Reference · Files and processes

check_program

check_program(str, map | null=) -> list | error(str)

What it does

What quillo check says of a program, as a list of { file, line, severity, message } maps, severity being "error" or "warning"; an empty list means the program is fine. The path is from the program's folder. The map gives some files' text in place of what is on disk, keyed by path, so a tool that writes Quillo code (a plugin editor, a form's rule) can check it before saving it. The code checked may come from users, so it reads nothing outside the program's folder, and inside it only Quillo's files.

Examples

write_file("plugins/greet.qwe", "fn greet(n: str) = upper(n)\nprint(greet(1))\n")print(check_program("plugins/greet.qwe"))print(check_program("plugins/greet.qwe", { "plugins/greet.qwe": "fn greet(n: str) = upper(n)\nprint(greet(\"ann\"))\n" }))

[{ file: "plugins/greet.qwe", line: 2, severity: "error", message: "argument `n` of `greet` must be str, got int" }][]

Edge cases

• Several problems come as several maps, each with its line; filter on severity keeps the errors.
• A file that does not exist is not an error value: it is a list with one error at line 0 saying the file cannot be read.
• A use in the checked code with .. or starting at / is reported as an error on that line, not followed. So is a use of a plain path that leads out of the folder through a link: nothing is read there.
• It reads only .qwe files (and the signatures of .qwer and .rs files for a use), none with a dot folder or file in its path, and a link is judged by where it leads: use ".env" or use ".git/config" is an error on that line, and reads nothing. Its messages never show a file's text.
• The path itself, or a key of the map, that leaves the folder, or is not a Quillo file, is an error value.
• null as the map checks what is on disk; an empty override checks an empty program, which is fine.

write_file("plugins/p.qwe", "print(len(3))\nprint(nope)\nfn upper(s: str) = s\n")print(check_program("plugins/p.qwe") | map((d) => `${d.severity} ${d.line}: ${d.message}`))print(check_program("plugins/p.qwe") | filter((d) => d.severity == "error") | len)print(check_program("nope.qwe"))print(check_program("plugins/p.qwe", { "plugins/p.qwe": "use \"../secret.qwe\"\n" }))print(check_program("../main.qwe"))print(check_program("plugins/p.qwe", { "../y.qwe": "" }))print(check_program("plugins/p.qwe", null) | len, check_program("plugins/p.qwe", { "plugins/p.qwe": "" }))print(check_program("p.qwe", { "p.qwe": "use \".env\"\n" }) | map((d) => d.message))

["error 1: argument 1 of `len` must be str | list | map | html | null, got int", "error 2: unknown name `nope` (did you mean `now`?)", "warning 3: `upper` hides the builtin `upper`: the program's own is used everywhere, so pick another name"]2[{ file: "nope.qwe", line: 0, severity: "error", message: "cannot read file: No such file or directory (os error 2)" }][{ file: "plugins/p.qwe", line: 1, severity: "error", message: "path must stay inside the program's folder: ../secret.qwe" }]err("check_program: path must stay inside the program's folder: ../main.qwe")err("check_program: path must stay inside the program's folder: ../y.qwe")3 []["only Quillo files are read (.qwe, and a plugin's .qwer or .rs for `use`), none whose name or folder starts with a dot: .env"]

Errors

A path outside the folder, or of a file that is not Quillo's, is an error value; what the checker finds is never one, it is the list. A path that is not a string is a runtime error.

print(check_program(1))

line 1: `check_program` expects a str as argument 1, got int

Chaining

The path comes first in a pipeline:

write_file("plugins/ok.qwe", "print(1)\n")print(("plugins/ok.qwe" | check_program | len) == 0)let bad = "plugins/ok.qwe" | check_program({ "plugins/ok.qwe": "print(" })print(bad | map((d) => d.message))

true["expected an expression, found end of input"]

See also

run_script, read_file, write_file

Edit this page on GitHub · every example's output was made by running it (tools/refcheck.mjs) · questions on Discord or r/quillo