Why does this regex not match decimal numbers?

bbneo 0
Viewed 45
([.[:digit:]]+)

I am thinking this should match decimal numbers like 25.8 or 0.6 ..., but it seems to give up at the "non-digit" part of the match... so I only get 25 or 0

I have tried to escape the "." with \. and . I am doing this in R, using gregexpr().

Here is a minimal reproducible example:

test
[1] "  UNITS\n  LAB             6690-2(LOINC) WBC # Bld Auto 10.99       "

LABregexlabname
[1] "LAB[[:print:][:blank:]]+WBC[[:print:][:blank:]]+([\\.[:digit:]]+)[:blank:]*?"

> gregexpr( LABregexlabname, test)
[[1]]
[1] 11
attr(,"match.length")
[1] 46
attr(,"index.type")
[1] "chars"
attr(,"useBytes")
[1] TRUE

substring( test, 11, 11+46)
[1] "LAB             6690-2(LOINC) WBC # Bld Auto 10"
r numbers regex
1 Answers

Place the last [:blank:] inside [] as [[:blank:]] and use perl=TRUE.

test <- "  UNITS\n  LAB             6690-2(LOINC) WBC # Bld Auto 10.99       "
LABregexlabname <- "LAB[[:print:][:blank:]]+WBC[[:print:][:blank:]]+([.[:digit:]]+)[[:blank:]]*?"

regmatches(test, regexpr(LABregexlabname, test, perl=TRUE))
#[1] "LAB             6690-2(LOINC) WBC # Bld Auto 10.99"

It looks like TRE uses minimal match everywhere when using ? at the end. In this case, when removing the ? also TRE will give the whole number but also all spaces. So maybe leaving also [[:blank:]]* ?

LABregexlabname <- "LAB[[:print:][:blank:]]+WBC[[:print:][:blank:]]+([.[:digit:]]+)[[:blank:]]*"
regmatches(test, regexpr(LABregexlabname, test))
#[1] "LAB             6690-2(LOINC) WBC # Bld Auto 10.99       "

LABregexlabname <- "LAB[[:print:][:blank:]]+WBC[[:print:][:blank:]]+([.[:digit:]]+)"
regmatches(test, regexpr(LABregexlabname, test))
#[1] "LAB             6690-2(LOINC) WBC # Bld Auto 10.99"
GKi0
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