README
¶
edit
Edit is an implementation of the Acme/Sam command language
usage
ed, _ := text.Open(text.NewBuffer())
ed.Insert([]byte("Removing vowels isnt the best way to name things"), 0)
cmd, _ := edit.Compile(",x,[aeiou],d")
cmd.Run(ed)
fmt.Printf("%s\n", ed.Bytes())
// Rmvng vwls snt th bst wy t nm thngs
example
See example/example.go
reference
Rob Pike pioneered structural regular expressions in the 1980s. The original implementations can be found in his Sam and Acme text editors.
http://doc.cat-v.org/bell_labs/structural_regexps/
http://doc.cat-v.org/bell_labs/sam_lang_tutorial/
appendix
This implementation now runs 10-1000 times faster
Benchmark before coalescing (2017.09.17)
goos: windows
goarch: amd64
BenchmarkChange128KBto64KB-4 1 3531749200 ns/op
BenchmarkChange128KBto128KB-4 1 3784740700 ns/op
BenchmarkChange128KBto128KBNest4x2x1-4 1 3642752800 ns/op
BenchmarkChange128KBto128KBx16x4x1-4 1 3589181900 ns/op
After coalescing (current)
goos: windows
goarch: amd64
pkg: github.com/as/edit
BenchmarkChange128KBto64KB-4 2 530753100 ns/op
BenchmarkChange128KBto128KB-4 200 6529711 ns/op
BenchmarkChange128KBto128KBNest4x2x1-4 200 6450888 ns/op
BenchmarkChange128KBto128KBx16x4x1-4 200 6333687 ns/op
BenchmarkDelete128KB-4 200000 11720 ns/op
BenchmarkDelete128KBx64-4 20 93447760 ns/op
BenchmarkDelete128KBx8-4 20 68008640 ns/op
BenchmarkDelete128KBx1-4 5 263001000 ns/op
BenchmarkDelete256KBx1-4 2 519648200 ns/op
BenchmarkDelete512KBx1-4 1 1032597800 ns/op
Documentation
¶
Overview ¶
Package edit implements a compiler for Acme Edit command language. The compiled Command operates on types satisfying the text.Editor interface. See github.com/as/text for more.
Index ¶
- Variables
- func Commit(ed Editor, hist worm.Logger) (err error)
- type Address
- type Append
- type Byte
- type Change
- type Command
- type Compound
- type Delete
- type Dot
- type Editor
- type Emitted
- type File
- type Insert
- type Kind
- type Line
- type Options
- type Pipe
- type Print
- type ReadFile
- type Recorder
- type Regexp
- type ReplaceAmp
- type S
- type Sender
- type Trade
- type WriteFile
Constants ¶
This section is empty.
Variables ¶
var ( ErrNilFunc = errors.New("empty program") ErrNilEditor = errors.New("nil editor") )
Functions ¶
func Commit ¶ added in v0.6.10
Commit plays back the history onto ed, starting from the last event to the first in reverse order. This is useful only when hist contains a set of independent events applied as a transaction where shifts in the address offsets are not observed.
If the command is
a,abc, x,.,a,Q,
The result is:
abc -> aQbQcQ
The log should contain
i 1 Q i 2 Q (not i 3 Q) i 3 Q (not i 5 Q)
Commit will only reallocate ed's size once. If ed implements io.WriterAt, a write-through fast path is used to commit the transaction.
Types ¶
type Address ¶
type Address interface {
// Set computes and sets the address on the provided Editor
Set(f Editor)
// Back returns true if the address semantics should be executed in reverse
Back() bool
}
Address implements Set on the Editor. Possibly selecting some range of text (a dot).
type Byte ¶
type Byte struct {
Q int64
// contains filtered or unexported fields
}
Bytes is an address computed by a relative or absolute byte offset
type Command ¶
type Command struct {
Emit *Emitted
// contains filtered or unexported fields
}
func MustCompile ¶
func (*Command) Modified ¶
Modified returns true if the last call to c.Run() modified the contents of the editor
func (*Command) Next ¶
Next returns the next instruction for the compiled program. This effectively steps through x,..., and y,...,
func (*Command) RunTransaction ¶ added in v0.6.10
Run runs the compiled program on ed
type Compound ¶
type Compound struct {
// contains filtered or unexported fields
}
Compound combines two address values with an operator
type Line ¶
type Line struct {
Q int64
// contains filtered or unexported fields
}
Line is an address computed by a relative or absolute byte offset
type Recorder ¶ added in v0.6.11
type Recorder struct {
Editor
}
Recorder is an overlay over an Editor that prevents mutable changes from occuring.
type Regexp ¶
type Regexp struct {
// contains filtered or unexported fields
}
Regexp is an address computed by a regexp
type ReplaceAmp ¶
func (ReplaceAmp) Gen ¶
func (r ReplaceAmp) Gen(replace []byte) (b []byte)
Source Files
Directories