75 lines
1.1 KiB
Go
75 lines
1.1 KiB
Go
package goparsify
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import (
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"fmt"
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)
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type Error struct {
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pos int
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Expected string
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}
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func (e Error) Pos() int { return e.pos }
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func (e Error) Error() string { return fmt.Sprintf("offset %d: Expected %s", e.pos, e.Expected) }
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type WSFunc func(c byte) bool
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type State struct {
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Input string
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Pos int
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Error Error
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WSFunc WSFunc
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NoAutoWS bool
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}
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func (s *State) Advance(i int) {
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s.Pos += i
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}
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// AutoWS consumes all whitespace
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func (s *State) AutoWS() {
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if s.NoAutoWS {
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return
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}
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s.WS()
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}
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func (s *State) WS() {
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for s.Pos < len(s.Input) && s.WSFunc(s.Input[s.Pos]) {
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s.Pos++
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}
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}
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func (s *State) Get() string {
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if s.Pos > len(s.Input) {
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return ""
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}
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return s.Input[s.Pos:]
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}
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func (s *State) ErrorHere(expected string) {
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s.Error.pos = s.Pos
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s.Error.Expected = expected
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}
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func (s *State) ClearError() {
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s.Error.Expected = ""
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}
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func (s *State) Errored() bool {
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return s.Error.Expected != ""
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}
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func InputString(input string) *State {
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return &State{
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Input: input,
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WSFunc: func(b byte) bool {
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switch b {
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case '\t', '\n', '\v', '\f', '\r', ' ':
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return true
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}
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return false
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},
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}
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}
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