3 Commits

Author SHA1 Message Date
amery ee2e5c2001 build-sys: use local asciigoat.org/core [DO-NOT-MERGE]
Signed-off-by: Alejandro Mery <amery@jpi.io>
2023-08-31 00:19:16 +00:00
amery 330d885a60 parser: add initial Parser emitting non-whitespace tokens
Signed-off-by: Alejandro Mery <amery@jpi.io>
2023-08-31 00:18:36 +00:00
amery a15deb7e42 tools: add stringer support
Signed-off-by: Alejandro Mery <amery@jpi.io>
2023-08-30 23:01:22 +00:00
7 changed files with 114 additions and 162 deletions
+21 -28
View File
@@ -1,8 +1,6 @@
package parser
import (
"asciigoat.org/core/lexer"
)
import "asciigoat.org/core/lexer"
// Run parses the source
func (p *Parser) Run() error {
@@ -17,46 +15,24 @@ func (p *Parser) lexStart() (lexer.StateFn, error) {
r, _, err := p.src.ReadRune()
switch {
case err != nil:
// read error
return p.emitError("", err)
err = p.emitError("", err)
return nil, err
case IsNewLine(r):
// new line
p.lexNewLine(r)
p.stepLine()
case IsSpace(r):
// whitespace
p.stepRune()
default:
// token
p.src.UnreadRune()
return p.lexToken, nil
}
}
}
func (p *Parser) lexToken() (lexer.StateFn, error) {
p.src.AcceptAll(IsNotSpace)
p.pushString(TokenUnknown)
return p.lexStart, nil
}
func (p *Parser) lexNewLine(r1 rune) {
// r1 is warrantied to be either \n or \r
// r1 is warrantied to be either '\r' or '\n'
r2, _, err := p.src.ReadRune()
switch r1 {
case '\r':
switch {
case r2 == '\n':
// CR LN
case err == nil:
// CR
p.src.UnreadRune()
default:
// CR EOF
}
case '\n':
switch {
case r2 == '\r':
@@ -67,7 +43,24 @@ func (p *Parser) lexNewLine(r1 rune) {
default:
// LN EOF
}
case '\r':
switch {
case r2 == '\n':
// CR LN
case err == nil:
// CR
p.src.UnreadRune()
default:
// CR EOF
}
default:
panic("unreachable")
}
}
func (p *Parser) lexToken() (lexer.StateFn, error) {
p.src.AcceptAll(IsNotSpace)
err := p.emitString(TokenUnknown)
return p.lexStart, err
}
-15
View File
@@ -1,15 +0,0 @@
package parser
import "asciigoat.org/core/lexer"
func (p *Parser) emitError(content string, err error) (lexer.StateFn, error) {
err2 := p.OnError(p.pos, content, err)
switch {
case err2 != nil:
// return wrapped error
return nil, err2
default:
// return original error
return nil, err
}
}
-44
View File
@@ -1,44 +0,0 @@
package parser
import "log"
func (p *Parser) push(tok Token) {
n := len(p.queue)
p.queue = append(p.queue, tok)
log.Printf("queue[%v]: %s", n, tok)
}
func (p *Parser) pushString(typ TokenType) {
s := p.src.Emit()
el := Token{
Type: typ,
Value: s,
Position: p.pos,
}
p.pos.StepN(len(s))
p.push(el)
}
// stepLine discards the data and moves the position
// to the next line
func (p *Parser) stepLine() {
p.src.Discard()
p.pos.StepLine()
}
// stepRune discards the data and moves the position
// on rune forward on the same line
func (p *Parser) stepRune() {
p.src.Discard()
p.pos.Step()
}
func (p *Parser) stepString() string {
s := p.src.Emit()
p.pos.StepN(len(s))
return s
}
+12 -15
View File
@@ -1,19 +1,16 @@
package parser
import "asciigoat.org/core/lexer"
var (
// IsNewLine tells if a rune represents a line break or the start of one
IsNewLine = lexer.NewIsIn("\n\r")
// IsSpace tells if a rune is considered whitespace by unicode
IsSpace = lexer.IsSpace
// IsNotNewLine tells if a rune is anything other than line breaks
IsNotNewLine = lexer.NewIsNot(IsNewLine)
// IsNotSpace tells if a rune is anything other than whitespace
IsNotSpace = lexer.NewIsNot(IsSpace)
import (
"asciigoat.org/core/lexer"
)
// IsSpaceNotNewLine indicates a rune is whitespace but not a new line
func IsSpaceNotNewLine(r rune) bool {
return IsSpace(r) && !IsNewLine(r)
}
var (
// IsNewLine tells if the rune indicates a line break or the start of one
IsNewLine = lexer.NewIsIn("\r\n")
// IsNotNewLine tells if the rune is not a line break nor the start of one
IsNotNewLine = lexer.NewIsNot(IsNewLine)
// IsSpace tells if the rune is considered whitespace by Unicode
IsSpace = lexer.IsSpace
// IsNotSpace tells if the rune is not considered whitespace by Unicode
IsNotSpace = lexer.NewIsNot(IsSpace)
)
+65 -36
View File
@@ -3,6 +3,7 @@ package parser
import (
"io"
"log"
"asciigoat.org/core/lexer"
)
@@ -10,61 +11,89 @@ import (
// Parser parses a dosini-style document
type Parser struct {
src *lexer.Reader
pos lexer.Position
pos lexer.Position
queue []Token
// OnToken is called for each identified token. if it returns an error
// parsing is interrupted.
OnToken func(pos lexer.Position, typ TokenType, value string) error
// OnSection is called after a [section] is parsed.
// Returning an error will abort the process.
