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#
#
# The Nim Compiler
# (c) Copyright 2018 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
## Path handling utilities for Nim. Strictly typed code in order
## to avoid the never ending time sink in getting path handling right.
## Might be a candidate for the stdlib later.
import os, strutils
type
AbsoluteFile* = distinct string
AbsoluteDir* = distinct string
RelativeFile* = distinct string
RelativeDir* = distinct string
proc isEmpty*(x: AbsoluteFile): bool {.inline.} = x.string.len == 0
proc isEmpty*(x: AbsoluteDir): bool {.inline.} = x.string.len == 0
proc isEmpty*(x: RelativeFile): bool {.inline.} = x.string.len == 0
proc isEmpty*(x: RelativeDir): bool {.inline.} = x.string.len == 0
proc copyFile*(source, dest: AbsoluteFile) =
os.copyFile(source.string, dest.string)
proc removeFile*(x: AbsoluteFile) {.borrow.}
proc splitFile*(x: AbsoluteFile): tuple[dir: AbsoluteDir, name, ext: string] =
let (a, b, c) = splitFile(x.string)
result = (dir: AbsoluteDir(a), name: b, ext: c)
proc extractFilename*(x: AbsoluteFile): string {.borrow.}
proc fileExists*(x: AbsoluteFile): bool {.borrow.}
proc dirExists*(x: AbsoluteDir): bool {.borrow.}
proc quoteShell*(x: AbsoluteFile): string {.borrow.}
proc quoteShell*(x: AbsoluteDir): string {.borrow.}
proc cmpPaths*(x, y: AbsoluteDir): int {.borrow.}
proc createDir*(x: AbsoluteDir) {.borrow.}
type
PathIter = object
i, prev: int
notFirst: bool
proc hasNext(it: PathIter; x: string): bool =
it.i < x.len
proc next(it: var PathIter; x: string): (int, int) =
it.prev = it.i
if not it.notFirst and x[it.i] in {DirSep, AltSep}:
# absolute path:
inc it.i
else:
while it.i < x.len and x[it.i] notin {DirSep, AltSep}: inc it.i
if it.i > it.prev:
result = (it.prev, it.i-1)
elif hasNext(it, x):
result = next(it, x)
# skip all separators:
while it.i < x.len and x[it.i] in {DirSep, AltSep}: inc it.i
it.notFirst = true
iterator dirs(x: string): (int, int) =
var it: PathIter
while hasNext(it, x): yield next(it, x)
proc isDot(x: string; bounds: (int, int)): bool =
bounds[1] == bounds[0] and x[bounds[0]] == '.'
proc isDotDot(x: string; bounds: (int, int)): bool =
bounds[1] == bounds[0] + 1 and x[bounds[0]] == '.' and x[bounds[0]+1] == '.'
proc isSlash(x: string; bounds: (int, int)): bool =
bounds[1] == bounds[0] and x[bounds[0]] in {DirSep, AltSep}
const canonDirSep = when isMainModule: '/' else: DirSep
proc canon(x: string; result: var string; state: var int) =
# state: 0th bit set if isAbsolute path. Other bits count
# the number of path components.
for b in dirs(x):
if (state shr 1 == 0) and isSlash(x, b):
result.add canonDirSep
state = state or 1
elif result.len > (state and 1) and isDotDot(x, b):
var d = result.len
# f/..
while (d-1) > (state and 1) and result[d-1] notin {DirSep, AltSep}:
dec d
if d > 0: setLen(result, d-1)
elif isDot(x, b):
discard "discard the dot"
elif b[1] >= b[0]:
if result.len > 0 and result[^1] notin {DirSep, AltSep}:
result.add canonDirSep
result.add substr(x, b[0], b[1])
inc state, 2
proc canon(x: string): string =
# - Turn multiple slashes into single slashes.
# - Resolve '/foo/../bar' to '/bar'.
# - Remove './' from the path.
result = newStringOfCap(x.len)
var state = 0
canon(x, result, state)
when FileSystemCaseSensitive:
template `!=?`(a, b: char): bool = toLowerAscii(a) != toLowerAscii(b)
else:
template `!=?`(a, b: char): bool = a != b
proc relativeTo(full, base: string; sep = canonDirSep): string =
if full.len == 0: return ""
var f, b: PathIter
var ff = (0, -1)
var bb = (0, -1) # (int, int)
result = newStringOfCap(full.len)
# skip the common prefix:
while f.hasNext(full) and b.hasNext(base):
ff = next(f, full)
bb = next(b, base)
let diff = ff[1] - ff[0]
if diff != bb[1] - bb[0]: break
var same = true
for i in 0..diff:
if full[i + ff[0]] !=? base[i + bb[0]]:
same = false
break
if not same: break
ff = (0, -1)
bb = (0, -1)
# for i in 0..diff:
# result.add base[i + bb[0]]
# /foo/bar/xxx/ -- base
# /foo/bar/baz -- full path
# ../baz
# every directory that is in 'base', needs to add '..'
while true:
if bb[1] >= bb[0]:
if result.len > 0 and result[^1] != sep:
result.add sep
result.add ".."
