mirror of
https://codeberg.org/forgejo/forgejo
synced 2024-12-05 02:54:46 +01:00
275 lines
8.2 KiB
Go
275 lines
8.2 KiB
Go
|
package syntax
|
||
|
|
||
|
import (
|
||
|
"bytes"
|
||
|
"fmt"
|
||
|
"math"
|
||
|
)
|
||
|
|
||
|
// similar to prog.go in the go regex package...also with comment 'may not belong in this package'
|
||
|
|
||
|
// File provides operator constants for use by the Builder and the Machine.
|
||
|
|
||
|
// Implementation notes:
|
||
|
//
|
||
|
// Regexps are built into RegexCodes, which contain an operation array,
|
||
|
// a string table, and some constants.
|
||
|
//
|
||
|
// Each operation is one of the codes below, followed by the integer
|
||
|
// operands specified for each op.
|
||
|
//
|
||
|
// Strings and sets are indices into a string table.
|
||
|
|
||
|
type InstOp int
|
||
|
|
||
|
const (
|
||
|
// lef/back operands description
|
||
|
|
||
|
Onerep InstOp = 0 // lef,back char,min,max a {n}
|
||
|
Notonerep = 1 // lef,back char,min,max .{n}
|
||
|
Setrep = 2 // lef,back set,min,max [\d]{n}
|
||
|
|
||
|
Oneloop = 3 // lef,back char,min,max a {,n}
|
||
|
Notoneloop = 4 // lef,back char,min,max .{,n}
|
||
|
Setloop = 5 // lef,back set,min,max [\d]{,n}
|
||
|
|
||
|
Onelazy = 6 // lef,back char,min,max a {,n}?
|
||
|
Notonelazy = 7 // lef,back char,min,max .{,n}?
|
||
|
Setlazy = 8 // lef,back set,min,max [\d]{,n}?
|
||
|
|
||
|
One = 9 // lef char a
|
||
|
Notone = 10 // lef char [^a]
|
||
|
Set = 11 // lef set [a-z\s] \w \s \d
|
||
|
|
||
|
Multi = 12 // lef string abcd
|
||
|
Ref = 13 // lef group \#
|
||
|
|
||
|
Bol = 14 // ^
|
||
|
Eol = 15 // $
|
||
|
Boundary = 16 // \b
|
||
|
Nonboundary = 17 // \B
|
||
|
Beginning = 18 // \A
|
||
|
Start = 19 // \G
|
||
|
EndZ = 20 // \Z
|
||
|
End = 21 // \Z
|
||
|
|
||
|
Nothing = 22 // Reject!
|
||
|
|
||
|
// Primitive control structures
|
||
|
|
||
|
Lazybranch = 23 // back jump straight first
|
||
|
Branchmark = 24 // back jump branch first for loop
|
||
|
Lazybranchmark = 25 // back jump straight first for loop
|
||
|
Nullcount = 26 // back val set counter, null mark
|
||
|
Setcount = 27 // back val set counter, make mark
|
||
|
Branchcount = 28 // back jump,limit branch++ if zero<=c<limit
|
||
|
Lazybranchcount = 29 // back jump,limit same, but straight first
|
||
|
Nullmark = 30 // back save position
|
||
|
Setmark = 31 // back save position
|
||
|
Capturemark = 32 // back group define group
|
||
|
Getmark = 33 // back recall position
|
||
|
Setjump = 34 // back save backtrack state
|
||
|
Backjump = 35 // zap back to saved state
|
||
|
Forejump = 36 // zap backtracking state
|
||
|
Testref = 37 // backtrack if ref undefined
|
||
|
Goto = 38 // jump just go
|
||
|
|
||
|
Prune = 39 // prune it baby
|
||
|
Stop = 40 // done!
|
||
|
|
||
|
ECMABoundary = 41 // \b
|
||
|
NonECMABoundary = 42 // \B
|
||
|
|
||
|
// Modifiers for alternate modes
|
||
|
|
||
|
Mask = 63 // Mask to get unmodified ordinary operator
|
||
|
Rtl = 64 // bit to indicate that we're reverse scanning.
|
||
|
Back = 128 // bit to indicate that we're backtracking.
|
||
|
Back2 = 256 // bit to indicate that we're backtracking on a second branch.
|
||
|
Ci = 512 // bit to indicate that we're case-insensitive.
