feat: scaffold interpres project with TOML parser and CI

README.md

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+# interpres
+
+A dependency-free **TOML 1.0 parser for Go** — standard library only, no
+third-party modules. Passes the entire
+[toml-test](https://github.com/toml-lang/toml-test) suite (185 valid and 371
+invalid cases).
+
+`interpres` (Latin for *interpreter*) reads TOML documents into Go values with a
+small, `encoding/json`-style API. It is built for embedding in zero-dependency
+Go programs that still want their configuration in TOML.
+
+## Install
+
+```sh
+go get codeberg.org/petrbalvin/interpres
+```
+
+Requires Go 1.26 or newer. The module imports only the standard library.
+
+## Usage
+
+### Decode into a struct
+
+```go
+package main
+
+import (
+	"fmt"
+
+	"codeberg.org/petrbalvin/interpres"
+)
+
+type Config struct {
+	Title  string `toml:"title"`
+	Server struct {
+		Host string `toml:"host"`
+		Port int    `toml:"port"`
+	} `toml:"server"`
+}
+
+func main() {
+	data := []byte(`
+title = "example"
+
+[server]
+host = "127.0.0.1"
+port = 9090
+`)
+
+	var cfg Config
+	if err := interpres.Unmarshal(data, &cfg); err != nil {
+		panic(err)
+	}
+	fmt.Printf("%+v\n", cfg)
+}
+```
+
+### Untyped tree
+
+```go
+tree, err := interpres.Parse(data) // map[string]any
+```
+
+### Strict decoding
+
+Reject keys that have no matching struct field — useful for catching typos in
+configuration files:
+
+```go
+err := interpres.NewDecoder().
+	DisallowUnknownFields().
+	Decode(data, &cfg)
+```
+
+## Struct mapping
+
+Fields are matched to TOML keys by the `toml:"name"` tag, or by a
+case-insensitive match on the field name when no tag is present. A tag of `"-"`
+skips the field.
+
+| TOML value | Go type (untyped tree) |
+|------------|------------------------|
+| string | `string` |
+| integer | `int64` |
+| float | `float64` |
+| boolean | `bool` |
+| offset date-time | `time.Time` |
+| local date-time | `LocalDateTime` |
+| local date | `LocalDate` |
+| local time | `LocalTime` |
+| array | `[]any` |
+| table / inline table | `map[string]any` |
+| array of tables | `[]map[string]any` |
+
+When decoding into a struct, these map onto the destination's concrete types
+(any integer/unsigned/float width, slices, nested structs, and `map[string]T`).
+
+## TOML 1.0 support
+
+`interpres` implements the full [TOML 1.0](https://toml.io/en/v1.0.0) grammar:
+
+- Comments, and bare / quoted / dotted keys.
+- Tables `[a.b]` and arrays of tables `[[a]]`.
+- Basic and literal strings, including multiline (`"""` / `'''`) with escape
+  sequences (`\n`, `\t`, `\uXXXX`, `\UXXXXXXXX`, line-ending backslash).
+- Integers in decimal, hex (`0x`), octal (`0o`), and binary (`0b`) with `_`
+  separators; floats with exponents and `inf` / `nan`.
+- Booleans, offset/local date-times, dates, and times.
+- Arrays (multiline, mixed types) and inline tables.
+
+Invalid documents are rejected per the specification (malformed numbers and
+floats, control characters, non-UTF-8 input, out-of-range escapes, table and
+inline-table redefinitions, and more).
+
+## Compliance
+
+The parser is verified against the official
+[toml-test](https://github.com/toml-lang/toml-test) suite via
+`cmd/interpres-decode`:
+
+```sh
+go build -o interpres-decode ./cmd/interpres-decode
+toml-test ./interpres-decode
+```
+
+## License
+
+MIT — see [LICENSE](LICENSE).
+Copyright © 2026 [Petr Balvín](https://petrbalvin.org)