Method parse

postgres/parser/parser/parse.go:203–237

parse parses a statement from the given scanned tokens.

(
	depth int, sql string, tokens []sqlSymType, nakedIntType *types.T,
)

// parse parses a statement from the given scanned tokens.
func (p *Parser) parse(
	depth int, sql string, tokens []sqlSymType, nakedIntType *types.T,
) (Statement, error) {
	p.lexer.init(sql, tokens, nakedIntType)
	defer p.lexer.cleanup()
	if p.parserImpl.Parse(&p.lexer) != 0 {
		if p.lexer.lastError == nil {
			// This should never happen -- there should be an error object
			// every time Parse() returns nonzero. We're just playing safe
			// here.
			p.lexer.Error("syntax error")
		}
		err := p.lexer.lastError

		// Compatibility with 19.1 telemetry: prefix the telemetry keys
		// with the "syntax." prefix.
		// TODO(knz): move the auto-prefixing of feature names to a
		// higher level in the call stack.
		tkeys := errors.GetTelemetryKeys(err)
		if len(tkeys) > 0 {
			for i := range tkeys {
				tkeys[i] = "syntax." + tkeys[i]
			}
			err = errors.WithTelemetry(err, tkeys...)
		}

		return Statement{}, err
	}
	return Statement{
		AST:             p.lexer.stmt,
		SQL:             sql,
		NumPlaceholders: p.lexer.numPlaceholders,
		NumAnnotations:  p.lexer.numAnnotations,
	}, nil
}

// unaryNegation constructs an AST node for a negation. This attempts
// to preserve constant NumVals and embed the negative sign inside