if not b.hasNext(base): break
bb = b.next(base)
# add the rest of 'full':
while true:
if ff[1] >= ff[0]:
if result.len > 0 and result[^1] != sep:
result.add sep
for i in 0..ff[1] - ff[0]:
result.add full[i + ff[0]]
if not f.hasNext(full): break
ff = f.next(full)
when true:
proc eqImpl(x, y: string): bool =
when FileSystemCaseSensitive:
result = cmpIgnoreCase(canon x, canon y) == 0
else:
result = canon(x) == canon(y)
proc `==`*(x, y: AbsoluteFile): bool = eqImpl(x.string, y.string)
proc `==`*(x, y: AbsoluteDir): bool = eqImpl(x.string, y.string)
proc `==`*(x, y: RelativeFile): bool = eqImpl(x.string, y.string)
proc `==`*(x, y: RelativeDir): bool = eqImpl(x.string, y.string)
proc `/`*(base: AbsoluteDir; f: RelativeFile): AbsoluteFile =
#assert isAbsolute(base.string)
assert(not isAbsolute(f.string))
result = AbsoluteFile newStringOfCap(base.string.len + f.string.len)
var state = 0
canon(base.string, result.string, state)
canon(f.string, result.string, state)
proc `/`*(base: AbsoluteDir; f: RelativeDir): AbsoluteDir =
#assert isAbsolute(base.string)
assert(not isAbsolute(f.string))
result = AbsoluteDir newStringOfCap(base.string.len + f.string.len)
var state = 0
canon(base.string, result.string, state)
canon(f.string, result.string, state)
proc relativeTo*(fullPath: AbsoluteFile, baseFilename: AbsoluteDir;
sep = canonDirSep): RelativeFile =
RelativeFile(relativeTo(fullPath.string, baseFilename.string, sep))
proc toAbsolute*(file: string; base: AbsoluteDir): AbsoluteFile =
if isAbsolute(file): result = AbsoluteFile(file)
else: result = base / RelativeFile file
proc changeFileExt*(x: AbsoluteFile; ext: string): AbsoluteFile {.borrow.}
proc changeFileExt*(x: RelativeFile; ext: string): RelativeFile {.borrow.}
proc addFileExt*(x: AbsoluteFile; ext: string): AbsoluteFile {.borrow.}
proc addFileExt*(x: RelativeFile; ext: string): RelativeFile {.borrow.}
proc writeFile*(x: AbsoluteFile; content: string) {.borrow.}
when isMainModule:
doAssert canon"/foo/../bar" == "/bar"
doAssert canon"foo/../bar" == "bar"
doAssert canon"/f/../bar///" == "/bar"
doAssert canon"f/..////bar" == "bar"
doAssert canon"../bar" == "../bar"
doAssert canon"/../bar" == "/../bar"
doAssert canon("foo/../../bar/") == "../bar"
doAssert canon("./bla/blob/") == "bla/blob"
doAssert canon(".hiddenFile") == ".hiddenFile"
doAssert canon("./bla/../../blob/./zoo.nim") == "../blob/zoo.nim"
doAssert canon("C:/file/to/this/long") == "C:/file/to/this/long"
doAssert canon("") == ""
doAssert canon("foobar") == "foobar"
doAssert canon("f/////////") == "f"
doAssert relativeTo("/foo/bar//baz.nim", "/foo") == "bar/baz.nim"
doAssert relativeTo("/Users/me/bar/z.nim", "/Users/other/bad") == "../../me/bar/z.nim"
doAssert relativeTo("/Users/me/bar/z.nim", "/Users/other") == "../me/bar/z.nim"
doAssert relativeTo("/Users///me/bar//z.nim", "//Users/") == "me/bar/z.nim"
doAssert relativeTo("/Users/me/bar/z.nim", "/Users/me") == "bar/z.nim"
doAssert relativeTo("", "/users/moo") == ""
doAssert relativeTo("foo", "") == "foo"
doAssert AbsoluteDir"/Users/me///" / RelativeFile"z.nim" == AbsoluteFile"/Users/me/z.nim"
doAssert relativeTo("/foo/bar.nim", "/foo/") == "bar.nim"
when isMainModule and defined(windows):
let nasty = string(AbsoluteDir(r"C:\Users\rumpf\projects\nim\tests\nimble\nimbleDir\linkedPkgs\pkgB-#head\../../simplePkgs/pkgB-#head/") / RelativeFile"pkgA/module.nim")
doAssert nasty.replace('/', '\\') == r"C:\Users\rumpf\projects\nim\tests\nimble\nimbleDir\simplePkgs\pkgB-#head\pkgA\module.nim"
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