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|
//// ocda-lib, in Gleam: the abstraction as a library, put to the question.
////
//// A library has no binary, so this is the programs over it: the reader,
//// and the two that test its claims.
////
//// ocda-lib dump [--unknown] <file>.ssp|<file>.ocda.db [lang]
//// ocda-lib agree <doc>.ssp <doc>.ocda.db [lang]
//// ocda-lib read [options] <file> [lang] (also installed as ocda-read)
////
//// `dump` writes the whole loaded model out canonically, byte for byte as
//// the D library's `ocda-dump` writes it, so that the two implementations
//// can be diffed. `agree` asks the same question the D library's
//// `ocda-agree` asks, within this language: does loading a document's
//// `.ssp` give what loading its `.ocda.db` gives?
import argv
import gleam/int
import gleam/io
import gleam/list
import gleam/string
import ocda/dump
import ocda/load
import ocda/model.{type Document}
import read/main as reader
pub fn main() {
case argv.load().arguments {
["dump", "--unknown", path] -> dump_file(path, "", True)
["dump", "--unknown", path, lang] -> dump_file(path, lang, True)
["dump", path] -> dump_file(path, "", False)
["dump", path, lang] -> dump_file(path, lang, False)
["agree", ssp, db] -> agree(ssp, db, "")
["agree", ssp, db, lang] -> agree(ssp, db, lang)
["read", ..rest] ->
case reader.run(rest) {
0 -> Nil
code -> halt(code)
}
_ -> usage()
}
}
fn usage() -> Nil {
io.println_error(
"usage: ocda-lib dump [--unknown] <file>.ssp|<file>.ocda.db [lang]
ocda-lib agree <doc>.ssp <doc>.ocda.db [lang]
ocda-lib read [--help] [options] <file> [lang]",
)
halt(2)
}
fn dump_file(path: String, lang: String, unknown: Bool) -> Nil {
case load.load(path, lang, False) {
Error(message) -> fail(message)
Ok(doc) ->
case unknown {
True -> io.print(dump.unknown(doc))
False -> io.print(dump.document(doc))
}
}
}
/// The library's whole purpose is that a writer cannot tell which
/// serialisation it was handed. That is only true if the two loaders give
/// the same model, so this asks, and says where they part company rather
/// than only that they did.
fn agree(ssp_path: String, db_path: String, lang: String) -> Nil {
case load.load(ssp_path, "", False), load.load(db_path, lang, False) {
Error(message), _ -> fail(message)
_, Error(message) -> fail(message)
Ok(from_ssp), Ok(from_db) -> {
let differences = compare(from_ssp, from_db)
case differences {
[] -> io.println("agree: the two loaders give the same model")
_ -> {
list.each(list.take(differences, 12), io.println)
case list.length(differences) > 12 {
True -> io.println(" ... stopping after 12")
False -> Nil
}
io.println(int.to_string(list.length(differences)) <> " difference(s)")
halt(1)
}
}
}
}
}
/// Compared through the dump rather than field by field, which is both
/// shorter and stricter: the dump carries every field, so nothing can
/// differ without showing here.
fn compare(from_ssp: Document, from_db: Document) -> List(String) {
let a = dump.document(from_ssp)
let b = dump.document(from_db)
case a == b {
True -> []
False -> diff_lines(a, b)
}
}
fn diff_lines(a: String, b: String) -> List(String) {
let la = split_lines(a)
let lb = split_lines(b)
case list.length(la) == list.length(lb) {
False -> [
" differ: line count",
" .ssp: " <> int.to_string(list.length(la)),
" .ocda.db: " <> int.to_string(list.length(lb)),
..pairwise(la, lb)
]
True -> pairwise(la, lb)
}
}
fn pairwise(la: List(String), lb: List(String)) -> List(String) {
list.zip(la, lb)
|> list.index_map(fn(pair, i) { #(i, pair.0, pair.1) })
|> list.filter(fn(t) { t.1 != t.2 })
|> list.map(fn(t) {
" differ: line "
<> int.to_string(t.0 + 1)
<> "\n .ssp: "
<> t.1
<> "\n .ocda.db: "
<> t.2
})
}
fn split_lines(text: String) -> List(String) {
case text {
"" -> []
_ -> string.split(text, on: "\n")
}
}
fn fail(message: String) -> Nil {
io.println_error("error: " <> message)
halt(2)
}
/// Gleam has no standard exit, and the exit status is what a sweep script
/// reads.
@external(erlang, "erlang", "halt")
fn halt(code: Int) -> Nil
|
