github.com/solo-io/cue@v0.4.7/internal/core/compile/label.go (about)

     1  // Copyright 2020 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 compile
    16  
    17  import (
    18  	"github.com/cockroachdb/apd/v2"
    19  	"golang.org/x/text/unicode/norm"
    20  
    21  	"github.com/solo-io/cue/cue/ast"
    22  	"github.com/solo-io/cue/cue/literal"
    23  	"github.com/solo-io/cue/cue/token"
    24  	"github.com/solo-io/cue/internal/core/adt"
    25  )
    26  
    27  // LabelFromNode converts an ADT node to a feature.
    28  func (c *compiler) label(n ast.Node) adt.Feature {
    29  	index := c.index
    30  	switch x := n.(type) {
    31  	case *ast.Ident:
    32  		return adt.MakeIdentLabel(c.index, x.Name, c.pkgPath)
    33  
    34  	case *ast.BasicLit:
    35  		switch x.Kind {
    36  		case token.STRING:
    37  			const msg = "invalid string label: %v"
    38  			s, err := literal.Unquote(x.Value)
    39  			if err != nil {
    40  				c.errf(n, msg, err)
    41  				return adt.InvalidLabel
    42  			}
    43  
    44  			i := int64(index.StringToIndex(norm.NFC.String(s)))
    45  			f, err := adt.MakeLabel(n, i, adt.StringLabel)
    46  			if err != nil {
    47  				c.errf(n, msg, err)
    48  			}
    49  			return f
    50  
    51  		case token.INT:
    52  			const msg = "invalid int label: %v"
    53  			if err := literal.ParseNum(x.Value, &c.num); err != nil {
    54  				c.errf(n, msg, err)
    55  				return adt.InvalidLabel
    56  			}
    57  
    58  			var d apd.Decimal
    59  			if err := c.num.Decimal(&d); err != nil {
    60  				c.errf(n, msg, err)
    61  				return adt.InvalidLabel
    62  			}
    63  
    64  			i, err := d.Int64()
    65  			if err != nil {
    66  				c.errf(n, msg, err)
    67  				return adt.InvalidLabel
    68  			}
    69  
    70  			f, err := adt.MakeLabel(n, i, adt.IntLabel)
    71  			if err != nil {
    72  				c.errf(n, msg, err)
    73  				return adt.InvalidLabel
    74  			}
    75  			return f
    76  
    77  		case token.FLOAT:
    78  			_ = c.errf(n, "float %s cannot be used as label", x.Value)
    79  			return adt.InvalidLabel
    80  
    81  		default: // keywords (null, true, false, for, in, if, let)
    82  			i := index.StringToIndex(x.Kind.String())
    83  			f, err := adt.MakeLabel(n, i, adt.StringLabel)
    84  			if err != nil {
    85  				c.errf(n, "invalid string label: %v", err)
    86  			}
    87  			return f
    88  		}
    89  
    90  	default:
    91  		c.errf(n, "unsupported label node type %T", n)
    92  		return adt.InvalidLabel
    93  	}
    94  }
    95  
    96  // A labeler converts an AST node to a string representation.
    97  type labeler interface {
    98  	labelString() string
    99  }
   100  
   101  type fieldLabel ast.Field
   102  
   103  func (l *fieldLabel) labelString() string {
   104  	lab := l.Label
   105  
   106  	if a, ok := lab.(*ast.Alias); ok {
   107  		if x, _ := a.Expr.(ast.Label); x != nil {
   108  			lab = x
   109  		}
   110  	}
   111  
   112  	switch x := lab.(type) {
   113  	case *ast.Ident:
   114  		return x.Name
   115  
   116  	case *ast.BasicLit:
   117  		if x.Kind == token.STRING {
   118  			s, err := literal.Unquote(x.Value)
   119  			if err == nil && ast.IsValidIdent(s) {
   120  				return s
   121  			}
   122  		}
   123  		return x.Value
   124  
   125  	case *ast.ListLit:
   126  		return "[]" // TODO: more detail
   127  
   128  	case *ast.Interpolation:
   129  		return "?"
   130  		// case *ast.ParenExpr:
   131  	}
   132  	return "<unknown>"
   133  }
   134  
   135  type forScope ast.ForClause
   136  
   137  func (l *forScope) labelString() string {
   138  	// TODO: include more info in square brackets.
   139  	return "for[]"
   140  }
   141  
   142  type letScope ast.LetClause
   143  
   144  func (l *letScope) labelString() string {
   145  	// TODO: include more info in square brackets.
   146  	return "let[]"
   147  }