cuelang.org/go@v0.10.1/cue/examples_test.go (about)

     1  // Copyright 2021 CUE Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package cue_test
    16  
    17  import (
    18  	"fmt"
    19  	"log"
    20  	"os"
    21  
    22  	"cuelang.org/go/cue"
    23  	"cuelang.org/go/cue/cuecontext"
    24  	"cuelang.org/go/internal/cuetxtar"
    25  	"golang.org/x/tools/txtar"
    26  )
    27  
    28  func load(file string) *cue.Instance {
    29  	dir, _ := os.MkdirTemp("", "*")
    30  	defer os.RemoveAll(dir)
    31  
    32  	inst := cue.Build(cuetxtar.Load(txtar.Parse([]byte(file)), dir))[0]
    33  	if err := inst.Err; err != nil {
    34  		panic(err)
    35  	}
    36  	return inst
    37  }
    38  
    39  func ExampleHid() {
    40  	const file = `
    41  -- cue.mod/module.cue --
    42  module: "mod.test"
    43  language: version: "v0.9.0"
    44  
    45  -- main.cue --
    46  import "mod.test/foo:bar"
    47  
    48  bar
    49  _foo: int // scoped in main (anonymous) package
    50  baz: _foo
    51  
    52  -- foo/bar.cue --
    53  package bar
    54  
    55  _foo: int // scoped within imported package
    56  bar: _foo
    57  `
    58  
    59  	v := load(file).Value()
    60  
    61  	v = v.FillPath(cue.MakePath(cue.Hid("_foo", "mod.test/foo:bar")), 1)
    62  	v = v.FillPath(cue.MakePath(cue.Hid("_foo", "_")), 2)
    63  	fmt.Println(v.LookupPath(cue.ParsePath("bar")).Int64())
    64  	fmt.Println(v.LookupPath(cue.ParsePath("baz")).Int64())
    65  
    66  	// Output:
    67  	// 1 <nil>
    68  	// 2 <nil>
    69  }
    70  
    71  func ExampleValue_Allows() {
    72  	ctx := cuecontext.New()
    73  
    74  	const file = `
    75  a: [1, 2, ...int]
    76  
    77  b: #Point
    78  #Point: {
    79  	x:  int
    80  	y:  int
    81  	z?: int
    82  }
    83  
    84  c: [string]: int
    85  
    86  d: #C
    87  #C: [>"m"]: int
    88  `
    89  
    90  	v := ctx.CompileString(file)
    91  	if err := v.Err(); err != nil {
    92  		log.Fatal(err)
    93  	}
    94  
    95  	a := v.LookupPath(cue.ParsePath("a"))
    96  	fmt.Println("a allows:")
    97  	fmt.Println("  index 4:       ", a.Allows(cue.Index(4)))
    98  	fmt.Println("  any index:     ", a.Allows(cue.AnyIndex))
    99  	fmt.Println("  any string:    ", a.Allows(cue.AnyString))
   100  
   101  	b := v.LookupPath(cue.ParsePath("b"))
   102  	fmt.Println("b allows:")
   103  	fmt.Println("  field x:       ", b.Allows(cue.Str("x")))
   104  	fmt.Println("  field z:       ", b.Allows(cue.Str("z")))
   105  	fmt.Println("  field foo:     ", b.Allows(cue.Str("foo")))
   106  	fmt.Println("  index 4:       ", b.Allows(cue.Index(4)))
   107  	fmt.Println("  any string:    ", b.Allows(cue.AnyString))
   108  
   109  	c := v.LookupPath(cue.ParsePath("c"))
   110  	fmt.Println("c allows:")
   111  	fmt.Println("  field z:       ", c.Allows(cue.Str("z")))
   112  	fmt.Println("  field foo:     ", c.Allows(cue.Str("foo")))
   113  	fmt.Println("  index 4:       ", c.Allows(cue.Index(4)))
   114  	fmt.Println("  any string:    ", c.Allows(cue.AnyString))
   115  
   116  	d := v.LookupPath(cue.ParsePath("d"))
   117  	fmt.Println("d allows:")
   118  	fmt.Println("  field z:       ", d.Allows(cue.Str("z")))
   119  	fmt.Println("  field foo:     ", d.Allows(cue.Str("foo")))
   120  	fmt.Println("  index 4:       ", d.Allows(cue.Index(4)))
   121  	fmt.Println("  any string:    ", d.Allows(cue.AnyString))
   122  
   123  	// Output:
   124  	// a allows:
   125  	//   index 4:        true
   126  	//   any index:      true
   127  	//   any string:     false
   128  	// b allows:
   129  	//   field x:        true
   130  	//   field z:        true
   131  	//   field foo:      false
   132  	//   index 4:        false
   133  	//   any string:     false
   134  	// c allows:
   135  	//   field z:        true
   136  	//   field foo:      true
   137  	//   index 4:        false
   138  	//   any string:     true
   139  	// d allows:
   140  	//   field z:        true
   141  	//   field foo:      false
   142  	//   index 4:        false
   143  	//   any string:     false
   144  }