Method Parse

parser/parser.go:98–133

Parse parses the expression represented by source and returns the result.

(source common.Source)

// Parse parses the expression represented by source and returns the result.
func (p *Parser) Parse(source common.Source) (*ast.AST, *common.Errors) {
	errs := common.NewErrors(source)
	accu := AccumulatorName
	if p.enableHiddenAccumulatorName {
		accu = HiddenAccumulatorName
	}
	fac := ast.NewExprFactoryWithAccumulator(accu)
	impl := parser{
		errors:                           &parseErrors{errs},
		exprFactory:                      fac,
		helper:                           newParserHelper(source, fac),
		macros:                           p.macros,
		maxRecursionDepth:                p.maxRecursionDepth,
		maxExpressionNodeCount:           p.maxExpressionNodeCount,
		errorReportingLimit:              p.errorReportingLimit,
		errorRecoveryLimit:               p.errorRecoveryLimit,
		errorRecoveryLookaheadTokenLimit: p.errorRecoveryTokenLookaheadLimit,
		populateMacroCalls:               p.populateMacroCalls,
		enableOptionalSyntax:             p.enableOptionalSyntax,
		enableVariadicOperatorASTs:       p.enableVariadicOperatorASTs,
		enableIdentEscapeSyntax:          p.enableIdentEscapeSyntax,
	}
	buf, ok := source.(runes.Buffer)
	if !ok {
		buf = runes.NewBuffer(source.Content())
	}
	var out ast.Expr
	if buf.Len() > p.expressionSizeCodePointLimit {
		out = impl.reportError(common.NoLocation,
			"expression code point size exceeds limit: size: %d, limit %d",
			buf.Len(), p.expressionSizeCodePointLimit)
	} else {
		out = impl.parse(buf, source.Description())
	}
	return ast.NewAST(out, impl.helper.getSourceInfo()), errs
}

// reservedIds are not legal to use as variables.  We exclude them post-parse, as they *are* valid
// field names for protos, and it would complicate the grammar to distinguish the cases.