removePrefix

lib.path.removePrefix

Docs pulled from | This Revision | 10 minutes ago

Remove the first path as a component-wise prefix from the second path. The result is a normalised subpath string.

Laws:

Inverts append for normalised subpath string:

removePrefix p (append p s) == subpath.normalise s

Inputs

path1: 1. Function argument

Type

removePrefix :: Path -> Path -> String

Examples

`removePrefix` usage example

removePrefix /foo /foo/bar/baz
=> "./bar/baz"
removePrefix /foo /foo
=> "./."
removePrefix /foo/bar /foo
=> <error>
removePrefix /. /foo
=> "./foo"

Noogle detected

Implementation

The following is the current implementation of this function.

removePrefix =
    path1:
    assert assertMsg (isPath path1)
      "lib.path.removePrefix: First argument is of type ${typeOf path1}, but a path was expected.";
    let
      path1Deconstructed = deconstructPath path1;
      path1Length = length path1Deconstructed.components;
    in
    path2:
    assert assertMsg (isPath path2)
      "lib.path.removePrefix: Second argument is of type ${typeOf path2}, but a path was expected.";
    let
      path2Deconstructed = deconstructPath path2;
      success = take path1Length path2Deconstructed.components == path1Deconstructed.components;
      components =
        if success then
          drop path1Length path2Deconstructed.components
        else
          throw ''lib.path.removePrefix: The first path argument "${toString path1}" is not a component-wise prefix of the second path argument "${toString path2}".'';
    in
    assert assertMsg (path1Deconstructed.root == path2Deconstructed.root) ''
      lib.path.removePrefix: Filesystem roots must be the same for both paths, but paths with different roots were given:
          first argument: "${toString path1}" with root "${toString path1Deconstructed.root}"
          second argument: "${toString path2}" with root "${toString path2Deconstructed.root}"'';
    joinRelPath components;