structural

Structural diff, merge, patch, pick, and mask helpers for CUE.

MVS will make using cue modules easier.

Index

support for both Cue and Go vals/structs

1. Usage
2. equal
3. diff
4. merge
5. patch
6. pick
7. mask
8. Developing

Usage

structural is most easily used with cue modules, see https://github.com/hofstadter-io/mvs.

Initialize a cue module

mvs init cue github.com/<namespace>/<project>

Add structural to your cue.mods file:

require github.com/hofstadter-io/structural v0.0.3

Update your dependencies:

mvs vendor

After creating example.cue (see below) run the following:

cue eval example.cue
cue export example.cue

Look for a "same" field == true

example.cue

import "github.com/hofstadter-io/structural"

A :: {
	a: "a"
	b: "b"
	N: {x: "x", y: "y"}
}
B :: {
	b: "b"
	c: "c"
	N: {x: "x", z: "z"}
}

diff: {
  same: (ex & an) != _|_
  ex: (structural.Diff & {Orig: A, New: B}).Result
  an: {
    "[]": {
      removed: {
        a: "a"
      }
      added: {
        c: "c"
      }
    }
    "[\"N\"]": {
      removed: {
        y: "y"
      }
      added: {
        z: "z"
      }
    }
  }
}

merge: {
  same: (ex & an) != _|_
  ex: (structural.Merge & {Orig: A, New: B}).Result
  an: {
    a: "a"
    b: "b"
    c: "c"
    N: {
      x: "x"
      y: "y"
      z: "z"
    }
  }
}

Diff

Diff :: {
	// Arguments
	Orig: {...}
	New:  {...}

	Result: {...}
}

A :: {
	a: "a"
	b: "b"
	N: {x: "x", y: "y"}
}
Z :: {
	a: "a"
	b: "b"
	N: "N"
}
x: (structural.Diff & {Orig: A, New: Z}).Result
x: {
	changed: {
	  N: {
	    from: {
	      x: "x"
	      y: "y"
	    }
	    to: "N"
	  }
	}
}

Merge

Merge :: {
	// Arguments
	Orig: {...}
	New:  {...}

	Result: {...}

A :: {
	a: "a"
	b: "b"
	N: {x: "x", y: "y"}
}
B :: {
	b: "b"
	c: "c"
	N: {x: "x", z: "z"}
}
x: (structural.Merge & {Orig: A, New: B}).Result
x: {
  a: "a"
  b: "b"
  c: "c"
  N: {
    x: "x"
    y: "y"
    z: "z"
  }
}

Patch

Patch :: {
	// Arguments
	Orig: {...}
	Diff: {...}

	Result: {...}
}

x: (structural.Patch & {Orig: {a: "a", b: "b", y: "y", N: {x: "x"}},
												 Diff: {inplace: {N: {changed: {x: {from: "x", to: "xx"}}}}, changed: {y: {from: "y", to: "yy"}}, removed: {b: "b"}, added: {z: "z"}}}).Result
x: {a: "a", y: "yy", N: {x: "xx"}, z: "z"}

Pick

Pick :: {
	// Arguments
  Orig: {...}
  Pick: {...}

  Result: {...}
}

X:: {
	a: "a"
	b: "b"
	N: {x: "x", y: "y"}
	l: [1, 2, 3, 4, 5]
}
x: (structural.Pick & {Orig: X, Pick: { b: string, N: {x: string}, l: [1, 1, 3] }}).Result
x: {
  b: "b"
  N: {
    x: "x"
  }
  l: [1, 3]
}

Mask

Mask :: {
	// Arguments
  Orig: {...}
  Mask: {...}

  Result: {...}
}

X:: {
	a: "a"
	b: "b"
	N: {x: "x", y: "y"}
	l: [1, 2, 3, 4, 5]
}
x: (structural.Mask & {Orig: X, Mask: { b: string, N: {x: string}, l: [1, 1, 3] }}).Result
x: {
	a: "a"
	N: {
		y: "y"
	}
	l: [2, 4, 5]
}

Developing

There isn't much special, you just need cue installed.

Running tests

cue test

See the test directory for more specifics and examples.

This runs the test command in test_tool.cue which is nothing more than "cue export test/*.cue"