|
||
|
)
|
||
|
|
||
|
type Code struct {
|
||
|
Codes []int // the code
|
||
|
Strings [][]rune // string table
|
||
|
Sets []*CharSet //character set table
|
||
|
TrackCount int // how many instructions use backtracking
|
||
|
Caps map[int]int // mapping of user group numbers -> impl group slots
|
||
|
Capsize int // number of impl group slots
|
||
|
FcPrefix *Prefix // the set of candidate first characters (may be null)
|
||
|
BmPrefix *BmPrefix // the fixed prefix string as a Boyer-Moore machine (may be null)
|
||
|
Anchors AnchorLoc // the set of zero-length start anchors (RegexFCD.Bol, etc)
|
||
|
RightToLeft bool // true if right to left
|
||
|
}
|
||
|
|
||
|
func opcodeBacktracks(op InstOp) bool {
|
||
|
op &= Mask
|
||
|
|
||
|
switch op {
|
||
|
case Oneloop, Notoneloop, Setloop, Onelazy, Notonelazy, Setlazy, Lazybranch, Branchmark, Lazybranchmark,
|
||
|
Nullcount, Setcount, Branchcount, Lazybranchcount, Setmark, Capturemark, Getmark, Setjump, Backjump,
|
||
|
Forejump, Goto:
|
||
|
return true
|
||
|
|
||
|
default:
|
||
|
return false
|
||
|
}
|
||
|
}
|
||
|
|
||
|
func opcodeSize(op InstOp) int {
|
||
|
op &= Mask
|
||
|
|
||
|
switch op {
|
||
|
case Nothing, Bol, Eol, Boundary, Nonboundary, ECMABoundary, NonECMABoundary, Beginning, Start, EndZ,
|
||
|
End, Nullmark, Setmark, Getmark, Setjump, Backjump, Forejump, Stop:
|
||
|
return 1
|
||
|
|
||
|
case One, Notone, Multi, Ref, Testref, Goto, Nullcount, Setcount, Lazybranch, Branchmark, Lazybranchmark,
|
||
|
Prune, Set:
|
||
|
return 2
|
||
|
|
||
|
case Capturemark, Branchcount, Lazybranchcount, Onerep, Notonerep, Oneloop, Notoneloop, Onelazy, Notonelazy,
|
||
|
Setlazy, Setrep, Setloop:
|
||
|
return 3
|
||
|
|
||
|
default:
|
||
|
panic(fmt.Errorf("Unexpected op code: %v", op))
|
||
|
}
|
||
|
}
|
||
|
|
||
|
var codeStr = []string{
|
||
|
"Onerep", "Notonerep", "Setrep",
|
||
|
"Oneloop", "Notoneloop", "Setloop",
|
||
|
"Onelazy", "Notonelazy", "Setlazy",
|
||
|
"One", "Notone", "Set",
|
||
|
"Multi", "Ref",
|
||
|
"Bol", "Eol", "Boundary", "Nonboundary", "Beginning", "Start", "EndZ", "End",
|
||
|
"Nothing",
|
||
|
"Lazybranch", "Branchmark", "Lazybranchmark",
|
||
|
"Nullcount", "Setcount", "Branchcount", "Lazybranchcount",
|
||
|
"Nullmark", "Setmark", "Capturemark", "Getmark",
|
||
|
"Setjump", "Backjump", "Forejump", "Testref", "Goto",
|
||
|
"Prune", "Stop",
|
||
|
"ECMABoundary", "NonECMABoundary",
|
||
|
}
|
||
|
|
||
|
func operatorDescription(op InstOp) string {
|
||
|
desc := codeStr[op&Mask]
|
||
|
if (op & Ci) != 0 {
|
||
|
desc += "-Ci"
|
||
|
}
|
||
|
if (op & Rtl) != 0 {
|
||
|
desc += "-Rtl"
|
||
|
}
|
||
|
if (op & Back) != 0 {
|
||
|
desc += "-Back"
|
||
|
}
|
||
|
if (op & Back2) != 0 {
|
||
|
desc += "-Back2"
|
||
|
}
|
||
|
|
||
|
return desc
|
||
|
}
|
||
|
|
||
|
// OpcodeDescription is a humman readable string of the specific offset
|
||
|
func (c *Code) OpcodeDescription(offset int) string {
|
||
