mirror of
https://github.com/superseriousbusiness/gotosocial
synced 2024-12-08 06:32:22 +01:00
a5f28fe0c9
Bumps [github.com/gin-contrib/gzip](https://github.com/gin-contrib/gzip) from 1.0.0 to 1.0.1. - [Release notes](https://github.com/gin-contrib/gzip/releases) - [Changelog](https://github.com/gin-contrib/gzip/blob/master/.goreleaser.yaml) - [Commits](https://github.com/gin-contrib/gzip/compare/v1.0.0...v1.0.1) --- updated-dependencies: - dependency-name: github.com/gin-contrib/gzip dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
330 lines
7.7 KiB
Go
330 lines
7.7 KiB
Go
//
|
|
// Copyright 2024 CloudWeGo Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
//
|
|
|
|
package expr
|
|
|
|
import (
|
|
`strconv`
|
|
`unicode`
|
|
`unsafe`
|
|
)
|
|
|
|
type _TokenKind uint8
|
|
|
|
const (
|
|
_T_end _TokenKind = iota + 1
|
|
_T_int
|
|
_T_punc
|
|
_T_name
|
|
)
|
|
|
|
const (
|
|
_OP2 = 0x80
|
|
_POW = _OP2 | '*'
|
|
_SHL = _OP2 | '<'
|
|
_SHR = _OP2 | '>'
|
|
)
|
|
|
|
type _Slice struct {
|
|
p unsafe.Pointer
|
|
n int
|
|
c int
|
|
}
|
|
|
|
type _Token struct {
|
|
pos int
|
|
ptr *rune
|
|
u64 uint64
|
|
tag _TokenKind
|
|
}
|
|
|
|
func (self _Token) str() (v string) {
|
|
return string(self.rbuf())
|
|
}
|
|
|
|
func (self _Token) rbuf() (v []rune) {
|
|
(*_Slice)(unsafe.Pointer(&v)).c = int(self.u64)
|
|
(*_Slice)(unsafe.Pointer(&v)).n = int(self.u64)
|
|
(*_Slice)(unsafe.Pointer(&v)).p = unsafe.Pointer(self.ptr)
|
|
return
|
|
}
|
|
|
|
func tokenEnd(p int) _Token {
|
|
return _Token {
|
|
pos: p,
|
|
tag: _T_end,
|
|
}
|
|
}
|
|
|
|
func tokenInt(p int, v uint64) _Token {
|
|
return _Token {
|
|
pos: p,
|
|
u64: v,
|
|
tag: _T_int,
|
|
}
|
|
}
|
|
|
|
func tokenPunc(p int, v rune) _Token {
|
|
return _Token {
|
|
pos: p,
|
|
tag: _T_punc,
|
|
u64: uint64(v),
|
|
}
|
|
}
|
|
|
|
func tokenName(p int, v []rune) _Token {
|
|
return _Token {
|
|
pos: p,
|
|
ptr: &v[0],
|
|
tag: _T_name,
|
|
u64: uint64(len(v)),
|
|
}
|
|
}
|
|
|
|
// Repository represents a repository of Term's.
|
|
type Repository interface {
|
|
Get(name string) (Term, error)
|
|
}
|
|
|
|
// Parser parses an expression string to it's AST representation.
|
|
type Parser struct {
|
|
pos int
|
|
src []rune
|
|
}
|
|
|
|
var binaryOps = [...]func(*Expr, *Expr) *Expr {
|
|
'+' : (*Expr).Add,
|
|
'-' : (*Expr).Sub,
|
|
'*' : (*Expr).Mul,
|
|
'/' : (*Expr).Div,
|
|
'%' : (*Expr).Mod,
|
|
'&' : (*Expr).And,
|
|
'^' : (*Expr).Xor,
|
|
'|' : (*Expr).Or,
|
|
_SHL : (*Expr).Shl,
|
|
_SHR : (*Expr).Shr,
|
|
_POW : (*Expr).Pow,
|
|
}
|
|
|
|
var precedence = [...]map[int]bool {
|
|
{_SHL: true, _SHR: true},
|
|
{'|' : true},
|
|
{'^' : true},
|
|
{'&' : true},
|
|
{'+' : true, '-': true},
|
|
{'*' : true, '/': true, '%': true},
|
|
{_POW: true},
|
|
}
|
|
|
|
func (self *Parser) ch() rune {
|
|
return self.src[self.pos]
|
|
}
|
|
|
|
func (self *Parser) eof() bool {
|
|
return self.pos >= len(self.src)
|
|
}
|
|
|
|
func (self *Parser) rch() (v rune) {
|
|
v, self.pos = self.src[self.pos], self.pos + 1
|
|
return
|
|
}
|
|
|
|
func (self *Parser) hex(ss []rune) bool {
|
|
if len(ss) == 1 && ss[0] == '0' {
|
|
return unicode.ToLower(self.ch()) == 'x'
|
|
} else if len(ss) <= 1 || unicode.ToLower(ss[1]) != 'x' {
|
|
return unicode.IsDigit(self.ch())
|
|
} else {
|
|
return ishexdigit(self.ch())
|
|
}
|
|
}
|
|
|
|
func (self *Parser) int(p int, ss []rune) (_Token, error) {
|
|
var err error
|
|
var val uint64
|
|
|
|
/* find all the digits */
|
|
for !self.eof() && self.hex(ss) {
|
|
ss = append(ss, self.rch())
|
|
}
|
|
|
|
/* parse the value */
|
|
if val, err = strconv.ParseUint(string(ss), 0, 64); err != nil {
|
|
return _Token{}, err
|
|
} else {
|
|
return tokenInt(p, val), nil
|
|
}
|
|
}
|
|
|
|
func (self *Parser) name(p int, ss []rune) _Token {
|
|
for !self.eof() && isident(self.ch()) { ss = append(ss, self.rch()) }
|
|
return tokenName(p, ss)
|
|
}
|
|
|
|
func (self *Parser) read(p int, ch rune) (_Token, error) {
|
|
if isdigit(ch) {
|
|
