(Visual FoxPro) Regular Expression with Multiple Matches and Named Capture Groups

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Note: This example requires Chilkat v11.1.0 or greater.

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LOCAL lnSuccess
LOCAL loSb
LOCAL lnCrlf
LOCAL lcPattern
LOCAL loJson
LOCAL lnTimeoutMs
LOCAL lnNumMatches
LOCAL lnIdx_first
LOCAL lnIdx_last
LOCAL i
LOCAL lnMatchCount

lnSuccess = 0

loSb = CreateObject('Chilkat.StringBuilder')
lnCrlf = 1
loSb.AppendLine("Name: John Smith",lnCrlf)
loSb.AppendLine("Name: Jack Johnson",lnCrlf)
loSb.AppendLine("Name: Mary Adams",lnCrlf)

? loSb.GetAsString()

* We have the following string:
* Name: John Smith
* Name: Jack Johnson
* Name: Mary Adams

lcPattern = "Name:\s+(?<first>\w+)\s+(?<last>\w+)"
loJson = CreateObject('Chilkat.JsonObject')
loJson.EmitCompact = 0

lnTimeoutMs = 2000
lnNumMatches = loSb.RegexMatch(lcPattern,loJson,lnTimeoutMs)
IF (lnNumMatches < 0) THEN
    * Probably an error in the regular expression.
    * Suggestion: Use AI to help create and/or diagnose regular expressions.
    ? loSb.LastErrorText
    RELEASE loSb
    RELEASE loJson
    CANCEL
ENDIF

* Examine the matches:
? loJson.Emit()

* Here is the JSON showing the matches.
* Important:  Capture group 0 always contains the entire match — that is, the portion of the input string that matches the full regular expression.

* {
*   "named": {
*     "first": 1,
*     "last": 2
*   },
*   "match": [
*     {
*       "group": [
*         {
*           "cap": "Name: John Smith",
*           "idx": 0,
*           "len": 16
*         },
*         {
*           "cap": "John",
*           "idx": 6,
*           "len": 4
*         },
*         {
*           "cap": "Smith",
*           "idx": 11,
*           "len": 5
*         }
*       ]
*     },
*     {
*       "group": [
*         {
*           "cap": "Name: Jack Johnson",
*           "idx": 18,
*           "len": 18
*         },
*         {
*           "cap": "Jack",
*           "idx": 24,
*           "len": 4
*         },
*         {
*           "cap": "Johnson",
*           "idx": 29,
*           "len": 7
*         }
*       ]
*     },
*     {
*       "group": [
*         {
*           "cap": "Name: Mary Adams",
*           "idx": 38,
*           "len": 16
*         },
*         {
*           "cap": "Mary",
*           "idx": 44,
*           "len": 4
*         },
*         {
*           "cap": "Adams",
*           "idx": 49,
*           "len": 5
*         }
*       ]
*     }
*   ]
* }

* The capture group index is obtained by looking up the name in the JSON result.
* For example:

lnIdx_first = loJson.IntOf("named.first")
lnIdx_last = loJson.IntOf("named.last")

i = 0
lnMatchCount = loJson.SizeOfArray("match")
DO WHILE i < lnMatchCount
    ? "Match " + STR(i + 1) + ":"
    loJson.I = i

    loJson.J = lnIdx_first
    ? "first: " + loJson.StringOf("match[i].group[j].cap")

    loJson.J = lnIdx_last
    ? "first: " + loJson.StringOf("match[i].group[j].cap")

    ? ""
    i = i + 1
ENDDO

* Output is: 

* Match 1:
* first: John
* first: Smith
* 
* Match 2:
* first: Jack
* first: Johnson
* 
* Match 3:
* first: Mary
* first: Adams

RELEASE loSb
RELEASE loJson