ConvertFromRustToPInvoke.ps1

Import-Module PSStringScanner

function ConvertFrom-RustToPInvoke {
    param(
        [Parameter(Mandatory)]
        $DllName,
        [Parameter(Mandatory)]
        $content
    )

    $parseResult = $(foreach ($line in $content) {
        $ss = New-PSStringScanner $line

        if($ss.Check('pub extern "C"')) {
            $null = $ss.ScanUntil('fn ')
            $functionName = $ss.ScanUntil('(?=\()')        
            $null = $ss.Scan("\(")
            $parameters = $ss.ScanUntil('(?=\))')
            $null = $ss.Scan('-> ')        
            $returnType = $ss.ScanUntil('(?= {)')

            #$ss

            $params = foreach ($parameter in $parameters.Split(",")) {
                $Name,$Type = $parameter.Split(':')
    
                [PSCustomObject][Ordered]@{
                    Name=$Name.Trim()
                    Type=$Type.Trim()
                }        
            }

            [PSCustomObject][Ordered]@{
                FunctionName = $functionName            
                Parameters   = $params
                Type   = $returnType
            }
        }
    })

    $RustToCSharpTypeMap= @{
        'i32' = 'Int32'    
    }

    $CSParams = ($parseResult.Parameters | % {
        "{0} {1}" -f ($RustToCSharpTypeMap.($_.Type)), $_.Name
    }) -join ", "


@"
[DllImport("$($dllname)")]
public static extern $($RustToCSharpTypeMap.($parseResult.Type)) $($parseResult.FunctionName)($($CSParams));
"@
}

return 
ConvertFrom-RustToPInvoke -DllName "ps_to_rust" -Content @"
#[no_mangle]
pub extern "C" fn add_numbers(number1: i32, number2: i32) -> i32 {
    number1 + number2
}
"@