在 NSIS 的电子邮件有效性插件中，有一个脚本很好奇其意图或含义

Question

nsh脚本如下。

我对 lbl_check 部分以及在 CheckUserEmailAddress 函数内部第四行开始的函数内声明宏的部分感到好奇。

宏在定义之前调用(!insertmacro)可以吗？

另外，lbl_check2~5部分会依次进行吗？

Function CheckUserEmailAddress
 
    !define CheckUserEmailAddress "!insertmacro CheckUserEmailAddressCall"
 
    !macro CheckUserEmailAddressCall _INPUT _RESULT
    Push "${_INPUT}"
    Call CheckUserEmailAddress
    Pop ${_RESULT}
    !macroend
 
    Exch $R0
    Push $R1
    Push $R2
    Push $R3
    Push $R4
    Push $R5
 
    #count the number of @'s more than one is invalid, less than one is invalid
    ${WordFind} "$R0" "@" "*" $R1
    StrCmp "1" "$R1" lbl_check2 lbl_error
 
 lbl_check2:
    #count the number of words delimited by @ it should be 2.
    ${WordFind} "$R0" "@" "#" $R1
    StrCmp "2" "$R1" lbl_check3 lbl_error
 
 lbl_check3:
    #Split the words into user and domain
    ${WordFind} "$R0" "@" "+1" $R2
    ${WordFind} "$R0" "@" "-1" $R3
    #Determine if either of the fields contain special RFC822 characters
    ${StrFilter} "$R2" "" "" '()<>,;:\"[]' $R1
    StrCmp "$R2" "$R1" 0 lbl_error
    ${StrFilter} "$R3" "" "" '()<>,;:\"[]' $R1
    StrCmp "$R3" "$R1" lbl_check4 lbl_error
 
 lbl_check4:
    #Determine the number of fields in user and domain, check to see
    #the number of delimiter is one less than the number of words.
    StrCpy $R4 0
    StrCpy $R5 0
    ${WordFind} "$R2" "." "*" $R4
    ${WordFind} "$R2" "." "#" $R5
 
    StrCmp "$R4" "$R2" lbl_check5
    StrCmp "$R5" "$R2" lbl_check5
 
    IntOp $R4 $R4 + 1
    StrCmp "$R4" "$R5" 0 lbl_error
 
 lbl_check5:  
    StrCpy $R4 0
    StrCpy $R5 0    
    ${WordFind} "$R3" "." "*" $R4
    ${WordFind} "$R3" "." "#" $R5
 
    StrCmp "$R3" "$R4" lbl_error
    StrCmp "$R3" "$R5" lbl_error
 
    IntOp $R4 $R4 + 1
    StrCmp "$R4" "$R5" 0 lbl_error
 
 ; Unused label? lbl_check6:
    # make sure there is at least one "." in the domain section.
    ${WordFind} "$R3" "." "*" $R1
    IntCmp 1 $R1 lbl_end lbl_end lbl_error
    StrCpy $R0 0
 
 lbl_error:
    StrCpy $R0 1
 
 lbl_end:
    Pop $R5
    Pop $R4
    Pop $R3
    Pop $R2
    Pop $R1
    Exch $R0
FunctionEnd
 
!endif

---

Q1) 有没有理由从下面的 !define 中一一重新定义!宏？

Function CheckUserEmailAddress

    !define CheckUserEmailAddress "!insertmacro CheckUserEmailAddressCall"

    !macro CheckUserEmailAddressCall _INPUT _RESULT

---

Q2)

lbl_check2~5, lbl_error, end

这是一个 switch-case 短语吗？

Answer 1

!define CheckUserEmailAddress "!insertmacro CheckUserEmailAddressCall"

不会调用任何东西，它只是用户避免输入 !insertmacro 的助手。

Section
${CheckUserEmailAddress} foo bar
SectionEnd

只是扩展到

Section
!insertmacro CheckUserEmailAddressCall foo bar
SectionEnd

扩展到

Section
Push foo
Call CheckUserEmailAddress
Pop bar
SectionEnd

---

标签是按顺序进行的，不是开关。