|
buf := &bytes.Buffer{}
|
||
|
|
||
|
op := InstOp(c.Codes[offset])
|
||
|
fmt.Fprintf(buf, "%06d ", offset)
|
||
|
|
||
|
if opcodeBacktracks(op & Mask) {
|
||
|
buf.WriteString("*")
|
||
|
} else {
|
||
|
buf.WriteString(" ")
|
||
|
}
|
||
|
buf.WriteString(operatorDescription(op))
|
||
|
buf.WriteString("(")
|
||
|
op &= Mask
|
||
|
|
||
|
switch op {
|
||
|
case One, Notone, Onerep, Notonerep, Oneloop, Notoneloop, Onelazy, Notonelazy:
|
||
|
buf.WriteString("Ch = ")
|
||
|
buf.WriteString(CharDescription(rune(c.Codes[offset+1])))
|
||
|
|
||
|
case Set, Setrep, Setloop, Setlazy:
|
||
|
buf.WriteString("Set = ")
|
||
|
buf.WriteString(c.Sets[c.Codes[offset+1]].String())
|
||
|
|
||
|
case Multi:
|
||
|
fmt.Fprintf(buf, "String = %s", string(c.Strings[c.Codes[offset+1]]))
|
||
|
|
||
|
case Ref, Testref:
|
||
|
fmt.Fprintf(buf, "Index = %d", c.Codes[offset+1])
|
||
|
|
||
|
case Capturemark:
|
||
|
fmt.Fprintf(buf, "Index = %d", c.Codes[offset+1])
|
||
|
if c.Codes[offset+2] != -1 {
|
||
|
fmt.Fprintf(buf, ", Unindex = %d", c.Codes[offset+2])
|
||
|
}
|
||
|
|
||
|
case Nullcount, Setcount:
|
||
|
fmt.Fprintf(buf, "Value = %d", c.Codes[offset+1])
|
||
|
|
||
|
case Goto, Lazybranch, Branchmark, Lazybranchmark, Branchcount, Lazybranchcount:
|
||
|
fmt.Fprintf(buf, "Addr = %d", c.Codes[offset+1])
|
||
|
}
|
||
|
|
||
|
switch op {
|
||
|
case Onerep, Notonerep, Oneloop, Notoneloop, Onelazy, Notonelazy, Setrep, Setloop, Setlazy:
|
||
|
buf.WriteString(", Rep = ")
|
||
|
if c.Codes[offset+2] == math.MaxInt32 {
|
||
|
buf.WriteString("inf")
|
||
|
} else {
|
||
|
fmt.Fprintf(buf, "%d", c.Codes[offset+2])
|
||
|
}
|
||
|
|
||
|
case Branchcount, Lazybranchcount:
|
||
|
buf.WriteString(", Limit = ")
|
||
|
if c.Codes[offset+2] == math.MaxInt32 {
|
||
|
buf.WriteString("inf")
|
||
|
} else {
|
||
|
fmt.Fprintf(buf, "%d", c.Codes[offset+2])
|
||
|
}
|
||
|
|
||
|
}
|
||
|
|
||
|
buf.WriteString(")")
|
||
|
|
||
|
return buf.String()
|
||
|
}
|
||
|
|
||
|
func (c *Code) Dump() string {
|
||
|
buf := &bytes.Buffer{}
|
||
|
|
||
|
if c.RightToLeft {
|
||
|
fmt.Fprintln(buf, "Direction: right-to-left")
|
||
|
} else {
|
||
|
fmt.Fprintln(buf, "Direction: left-to-right")
|
||
|
}
|
||
|
if c.FcPrefix == nil {
|
||
|
fmt.Fprintln(buf, "Firstchars: n/a")
|
||
|
} else {
|
||
|
fmt.Fprintf(buf, "Firstchars: %v\n", c.FcPrefix.PrefixSet.String())
|
||
|
}
|
||
|
|
||
|
if c.BmPrefix == nil {
|
||
|
fmt.Fprintln(buf, "Prefix: n/a")
|
||
|
} else {
|
||
|
fmt.Fprintf(buf, "Prefix: %v\n", Escape(c.BmPrefix.String()))
|
||
|
}
|
||
|
|
||
|
fmt.Fprintf(buf, "Anchors: %v\n", c.Anchors)
|
||
|
fmt.Fprintln(buf)
|
||
|
|
||
|
if c.BmPrefix != nil {
|
||
|
fmt.Fprintln(buf, "BoyerMoore:")
|
||
|
fmt.Fprintln(buf, c.BmPrefix.Dump(" "))
|
||
|
}
|
||
|
for i := 0; i < len(c.Codes); i += opcodeSize(InstOp(c.Codes[i])) {
|
||
|
fmt.Fprintln(buf, c.OpcodeDescription(i))
|
||
|
}
|
||
|
|
||
|
return buf.String()
|
||
|
}
|