Dependencies can now be specified.

version.nim

@@ -0,0 +1,183 @@
+## Module for handling versions and version ranges such as ``>= 1.0 & <= 1.5``
+import strutils
+type
+  TVersion* = distinct string
+
+  TVersionRangeEnum* = enum
+    verLater, # > V
+    verEarlier, # < V
+    verEqLater, # >= V -- Equal or later
+    verEqEarlier, # <= V -- Equal or earlier
+    verIntersect, # > V & < V
+    verEq, # V
+    verAny # *
+
+  PVersionRange* = ref TVersionRange
+  TVersionRange* = object
+    case kind*: TVersionRangeEnum
+    of verLater, verEarlier, verEqLater, verEqEarlier, verEq:
+      ver*: TVersion
+    of verIntersect:
+      verILeft, verIRight: PVersionRange
+    of verAny:
+      nil
+
+  EParseVersion* = object of EInvalidValue
+
+proc newVersion*(ver: string): TVersion = return TVersion(ver)
+
+proc `$`*(ver: TVersion): String {.borrow.}
+
+proc `<`*(ver: TVersion, ver2: TVersion): Bool =
+  var sVer = string(ver).split('.')
+  var sVer2 = string(ver2).split('.')
+  for i in 0..max(sVer.len, sVer2.len)-1:
+    if i > sVer.len-1:
+      return True
+    elif i > sVer2.len-1:
+      return False
+
+    var sVerI = parseInt(sVer[i])
+    var sVerI2 = parseInt(sVer2[i])
+    if sVerI < sVerI2:
+      return True
+    elif sVerI == sVerI2:
+      nil
+    else:
+      return False
+
+proc `==`*(ver: TVersion, ver2: TVersion): Bool {.borrow.}
+
+proc `<=`*(ver: TVersion, ver2: TVersion): Bool =
+  return (ver == ver2) or (ver < ver2)
+
+proc withinRange*(ver: TVersion, ran: PVersionRange): Bool =
+  case ran.kind
+  of verLater:
+    return ver > ran.ver
+  of verEarlier:
+    return ver < ran.ver
+  of verEqLater:
+    return ver >= ran.ver
+  of verEqEarlier:
+    return ver <= ran.ver
+  of verEq:
+    return ver == ran.ver
+  of verIntersect:
+    return withinRange(ver, ran.verILeft) and withinRange(ver, ran.verIRight)
+  of verAny:
+    return True
+
+proc makeRange*(version: string, op: string): PVersionRange =
+  new(result)
+  if version == "":
+    raise newException(EParseVersion, "A version needs to accompany the operator.")
+  case op
+  of ">":
+    result.kind = verLater
+  of "<":
+    result.kind = verEarlier
+  of ">=":
+    result.kind = verEqLater
+  of "<=":
+    result.kind = verEqEarlier
+  of "":
+    result.kind = verEq
+  else:
+    raise newException(EParseVersion, "Invalid operator: " & op)
+  result.ver = TVersion(version)
+
+proc parseVersionRange*(s: string): PVersionRange =
+  # >= 1.5 & <= 1.8
+  new(result)
+
+  var i = 0
+  var op = ""
+  var version = ""
+  while True:
+    case s[i]
+    of '>', '<', '=':
+      op.add(s[i])
+    of '&':
+      result.kind = verIntersect
+      result.verILeft = makeRange(version, op)
+      
+      # Parse everything after &
+      # Recursion <3
+      result.verIRight = parseVersionRange(substr(s, i + 1))
+
+      # Disallow more than one verIntersect. It's pointless and could lead to
+      # major unknown mistakes.
+      if result.verIRight.kind == verIntersect:
+        raise newException(EParseVersion,
+            "Having more than one `&` in a version range is pointless")
+      
+      break
+
+    of '0'..'9', '.':
+      version.add(s[i])
+
+    of '\0':
+      result = makeRange(version, op)
+      break
+    
+    of ' ':
+      # Make sure '0.9 8.03' is not allowed.
+      if version != "" and i < s.len:
+        if s[i+1] in {'0'..'9', '.'}:
+          raise newException(EParseVersion, "Whitespace is not allowed in a version literal.")
+
+    else:
+      raise newException(EParseVersion, "Unexpected char in version range: " & s[i])
+    inc(i)
+
+proc `$`*(verRange: PVersionRange): String =
+  echo(verRange.repr())
+  case verRange.kind
+  of verLater:
+    result = "> "
+  of verEarlier:
+    result = "< "
+  of verEqLater:
+    result = ">= "
+  of verEqEarlier:
+    result = "<= "
+  of verEq:
+    result = ""
+  of verIntersect:
+    return $verRange.verILeft & " & " & $verRange.verIRight
+  of verAny:
+    return "Any"
+
+  result.add(string(verRange.ver))
+
+proc newVRAny*(): PVersionRange =
+  new(result)
+  result.kind = verAny
+
+proc newVREarlier*(ver: String): PVersionRange =
+  new(result)
+  result.kind = verEarlier
+  result.ver = newVersion(ver)
+
+proc newVREq*(ver: string): PVersionRange =
+  new(result)
+  result.kind = verEq
+  result.ver = newVersion(ver)
+
+when isMainModule:
+  doAssert(newVersion("1.0") < newVersion("1.4"))
+  doAssert(newVersion("1.0.1") > newVersion("1.0"))
+  doAssert(newVersion("1.0.6") <= newVersion("1.0.6"))
+
+  var inter1 = parseVersionRange(">= 1.0 & <= 1.5")
+  var inter2 = parseVersionRange("1.0")
+  doAssert(inter2.kind == verEq)
+  #echo(parseVersionRange(">= 0.8 0.9"))
+
+  doAssert(not withinRange(newVersion("1.5.1"), inter1))
+  doAssert(withinRange(newVersion("1.0.2.3.4.5.6.7.8.9.10.11.12"), inter1))
+
+  doAssert(newVersion("1") == newVersion("1"))
+
+  echo("Everything works!")