github.com/hasnat/dolt/go@v0.0.0-20210628190320-9eb5d843fbb7/store/types/string.go (about)

     1  // Copyright 2019 Dolthub, Inc.
     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  // This file incorporates work covered by the following copyright and
    16  // permission notice:
    17  //
    18  // Copyright 2016 Attic Labs, Inc. All rights reserved.
    19  // Licensed under the Apache License, version 2.0:
    20  // http://www.apache.org/licenses/LICENSE-2.0
    21  
    22  package types
    23  
    24  import (
    25  	"context"
    26  	"errors"
    27  	"fmt"
    28  	"strconv"
    29  
    30  	"github.com/dolthub/dolt/go/store/hash"
    31  )
    32  
    33  // String is a Noms Value wrapper around the primitive string type.
    34  type String string
    35  
    36  // Value interface
    37  func (s String) Value(ctx context.Context) (Value, error) {
    38  	return s, nil
    39  }
    40  
    41  func (s String) Equals(other Value) bool {
    42  	return s == other
    43  }
    44  
    45  func (s String) Less(nbf *NomsBinFormat, other LesserValuable) (bool, error) {
    46  	if s2, ok := other.(String); ok {
    47  		return s < s2, nil
    48  	}
    49  	return StringKind < other.Kind(), nil
    50  }
    51  
    52  func (s String) Hash(nbf *NomsBinFormat) (hash.Hash, error) {
    53  	return getHash(s, nbf)
    54  }
    55  
    56  func (s String) isPrimitive() bool {
    57  	return true
    58  }
    59  
    60  func (s String) WalkValues(ctx context.Context, cb ValueCallback) error {
    61  	return nil
    62  }
    63  
    64  func (s String) WalkRefs(nbf *NomsBinFormat, cb RefCallback) error {
    65  	return nil
    66  }
    67  
    68  func (s String) typeOf() (*Type, error) {
    69  	return PrimitiveTypeMap[StringKind], nil
    70  }
    71  
    72  func (s String) Kind() NomsKind {
    73  	return StringKind
    74  }
    75  
    76  func (s String) valueReadWriter() ValueReadWriter {
    77  	return nil
    78  }
    79  
    80  func (s String) writeTo(w nomsWriter, nbf *NomsBinFormat) error {
    81  	err := StringKind.writeTo(w, nbf)
    82  
    83  	if err != nil {
    84  		return err
    85  	}
    86  
    87  	w.writeString(string(s))
    88  
    89  	return nil
    90  }
    91  
    92  func (s String) readFrom(nbf *NomsBinFormat, b *binaryNomsReader) (Value, error) {
    93  	return String(b.ReadString()), nil
    94  }
    95  
    96  func (s String) skip(nbf *NomsBinFormat, b *binaryNomsReader) {
    97  	b.skipString()
    98  }
    99  
   100  func parseNumber(s String) (isNegative bool, decPos int, err error) {
   101  	decPos = -1
   102  	for i, c := range s {
   103  		if i == 0 && c == '-' {
   104  			isNegative = true
   105  		} else if c == '.' {
   106  			if decPos != -1 {
   107  				return false, -1, errors.New("not a valid number.  multiple decimal points found.")
   108  			}
   109  
   110  			decPos = i
   111  		} else if c > '9' || c < '0' {
   112  			return false, -1, fmt.Errorf("for the string '%s' found invalid character '%s' at pos %d", s, string(c), i)
   113  		}
   114  	}
   115  
   116  	return isNegative, decPos, nil
   117  }
   118  
   119  func (s String) HumanReadableString() string {
   120  	return strconv.Quote(string(s))
   121  }