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| 1 // Copyright 2011 The Go Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style |
| 3 // license that can be found in the LICENSE file. |
| 4 |
| 5 package main |
| 6 |
| 7 import ( |
| 8 "go/ast" |
| 9 "go/token" |
| 10 ) |
| 11 |
| 12 var stringssplitFix = fix{ |
| 13 "stringssplit", |
| 14 stringssplit, |
| 15 `Restore strings.Split to its original meaning and add strings.SplitN. B
ytes too. |
| 16 |
| 17 http://codereview.appspot.com/4661051 |
| 18 `, |
| 19 } |
| 20 |
| 21 func init() { |
| 22 register(stringssplitFix) |
| 23 } |
| 24 |
| 25 func stringssplit(f *ast.File) bool { |
| 26 if !imports(f, "bytes") && !imports(f, "strings") { |
| 27 return false |
| 28 } |
| 29 |
| 30 fixed := false |
| 31 walk(f, func(n interface{}) { |
| 32 call, ok := n.(*ast.CallExpr) |
| 33 // func Split(s, sep string, n int) []string |
| 34 // func SplitAfter(s, sep string, n int) []string |
| 35 if !ok || len(call.Args) != 3 { |
| 36 return |
| 37 } |
| 38 // Is this our function? |
| 39 switch { |
| 40 case isPkgDot(call.Fun, "bytes", "Split"): |
| 41 case isPkgDot(call.Fun, "bytes", "SplitAfter"): |
| 42 case isPkgDot(call.Fun, "strings", "Split"): |
| 43 case isPkgDot(call.Fun, "strings", "SplitAfter"): |
| 44 default: |
| 45 return |
| 46 } |
| 47 |
| 48 sel := call.Fun.(*ast.SelectorExpr) |
| 49 args := call.Args |
| 50 fixed = true // We're committed. |
| 51 |
| 52 // Is the last argument -1? If so, drop the arg. |
| 53 // (Actually we just look for a negative integer literal.) |
| 54 // Otherwise, Split->SplitN and keep the arg. |
| 55 final := args[2] |
| 56 if unary, ok := final.(*ast.UnaryExpr); ok && unary.Op == token.
SUB { |
| 57 if lit, ok := unary.X.(*ast.BasicLit); ok { |
| 58 // Is it an integer? If so, it's a negative inte
ger and that's what we're after. |
| 59 if lit.Kind == token.INT { |
| 60 // drop the last arg. |
| 61 call.Args = args[0:2] |
| 62 return |
| 63 } |
| 64 } |
| 65 } |
| 66 |
| 67 // If not, rename and keep the argument list. |
| 68 sel.Sel.Name += "N" |
| 69 }) |
| 70 return fixed |
| 71 } |
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