return self.int(p, []rune { ch })
|
|
} else if isident0(ch) {
|
|
return self.name(p, []rune { ch }), nil
|
|
} else if isop2ch(ch) && !self.eof() && self.ch() == ch {
|
|
return tokenPunc(p, _OP2 | self.rch()), nil
|
|
} else if isop1ch(ch) {
|
|
return tokenPunc(p, ch), nil
|
|
} else {
|
|
return _Token{}, newSyntaxError(self.pos, "invalid character " + strconv.QuoteRuneToASCII(ch))
|
|
}
|
|
}
|
|
|
|
func (self *Parser) next() (_Token, error) {
|
|
for {
|
|
var p int
|
|
var c rune
|
|
|
|
/* check for EOF */
|
|
if self.eof() {
|
|
return tokenEnd(self.pos), nil
|
|
}
|
|
|
|
/* read the next char */
|
|
p = self.pos
|
|
c = self.rch()
|
|
|
|
/* parse the token if not a space */
|
|
if !unicode.IsSpace(c) {
|
|
return self.read(p, c)
|
|
}
|
|
}
|
|
}
|
|
|
|
func (self *Parser) grab(tk _Token, repo Repository) (*Expr, error) {
|
|
if repo == nil {
|
|
return nil, newSyntaxError(tk.pos, "unresolved symbol: " + tk.str())
|
|
} else if term, err := repo.Get(tk.str()); err != nil {
|
|
return nil, err
|
|
} else {
|
|
return Ref(term), nil
|
|
}
|
|
}
|
|
|
|
func (self *Parser) nest(nest int, repo Repository) (*Expr, error) {
|
|
var err error
|
|
var ret *Expr
|
|
var ntk _Token
|
|
|
|
/* evaluate the nested expression */
|
|
if ret, err = self.expr(0, nest + 1, repo); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
/* must follows with a ')' */
|
|
if ntk, err = self.next(); err != nil {
|
|
return nil, err
|
|
} else if ntk.tag != _T_punc || ntk.u64 != ')' {
|
|
return nil, newSyntaxError(ntk.pos, "')' expected")
|
|
} else {
|
|
return ret, nil
|
|
}
|
|
}
|
|
|
|
func (self *Parser) unit(nest int, repo Repository) (*Expr, error) {
|
|
if tk, err := self.next(); err != nil {
|
|
return nil, err
|
|
} else if tk.tag == _T_int {
|
|
return Int(int64(tk.u64)), nil
|
|
} else if tk.tag == _T_name {
|
|
return self.grab(tk, repo)
|
|
} else if tk.tag == _T_punc && tk.u64 == '(' {
|
|
return self.nest(nest, repo)
|
|
} else if tk.tag == _T_punc && tk.u64 == '+' {
|
|
return self.unit(nest, repo)
|
|
} else if tk.tag == _T_punc && tk.u64 == '-' {
|
|
return neg2(self.unit(nest, repo))
|
|
} else if tk.tag == _T_punc && tk.u64 == '~' {
|
|
return not2(self.unit(nest, repo))
|
|
} else {
|
|
return nil, newSyntaxError(tk.pos, "integer, unary operator or nested expression expected")
|
|
}
|
|
}
|
|
|
|
func (self *Parser) term(prec int, nest int, repo Repository) (*Expr, error) {
|
|
var err error
|
|
var val *Expr
|
|
|
|
/* parse the LHS operand */
|
|
if val, err = self.expr(prec + 1, nest, repo); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
/* parse all the operators of the same precedence */
|
|
for {
|
|
var op int
|
|
var rv *Expr
|
|
var tk _Token
|
|
|
|
/* peek the next token */
|
|
pp := self.pos
|
|
tk, err = self.next()
|
|
|
|
/* check for errors */
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
/* encountered EOF */
|
|
if tk.tag == _T_end {
|
|
return val, nil
|
|
}
|
|
|
|
/* must be an operator */
|
|
if tk.tag != _T_punc {
|
|
return nil, newSyntaxError(tk.pos, "operators expected")
|
|
}
|
|
|
|
/* check for the operator precedence */
|
|
if op = int(tk.u64); !precedence[prec][op] {
|
|
self.pos = pp
|
|
return val, nil
|
|
}
|
|
|
|
/* evaluate the RHS operand, and combine the value */
|
|
if rv, err = self.expr(prec + 1, nest, repo); err != nil {
|
|
return nil, err
|
|
} else {
|
|
val = binaryOps[op](val, rv)
|
|
}
|
|
}
|
|
}
|
|
|
|
func (self *Parser) expr(prec int, nest int, repo Repository) (*Expr, error) {
|
|
if prec >= len(precedence) {
|
|
return self.unit(nest, repo)
|
|
} else {
|
|
return self.term(prec, nest, repo)
|
|
}
|
|
}
|
|
|
|
// Parse parses the expression, and returns it's AST tree.
|
|
func (self *Parser) Parse(repo Repository) (*Expr, error) {
|
|
return self.expr(0, 0, repo)
|
|
}
|
|
|
|
// SetSource resets the expression parser and sets the expression source.
|
|
func (self *Parser) SetSource(src string) *Parser {
|
|
self.pos = 0
|
|
self.src = []rune(src)
|
|
return self
|
|
}
|