diff options
Diffstat (limited to 'vendor/github.com/gobwas/glob/syntax/ast/parser.go')
-rw-r--r-- | vendor/github.com/gobwas/glob/syntax/ast/parser.go | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/vendor/github.com/gobwas/glob/syntax/ast/parser.go b/vendor/github.com/gobwas/glob/syntax/ast/parser.go new file mode 100644 index 000000000..429b40943 --- /dev/null +++ b/vendor/github.com/gobwas/glob/syntax/ast/parser.go @@ -0,0 +1,157 @@ +package ast + +import ( + "errors" + "fmt" + "github.com/gobwas/glob/syntax/lexer" + "unicode/utf8" +) + +type Lexer interface { + Next() lexer.Token +} + +type parseFn func(*Node, Lexer) (parseFn, *Node, error) + +func Parse(lexer Lexer) (*Node, error) { + var parser parseFn + + root := NewNode(KindPattern, nil) + + var ( + tree *Node + err error + ) + for parser, tree = parserMain, root; parser != nil; { + parser, tree, err = parser(tree, lexer) + if err != nil { + return nil, err + } + } + + return root, nil +} + +func parserMain(tree *Node, lex Lexer) (parseFn, *Node, error) { + for { + token := lex.Next() + switch token.Type { + case lexer.EOF: + return nil, tree, nil + + case lexer.Error: + return nil, tree, errors.New(token.Raw) + + case lexer.Text: + Insert(tree, NewNode(KindText, Text{token.Raw})) + return parserMain, tree, nil + + case lexer.Any: + Insert(tree, NewNode(KindAny, nil)) + return parserMain, tree, nil + + case lexer.Super: + Insert(tree, NewNode(KindSuper, nil)) + return parserMain, tree, nil + + case lexer.Single: + Insert(tree, NewNode(KindSingle, nil)) + return parserMain, tree, nil + + case lexer.RangeOpen: + return parserRange, tree, nil + + case lexer.TermsOpen: + a := NewNode(KindAnyOf, nil) + Insert(tree, a) + + p := NewNode(KindPattern, nil) + Insert(a, p) + + return parserMain, p, nil + + case lexer.Separator: + p := NewNode(KindPattern, nil) + Insert(tree.Parent, p) + + return parserMain, p, nil + + case lexer.TermsClose: + return parserMain, tree.Parent.Parent, nil + + default: + return nil, tree, fmt.Errorf("unexpected token: %s", token) + } + } + return nil, tree, fmt.Errorf("unknown error") +} + +func parserRange(tree *Node, lex Lexer) (parseFn, *Node, error) { + var ( + not bool + lo rune + hi rune + chars string + ) + for { + token := lex.Next() + switch token.Type { + case lexer.EOF: + return nil, tree, errors.New("unexpected end") + + case lexer.Error: + return nil, tree, errors.New(token.Raw) + + case lexer.Not: + not = true + + case lexer.RangeLo: + r, w := utf8.DecodeRuneInString(token.Raw) + if len(token.Raw) > w { + return nil, tree, fmt.Errorf("unexpected length of lo character") + } + lo = r + + case lexer.RangeBetween: + // + + case lexer.RangeHi: + r, w := utf8.DecodeRuneInString(token.Raw) + if len(token.Raw) > w { + return nil, tree, fmt.Errorf("unexpected length of lo character") + } + + hi = r + + if hi < lo { + return nil, tree, fmt.Errorf("hi character '%s' should be greater than lo '%s'", string(hi), string(lo)) + } + + case lexer.Text: + chars = token.Raw + + case lexer.RangeClose: + isRange := lo != 0 && hi != 0 + isChars := chars != "" + + if isChars == isRange { + return nil, tree, fmt.Errorf("could not parse range") + } + + if isRange { + Insert(tree, NewNode(KindRange, Range{ + Lo: lo, + Hi: hi, + Not: not, + })) + } else { + Insert(tree, NewNode(KindList, List{ + Chars: chars, + Not: not, + })) + } + + return parserMain, tree, nil + } + } +} |