github.com/cheng762/platon-go@v1.8.17-0.20190529111256-7deff2d7be26/internal/jsre/completion.go (about)

     1  // Copyright 2016 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package jsre
    18  
    19  import (
    20  	"sort"
    21  	"strings"
    22  
    23  	"github.com/robertkrimen/otto"
    24  )
    25  
    26  // CompleteKeywords returns potential continuations for the given line. Since line is
    27  // evaluated, callers need to make sure that evaluating line does not have side effects.
    28  func (jsre *JSRE) CompleteKeywords(line string) []string {
    29  	var results []string
    30  	jsre.Do(func(vm *otto.Otto) {
    31  		results = getCompletions(vm, line)
    32  	})
    33  	return results
    34  }
    35  
    36  func getCompletions(vm *otto.Otto, line string) (results []string) {
    37  	parts := strings.Split(line, ".")
    38  	objRef := "this"
    39  	prefix := line
    40  	if len(parts) > 1 {
    41  		objRef = strings.Join(parts[0:len(parts)-1], ".")
    42  		prefix = parts[len(parts)-1]
    43  	}
    44  
    45  	obj, _ := vm.Object(objRef)
    46  	if obj == nil {
    47  		return nil
    48  	}
    49  	iterOwnAndConstructorKeys(vm, obj, func(k string) {
    50  		if strings.HasPrefix(k, prefix) {
    51  			if objRef == "this" {
    52  				results = append(results, k)
    53  			} else {
    54  				results = append(results, strings.Join(parts[:len(parts)-1], ".")+"."+k)
    55  			}
    56  		}
    57  	})
    58  
    59  	// Append opening parenthesis (for functions) or dot (for objects)
    60  	// if the line itself is the only completion.
    61  	if len(results) == 1 && results[0] == line {
    62  		obj, _ := vm.Object(line)
    63  		if obj != nil {
    64  			if obj.Class() == "Function" {
    65  				results[0] += "("
    66  			} else {
    67  				results[0] += "."
    68  			}
    69  		}
    70  	}
    71  
    72  	sort.Strings(results)
    73  	return results
    74  }