Specified string.
• overlap::Bool: Specified overlap boolean value.

Returns: It returns a iterator over the matches.

例子：

# Julia program to illustrate 
# the use of eachmatch() method
   
# Getting a iterator over the matches
R = r"G(.)G"
println(eachmatch(R, "GFG"))
println(eachmatch(R, "GeeksforGeeks"))
println(eachmatch(R, "Geeks"))
println(eachmatch(R, "GFG", overlap = true))
println(collect(eachmatch(R, "GFGGfGGeekGeeks", overlap = true)))

输出：