arf/parser/objt.go

package parser

import "git.tebibyte.media/arf/arf/types"
import "git.tebibyte.media/arf/arf/lexer"
import "git.tebibyte.media/arf/arf/infoerr"

// parseObjtSection parses an object type definition. This allows for structured
// types to be defined, and for member variables to be added and overridden.
func (parser *ParsingOperation) parseObjtSection () (
	section *ObjtSection,
	err     error,
) {
	err = parser.expect(lexer.TokenKindName)
	if err != nil { return }
	
	section = &ObjtSection { }
	section.location = parser.token.Location()

	// get permission
	err = parser.nextToken(lexer.TokenKindPermission)
	if err != nil { return }
	section.permission = parser.token.Value().(types.Permission)

	// get name
	err = parser.nextToken(lexer.TokenKindName)
	if err != nil { return }
	section.name = parser.token.Value().(string)

	// parse inherited type
	err = parser.nextToken(lexer.TokenKindColon)
	if err != nil { return }
	err = parser.nextToken()
	if err != nil { return }
	section.inherits, err = parser.parseIdentifier()
	if err != nil { return }
	err = parser.expect(lexer.TokenKindNewline)
	if err != nil { return }
	err = parser.nextToken()
	if err != nil { return }

	// parse members
	err = parser.parseObjtMembers(section)
	if err != nil { return }
	
	if len(section.members) == 0 {
		infoerr.NewError (
			section.location,
			"defining an object with no members",
			infoerr.ErrorKindWarn).Print()
	}
	return
}

// parseObjtMembers parses a list of members for an object section. Indentation
// level is assumed.
func (parser *ParsingOperation) parseObjtMembers (
	into *ObjtSection,
) (
	err     error,
) {
	for {
		// if we've left the block, stop parsing
		if !parser.token.Is(lexer.TokenKindIndent) { return }
		if parser.token.Value().(int) != 1         { return }
		
		// add member to object section
		var member ObjtMember
		member, err = parser.parseObjtMember()
		into.members = append(into.members, member)
		if err != nil { return }
	}
}

// parseObjtMember parses a single member of an object section. Indentation
// level is assumed.
func (parser *ParsingOperation) parseObjtMember () (
	member ObjtMember,
	err    error,
) {
	// get permission
	err = parser.nextToken(lexer.TokenKindPermission)
	if err != nil { return }
	member.permission = parser.token.Value().(types.Permission)

	// get name
	err = parser.nextToken(lexer.TokenKindName)
	if err != nil { return }
	member.name = parser.token.Value().(string)

	// get type
	err = parser.nextToken(lexer.TokenKindColon)
	if err != nil { return }
	err = parser.nextToken()
	if err != nil { return }
	member.what, err = parser.parseType()
	if err != nil { return }

	// if there is a bit width, get it
	if parser.token.Is(lexer.TokenKindBinaryAnd) {
		err = parser.nextToken(lexer.TokenKindUInt)
		if err != nil { return }
		member.bitWidth = parser.token.Value().(uint64)
		err = parser.nextToken()
		if err != nil { return }
	}
	
	// parse default value
	if parser.token.Is(lexer.TokenKindNewline) {
		err = parser.nextToken()
		if err != nil { return }

		member.defaultValue,
		err = parser.parseInitializationValues(1)
		if err != nil { return }
	} else {
		member.defaultValue, err = parser.parseArgument()
		if err != nil { return }

		err = parser.expect(lexer.TokenKindNewline)
		if err != nil { return }
		err = parser.nextToken()
		if err != nil { return }
	}

	return 
}