From 70f3968fb342b37cea93f185917578fd2e548a26 Mon Sep 17 00:00:00 2001
From: Alejandro Mery <amery@jpi.io>
Date: Tue, 29 Aug 2023 00:21:36 +0000
Subject: [PATCH] basic: WIP

Signed-off-by: Alejandro Mery <amery@jpi.io>
---
 README.md        |  9 ++++++
 basic/basic.go   |  2 ++
 basic/decoder.go | 73 ++++++++++++++++++++++++++++++++++++++++++++++++
 basic/types.go   | 23 +++++++++++++++
 4 files changed, 107 insertions(+)
 create mode 100644 basic/basic.go
 create mode 100644 basic/decoder.go
 create mode 100644 basic/types.go

diff --git a/README.md b/README.md
index 7a27335..86a0f55 100644
--- a/README.md
+++ b/README.md
@@ -16,6 +16,7 @@ of stricter parsers of similar form.
 
 [godoc-lexer]: https://pkg.go.dev/asciigoat.org/core/lexer
 [godoc-parser-parser]: https://pkg.go.dev/asciigoat.org/ini/parser#Parser
+[godoc-basic-parser]: https://pkg.go.dev/asciigoat.org/ini/basic#Decode
 
 [wikipedia-dosini]: https://en.wikipedia.org/wiki/INI_file
 
@@ -25,6 +26,14 @@ of stricter parsers of similar form.
 [`asciigoat`'s lexer][godoc-lexer] to process an `INI`-style document
 emiting tokens and errors via callbacks.
 
+## Basic Parser
+
+[`basic.Decode()`][godoc-basic-parser] provies a one-shot decoder
+that returns a structured document for you to post-process.
+
+To allow for correct handling of repetition of section and field names downstream, it uses arrays instead of maps, and makes almost no judgment
+about what section or field names are acceptable.
+
 ## Other Implementations
 
 * [gcfg](https://pkg.go.dev/gopkg.in/gcfg.v1)
diff --git a/basic/basic.go b/basic/basic.go
new file mode 100644
index 0000000..6942abe
--- /dev/null
+++ b/basic/basic.go
@@ -0,0 +1,2 @@
+// Package basic provides a basic representation of dosini-style documents
+package basic
diff --git a/basic/decoder.go b/basic/decoder.go
new file mode 100644
index 0000000..894fdc1
--- /dev/null
+++ b/basic/decoder.go
@@ -0,0 +1,73 @@
+package basic
+
+import (
+	"bytes"
+	"io"
+	"io/fs"
+	"log"
+	"strings"
+
+	"asciigoat.org/core/lexer"
+	"asciigoat.org/ini/parser"
+)
+
+type token struct {
+	pos   lexer.Position
+	typ   parser.TokenType
+	value string
+}
+
+type decoder struct {
+	p   *parser.Parser
+	out *Document
+
+	queue      []token
+	curSection *Section
+	curField   *Field
+}
+
+func (dec *decoder) OnToken(pos lexer.Position, typ parser.TokenType, value string) error {
+	tok := token{pos, typ, value}
+
+	log.Printf("%s[%v]: %s %s: %q", "decoder", len(dec.queue), pos, typ, value)
+
+	dec.queue = append(dec.queue, tok)
+
+	return nil
+}
+
+func (*decoder) OnError(pos lexer.Position, hint string, err error) error {
+	log.Printf("%s: %s %s: %s: %v", "decoder", pos, "error", hint, err)
+	return err
+}
+
+// Decode ...
+func Decode(r io.Reader) (*Document, error) {
+	var out Document
+
+	if r == nil {
+		return nil, fs.ErrNotExist
+	}
+
+	// parser
+	p := parser.NewParser(r)
+	// decoder
+	dec := decoder{p: p, out: &out}
+	// glue
+	p.OnToken = dec.OnToken
+	p.OnError = dec.OnError
+
+	// Go!
+	err := p.Run()
+	return &out, err
+}
+
+// DecodeBytes ...
+func DecodeBytes(b []byte) (*Document, error) {
+	return Decode(bytes.NewReader(b))
+}
+
+// DecodeString ...
+func DecodeString(s string) (*Document, error) {
+	return Decode(strings.NewReader(s))
+}
diff --git a/basic/types.go b/basic/types.go
new file mode 100644
index 0000000..daf61bd
--- /dev/null
+++ b/basic/types.go
@@ -0,0 +1,23 @@
+package basic
+
+// Document ...
+type Document struct {
+	Global []Field
+
+	Sections []Section
+}
+
+// Section ...
+type Section struct {
+	Name   string
+	Key    string
+	HadKey bool
+
+	Fields []Field
+}
+
+// Field ...
+type Field struct {
+	Key   string
+	Value string
+}