95 lines
1.9 KiB
Go
95 lines
1.9 KiB
Go
package fastjson
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import (
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"errors"
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)
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// Scanner scans a series of JSON values. Values may be delimited by whitespace.
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//
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// Scanner may parse JSON lines ( http://jsonlines.org/ ).
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//
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// Scanner may be re-used for subsequent parsing.
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//
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// Scanner cannot be used from concurrent goroutines.
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//
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// Use Parser for parsing only a single JSON value.
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type Scanner struct {
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// b contains a working copy of json value passed to Init.
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b []byte
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// s points to the next JSON value to parse.
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s string
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// err contains the last error.
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err error
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// v contains the last parsed JSON value.
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v *Value
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// c is used for caching JSON values.
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c cache
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}
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// Init initializes sc with the given s.
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//
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// s may contain multiple JSON values, which may be delimited by whitespace.
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func (sc *Scanner) Init(s string) {
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sc.b = append(sc.b[:0], s...)
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sc.s = b2s(sc.b)
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sc.err = nil
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sc.v = nil
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}
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// InitBytes initializes sc with the given b.
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//
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// b may contain multiple JSON values, which may be delimited by whitespace.
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func (sc *Scanner) InitBytes(b []byte) {
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sc.Init(b2s(b))
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}
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// Next parses the next JSON value from s passed to Init.
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//
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// Returns true on success. The parsed value is available via Value call.
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//
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// Returns false either on error or on the end of s.
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// Call Error in order to determine the cause of the returned false.
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func (sc *Scanner) Next() bool {
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if sc.err != nil {
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return false
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}
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sc.s = skipWS(sc.s)
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if len(sc.s) == 0 {
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sc.err = errEOF
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return false
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}
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sc.c.reset()
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v, tail, err := parseValue(sc.s, &sc.c, 0)
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if err != nil {
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sc.err = err
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return false
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}
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sc.s = tail
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sc.v = v
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return true
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}
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// Error returns the last error.
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func (sc *Scanner) Error() error {
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if sc.err == errEOF {
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return nil
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}
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return sc.err
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}
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// Value returns the last parsed value.
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//
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// The value is valid until the Next call.
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func (sc *Scanner) Value() *Value {
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return sc.v
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}
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var errEOF = errors.New("end of s")
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