annotate vext.ps1 @ 50:ec5b5a9adac2

Overhaul to use Vext for external repos

<#

.SYNOPSIS
A simple manager for third-party source code dependencies.
Run "vext help" for more documentation.

#>

$sml = $env:VEXT_SML

$mydir = Split-Path $MyInvocation.MyCommand.Path -Parent
$program = "$mydir/vext.sml"

# We need either Poly/ML or SML/NJ. No great preference as to which.

if (!$sml) {
    if (Get-Command "polyml" -ErrorAction SilentlyContinue) {
       $sml = "poly"
    } elseif (Get-Command "sml" -ErrorAction SilentlyContinue) {
       $sml = "smlnj"
    } else {
       echo @"

ERROR: No supported SML compiler or interpreter found       

  The Vext external source code manager needs a Standard ML (SML)
  compiler or interpreter to run.

  Please ensure you have one of the following SML implementations
  installed and present in your PATH, and try again.

    1. Poly/ML
       - executable name: polyml

    2. Standard ML of New Jersey
       - executable name: sml

"@
       exit 1
    }
}

if ($args -match "[^a-z]") {
    $arglist = '["usage"]'
} else {
    $arglist = '["' + ($args -join '","') + '"]'
}

if ($sml -eq "poly") {

    $program = $program -replace "\\","\\\\"
    echo "use ""$program""; vext $arglist" | polyml -q --error-exit | Out-Host

} elseif ($sml -eq "smlnj") {

    $lines = @(Get-Content $program)
    $lines = $lines -notmatch "val _ = main ()"

    $intro = @"
val smlrun__cp = 
    let val x = !Control.Print.out in
        Control.Print.out := { say = fn _ => (), flush = fn () => () };
        x
    end;
val smlrun__prev = ref "";
Control.Print.out := { 
    say = fn s => 
        (if String.isSubstring "Error" s orelse String.isSubstring "Fail" s
         then (Control.Print.out := smlrun__cp;
               (#say smlrun__cp) (!smlrun__prev);
               (#say smlrun__cp) s)
         else (smlrun__prev := s; ())),
    flush = fn s => ()
};
"@ -split "[\r\n]+"

   $outro = @"
val _ = vext $arglist;
val _ = OS.Process.exit (OS.Process.success);
"@ -split "[\r\n]+"

   $script = @()
   $script += $intro
   $script += $lines
   $script += $outro

   $tmpfile = ([System.IO.Path]::GetTempFileName()) -replace "[.]tmp",".sml"

   $script | Out-File -Encoding "ASCII" $tmpfile

   $env:CM_VERBOSE="false"

   sml $tmpfile $args[1,$args.Length]

   del $tmpfile

} else {

   "Unknown SML implementation name: $sml"
   exit 2
}