6 Commits

Author SHA1 Message Date
amery 23a6bd090c build-sys: use local darvaza.org/core [DO-NOT-MERGE]
Signed-off-by: Alejandro Mery <amery@jpi.io>
2023-09-03 17:03:48 +00:00
amery f8fa9d678a build-sys: use local asciigoat.org/core [DO-NOT-MERGE]
Signed-off-by: Alejandro Mery <amery@jpi.io>
2023-09-03 17:03:48 +00:00
amery 7e2797607d Merge branch 'pr-amery-textparser' into next-amery 2023-09-03 17:02:51 +00:00
amery 01cd4139bd parser.Parser: refactor using TextParser
Signed-off-by: Alejandro Mery <amery@jpi.io>
2023-09-03 17:01:26 +00:00
amery e34e8eda0a parser.TextParser: AcceptNewLine() and AcceptRune()
Signed-off-by: Alejandro Mery <amery@jpi.io>
2023-09-03 17:01:26 +00:00
amery ecff6f6016 parser: introduce generic-ish TextParser
Signed-off-by: Alejandro Mery <amery@jpi.io>
2023-09-03 17:01:26 +00:00
3 changed files with 135 additions and 73 deletions
+17 -46
View File
@@ -5,71 +5,42 @@ import "asciigoat.org/core/lexer"
// Run parses the source
func (p *Parser) Run() error {
p.setDefaults()
p.pos.Reset()
return lexer.Run(p.lexStart)
}
func (p *Parser) lexStart() (lexer.StateFn, error) {
for {
r, _, err := p.src.ReadRune()
r, _, err := p.p.ReadRune()
switch {
case err != nil:
return p.emitError("", err)
case IsNewLine(r):
// new line
p.lexMoreNewLine(r)
p.p.UnreadRune()
p.p.AcceptNewLine()
p.stepLine()
case IsSpace(r):
// whitespace
p.stepRune()
p.stepString()
case IsCommentStart(r):
// switch to comment lexer
p.src.UnreadRune()
p.p.UnreadRune()
return p.lexComment, nil
case IsSectionStart(r):
// section
return p.lexSectionStart, nil
default:
// entry
p.src.UnreadRune()
p.p.UnreadRune()
return p.lexEntryStart, nil
}
}
}
func (p *Parser) lexMoreNewLine(r1 rune) {
// r1 is warrantied to be either '\r' or '\n'
r2, _, err := p.src.ReadRune()
switch r1 {
case '\n':
switch {
case r2 == '\r':
// LN CR
case err == nil:
// LN
p.src.UnreadRune()
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) lexComment() (lexer.StateFn, error) {
// until the end of the line
p.src.AcceptAll(IsNotNewLine)
p.p.AcceptAll(IsNotNewLine)
err := p.emitString(TokenComment)
return p.lexStart, err
@@ -81,11 +52,11 @@ func (p *Parser) lexSectionStart() (lexer.StateFn, error) {
}
// remove whitespace between `[` and the name
if p.src.AcceptAll(IsSpaceNotNewLine) {
if p.p.AcceptAll(IsSpaceNotNewLine) {
p.stepString()
}
if !p.src.AcceptAll(IsName) {
if !p.p.AcceptAll(IsName) {
// no name
return p.emitError("section name missing", lexer.ErrUnacceptableRune)
}
@@ -94,12 +65,12 @@ func (p *Parser) lexSectionStart() (lexer.StateFn, error) {
return nil, err
}
// remove whitespace between the name andthe closing `]`
if p.src.AcceptAll(IsSpaceNotNewLine) {
// remove whitespace between the name and the closing `]`
if p.p.AcceptAll(IsSpaceNotNewLine) {
p.stepString()
}
r, _, err := p.src.ReadRune()
r, _, err := p.p.ReadRune()
switch {
case err != nil:
return p.emitError("", err)
@@ -112,17 +83,17 @@ func (p *Parser) lexSectionStart() (lexer.StateFn, error) {
}
func (p *Parser) lexEntryStart() (lexer.StateFn, error) {
p.src.AcceptAll(IsName)
p.p.AcceptAll(IsName)
if err := p.emitString(TokenFieldKey); err != nil {
return nil, err
}
// ignore whitespace between key and the '=' sign
if p.src.AcceptAll(IsSpaceNotNewLine) {
if p.p.AcceptAll(IsSpaceNotNewLine) {
p.stepString()
}
r, _, err := p.src.ReadRune()
r, _, err := p.p.ReadRune()
switch {
case err != nil:
return p.emitError("", err)
@@ -131,11 +102,11 @@ func (p *Parser) lexEntryStart() (lexer.StateFn, error) {
}
// ignore whitespace between the '=' and the value
if p.src.AcceptAll(IsSpaceNotNewLine) {
if p.p.AcceptAll(IsSpaceNotNewLine) {
p.stepString()
}
p.src.AcceptAll(IsNotNewLine)
p.p.AcceptAll(IsNotNewLine)
if err := p.emitString(TokenFieldValue); err != nil {
return nil, err
}
+16 -27
View File
@@ -1,4 +1,4 @@
// Package parser parses dosini-style files
// Package parser parses ini-style files
package parser
import (
@@ -8,10 +8,9 @@ import (
"asciigoat.org/core/lexer"
)
// Parser parses a dosini-style document
// Parser parses a ini-style document
type Parser struct {
src *lexer.Reader
pos lexer.Position
p TextParser
// OnToken is called for each identified token. if it returns an error
// parsing is interrupted.