OnSection func(pos lexer.Position, name, subname string, hasSubname bool) error
// OnField is called after a `key = value` entry is parsed
// Returning an error will abort the process.
OnField func(pos lexer.Position, key, value string) error
// OnComment is called after a comment is parsed
// Returning an error will abort the process.
OnComment func(pos lexer.Position, comment string) error
// OnError is called after each parsing error, which you are allowed to
// override.
// OnError is called for EOF as well, but this error isn't returned as such by
// Parser.Run(). The caller will receive (nil, nil) instead indicating the
// processes terminated correctly.
// OnError is called in case of a parsing error, and it's allowed
// to replace the error returned by [Parser.Run].
// OnError is called for io.EOF, but [Parser.Run] will consider it
// normal termination.
OnError func(pos lexer.Position, content string, err error) error
}
func defaultOnSection(_ lexer.Position, _, _ string, _ bool) error { return nil }
func defaultOnField(_ lexer.Position, _, _ string) error { return nil }
func defaultOnComment(_ lexer.Position, _ string) error { return nil }
func defaultOnToken(pos lexer.Position, typ TokenType, value string) error {
log.Printf("%s:%v:%v: %q", typ, pos.Line, pos.Column, value)
return nil
}
func defaultOnError(pos lexer.Position, content string, err error) error {
return &lexer.Error{
Line: pos.Line,
Column: pos.Column,
log.Printf("%s:%v:%v: %q: %s", "error", pos.Line, pos.Column, content, err)
return lexer.Error{
Line: pos.Line,
Column: pos.Column,
Content: content,
Err: err,
}
}
func (p *Parser) setDefaults() {
if p.OnSection == nil {
p.OnSection = defaultOnSection
if p.OnToken == nil {
p.OnToken = defaultOnToken
}
if p.OnField == nil {
p.OnField = defaultOnField
}
if p.OnComment == nil {
p.OnComment = defaultOnComment
}
if p.OnError == nil {
p.OnError = defaultOnError
}
}
func (p *Parser) emitString(typ TokenType) error {
var err error
s := p.src.Emit()
err = p.OnToken(p.pos, typ, s)
p.pos.StepN(len(s))
return err
}
func (p *Parser) emitError(content string, err error) error {
err2 := p.OnError(p.pos, content, err)
switch {
case err2 != nil:
// return wrapped error
return err2
default:
// return original error
return err
}
}
// stepLine discards the data and moves the position
// to the next line.
func (p *Parser) stepLine() {
p.src.Discard()
p.pos.StepLine()
}
// stepRune discards the data and moves the position
// one rune forward on the same line.
func (p *Parser) stepRune() {
p.src.Discard()
p.pos.Step()
}
// stepString discards the data and moves the position
// forward on the same line the length of the discarded
// content.
func (p *Parser) stepString() {
s := p.src.Emit()
p.pos.StepN(len(s))
}
// NewParser creates a dosini-style parser using
// an [io.Reader] as source
func NewParser(r io.Reader) *Parser {
+7 -17
View File
@@ -1,11 +1,6 @@
package parser
//go:generate go run golang.org/x/tools/cmd/stringer -type=TokenType
import (
"fmt"
"asciigoat.org/core/lexer"
)
// A TokenType is a type of Token
type TokenType uint
@@ -13,6 +8,12 @@ type TokenType uint
const (
// TokenUnknown represents a Token that hasn't been identified
TokenUnknown TokenType = iota
// TokenSectionStart indicates the opening marker of a section declaration.
// The left squared bracket.
TokenSectionStart
// TokenSectionEnd indicates the closing marker of a section declaration.
// The right squared bracket.
TokenSectionEnd
// TokenSectionName represents the section name between the squared brackets
TokenSectionName
// TokenSectionSubname represents a secondary name in the section represented
@@ -21,21 +22,10 @@ const (
// [section_name "section_subname"]
TokenSectionSubname
// TokenComment represents a comment, including the initial ';' or '#' until
// the end of the line
// the end of the line.
TokenComment
// TokenFieldKey represents a field name in a `key = value` entry
TokenFieldKey
// TokenFieldValue represents a field value in a `key = value` entry
TokenFieldValue
)
// A Token is an element from the document
type Token struct {
Type TokenType
Position lexer.Position
Value string
}
func (t Token) String() string {
return fmt.Sprintf("%s:%v:%v: %q", t.Type, t.Position.Line, t.Position.Column, t.Value)
}
+9 -7
View File
@@ -9,16 +9,18 @@ func _() {
// Re-run the stringer command to generate them again.
var x [1]struct{}
_ = x[TokenUnknown-0]
_ = x[TokenSectionName-1]
_ = x[TokenSectionSubname-2]
_ = x[TokenComment-3]
_ = x[TokenFieldKey-4]
_ = x[TokenFieldValue-5]
_ = x[TokenSectionStart-1]
_ = x[TokenSectionEnd-2]
_ = x[TokenSectionName-3]
_ = x[TokenSectionSubname-4]
_ = x[TokenComment-5]
_ = x[TokenFieldKey-6]
_ = x[TokenFieldValue-7]
}
const _TokenType_name = "TokenUnknownTokenSectionNameTokenSectionSubnameTokenCommentTokenFieldKeyTokenFieldValue"
const _TokenType_name = "TokenUnknownTokenSectionStartTokenSectionEndTokenSectionNameTokenSectionSubnameTokenCommentTokenFieldKeyTokenFieldValue"
var _TokenType_index = [...]uint8{0, 12, 28, 47, 59, 72, 87}
var _TokenType_index = [...]uint8{0, 12, 29, 44, 60, 79, 91, 104, 119}
func (i TokenType) String() string {
if i >= TokenType(len(_TokenType_index)-1) {