@@ -51,15 +50,13 @@ func (p *Parser) setDefaults() {
}
func (p *Parser) emitString(typ TokenType) error {
s := p.src.Emit()
err := p.OnToken(p.pos, typ, s)
p.pos.StepN(len(s))
return err
pos, s := p.p.Emit()
return p.OnToken(pos, typ, s)
}
func (p *Parser) emitError(content string, err error) (lexer.StateFn, error) {
err2 := p.OnError(p.pos, content, err)
pos := p.p.Position()
err2 := p.OnError(pos, content, err)
switch {
case err2 != nil:
// return wrapped error
@@ -77,33 +74,25 @@ func (p *Parser) emitInvalidRune(r rune) (lexer.StateFn, error) {
// 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()
p.p.StepLine()
}
// 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))
p.p.Step()
}
// NewParser creates a dosini-style parser using
// NewParser creates a ini-style parser using
// an [io.Reader] as source
func NewParser(r io.Reader) *Parser {
if r == nil {
return nil
var p *Parser
if r != nil {
p = new(Parser)
p.p.Init(r)
}
return &Parser{
src: lexer.NewReader(r),
}
return p
}
+102
View File
@@ -0,0 +1,102 @@
package parser
import (
"bytes"
"io"
"strings"
"asciigoat.org/core/lexer"
)
// TextParser is a generic text parser.
type TextParser struct {
*lexer.Reader
pos lexer.Position
}
// Init initializes the [TextParser] with a non-nil [io.Reader].
func (p *TextParser) Init(r io.Reader) {
switch {
case p == nil || r == nil:
panic("invalid call")
case p.Reader != nil:
panic("parser already initialized")
default:
p.Reader = lexer.NewReader(r)
p.pos.Reset()
}
}
// InitBytes initializes the [TextParser] with a byte array
func (p *TextParser) InitBytes(b []byte) {
p.Init(bytes.NewReader(b))
}
// InitString initializes the [TextParser] with a byte array
func (p *TextParser) InitString(s string) {
p.Init(strings.NewReader(s))
}
// Discard shadows [lexer.Reader]'s, and takes in consideration
// new lines on the discarded data when moving the position
func (*TextParser) Discard() {
// TODO: consider new lines
panic("not implemented")
}
// Emit returns the accepted text, its position, and
// moves the cursor position accordingly
func (p *TextParser) Emit() (lexer.Position, string) {
pos := p.pos
s := p.Reader.Emit()
// TODO: consider new lines
p.pos.StepN(len(s))
return pos, s
}
// Step discards what's been accepted and increments the
// position assuming they all increment the column counter
func (p *TextParser) Step() {
s := p.Reader.Emit()
p.pos.StepN(len(s))
}
// StepLine discards what's been accepted and moves then
// position to the beginning of the next line
func (p *TextParser) StepLine() {
p.Reader.Discard()
p.pos.StepLine()
}
// Position returns the position of the first character
// of the accepted text
func (p *TextParser) Position() lexer.Position {
return p.pos
}
// AcceptNewLine checks if next is a new line.
// It accepts "\n", "\n\r", "\r" and "\r\n".
func (p *TextParser) AcceptNewLine() bool {
r1, _, err := p.ReadRune()
switch {
case err != nil:
return false
case r1 == '\n':
p.AcceptRune('\r')
return true
case r1 == '\r':
p.AcceptRune('\n')
return true
default:
p.UnreadRune()
return false
}
}
// AcceptRune checks if next is the specified rune
func (p *TextParser) AcceptRune(r rune) bool {
return p.Accept(func(r2 rune) bool {
return r == r2
})
}