use std::io;
use std::path::PathBuf;
use anstream::AutoStream;
use super::exit_status::ExitStatus;
use super::program_file::ProgramFile;
use super::standard_error::StandardError;
use super::terminal::Terminal;
use super::token_colors::TokenColors;
use crate::core::{BindingId, Expr, ExprKind, Leaf, Literal};
use crate::diagnostic::Diagnostics;
use crate::expand::{ExpansionSession, Program};
use crate::language::Language;
use crate::reader::{Form, FormKind, Symbol};
use crate::source::{SourceId, Span};
use crate::types::TypedProgram;
pub struct DocCommand {
environment: DocEnvironment,
term: String,
page: DocPage,
}
pub enum DocPage {
Written,
Typed,
}
impl DocCommand {
pub const NAME: &'static str = "doc";
const SEPARATOR: &'static str = "--";
pub fn usage() -> String {
let command = format!("{} {}", Language::NAME, Self::NAME);
format!(
"{command} [OPTIONS] <TERM>\n {command} [OPTIONS] {} <TERM>",
Self::SEPARATOR
)
}
pub fn new(environment: DocEnvironment, term: String, page: DocPage) -> Self {
Self {
environment,
term,
page,
}
}
pub fn run(self, terminal: &mut Terminal) -> ExitStatus {
let mut lookup = DocLookup::new(terminal);
let output = match self.page {
DocPage::Written => lookup
.describe(&self.environment, &self.term)
.map(DocOutput::page),
DocPage::Typed => lookup.describe_with_type(&self.environment, &self.term),
};
let colors = TokenColors::deciding(AutoStream::choice(&io::stdout()));
match output {
Ok(output) => output.print(terminal, colors),
Err(status) => status,
}
}
}
struct PageText {
header: String,
body: String,
}
impl PageText {
fn painted(&self, colors: TokenColors) -> String {
format!("{}{}", colors.paint(&self.header), self.body)
}
}
struct DocOutput {
type_line: Option<String>,
page: PageText,
status: ExitStatus,
}
impl DocOutput {
fn page(page: PageText) -> Self {
Self {
type_line: None,
page,
status: ExitStatus::Success,
}
}
fn typed(page: PageText, type_line: Result<Option<String>, ExitStatus>) -> Self {
match type_line {
Ok(type_line) => Self {
type_line,
..Self::page(page)
},
Err(status) => Self {
status,
..Self::page(page)
},
}
}
fn print(&self, terminal: &Terminal, colors: TokenColors) -> ExitStatus {
match terminal.write_output(self.text(colors)) {
ExitStatus::Success => self.status,
failure => failure,
}
}
fn text(&self, colors: TokenColors) -> String {
self.type_line
.iter()
.map(|type_line| colors.paint(type_line))
.chain([self.page.painted(colors)])
.map(|line| format!("{line}\n"))
.collect()
}
}
pub struct DocLookup<'t> {
terminal: &'t mut Terminal,
}
impl<'t> DocLookup<'t> {
const TERM_SOURCE: &'static str = "<term>";
const HEADER_MACRO: &'static str = "doc-header";
const BODY_MACRO: &'static str = "doc-body";
pub fn new(terminal: &'t mut Terminal) -> Self {
Self { terminal }
}
fn describe(
&mut self,
environment: &DocEnvironment,
term: &str,
) -> Result<PageText, ExitStatus> {
let read = self.read_term(term)?;
let entry = environment.load(self.terminal)?;
let expanded =
self.terminal
.within_session(&environment.file(), entry, |mut session| {
let source = session.add_source(Self::TERM_SOURCE, term);
ExpandedPage::expand(&mut session, &read, source)
})?;
expanded.text()
}
fn describe_with_type(
&mut self,
environment: &DocEnvironment,
term: &str,
) -> Result<DocOutput, ExitStatus> {
let read = self.read_term(term)?;
let entry = environment.load(self.terminal)?;
let lookup = self
.terminal
.within_session(&environment.file(), entry, |session| {
TypedLookup::new(session, (Self::TERM_SOURCE, term)).look_up(&read)
})?;
let page = lookup.page.text()?;
let type_line = self
.terminal
.check_expanded(&lookup.program)
.map(|typed| lookup.type_line(&typed));
Ok(DocOutput::typed(page, type_line))
}
fn read_term(&self, term: &str) -> Result<Form, ExitStatus> {
let forms = self
.terminal
.scratch()
.read_text(Self::TERM_SOURCE, term)
.map_err(|_| ExitStatus::UsageError)?;
match forms.as_slice() {
[form] => Ok(form.clone()),
_ => {
StandardError::write_line(format_args!("error: `{term}` is not one term"));
Err(ExitStatus::UsageError)
}
}
}
fn lookup_call(lookup: &str, term: &Form, source: SourceId) -> Form {
let span = Span::new(source, term.span().range());
let head = Form::new(FormKind::Symbol(Symbol::new(lookup)), span);
Form::new(
FormKind::List(vec![head, Self::relocated(term, source)]),
span,
)
}
fn relocated(form: &Form, source: SourceId) -> Form {
let kind = match form.kind() {
FormKind::List(items) => FormKind::List(
items
.iter()
.map(|item| Self::relocated(item, source))
.collect(),
),
atom => atom.clone(),
};
Form::new(kind, Span::new(source, form.span().range()))
}
}
struct ExpandedPage {
header: Expr,
body: Expr,
}
impl ExpandedPage {
fn expand(
session: &mut ExpansionSession<'_>,
term: &Form,
source: SourceId,
) -> Result<Self, Diagnostics> {
let header = session.expression(DocLookup::lookup_call(
DocLookup::HEADER_MACRO,
term,
source,
))?;
let body =
session.expression(DocLookup::lookup_call(DocLookup::BODY_MACRO, term, source))?;
Ok(Self { header, body })
}
fn text(&self) -> Result<PageText, ExitStatus> {
Ok(PageText {
header: Self::string(&self.header, DocLookup::HEADER_MACRO)?,
body: Self::string(&self.body, DocLookup::BODY_MACRO)?,
})
}
fn same_text(&self, other: &Self) -> bool {
self.literals() == other.literals()
}
fn literals(&self) -> [Option<&str>; 2] {
[Self::literal(&self.header), Self::literal(&self.body)]
}
fn string(expanded: &Expr, lookup: &str) -> Result<String, ExitStatus> {
match Self::literal(expanded) {
Some(text) => Ok(text.to_string()),
None => {
StandardError::write_line(format_args!(
"error: `{lookup}` did not expand to a string"
));
Err(ExitStatus::ProgramErrors)
}
}
}
fn literal(expanded: &Expr) -> Option<&str> {
match expanded.kind() {
ExprKind::Leaf(Leaf::Literal(Literal::String(text))) => Some(text),
_ => None,
}
}
}
struct TypedLookup<'s> {
session: ExpansionSession<'s>,
source: SourceId,
}
impl<'s> TypedLookup<'s> {
fn new(mut session: ExpansionSession<'s>, (name, text): (&str, &str)) -> Self {
let source = session.add_source(name, text);
Self { session, source }
}
fn look_up(mut self, term: &Form) -> Result<TypedPage, Diagnostics> {
let page = self.expand_page(term)?;
let signed = self.signed_binding(term, &page)?;
let mut program = self.session.finish()?;
if let Some(binding) = signed {
program.check_also(binding);
}
Ok(TypedPage {
page,
signed,
program,
})
}
fn signed_binding(
&mut self,
term: &Form,
page: &ExpandedPage,
) -> Result<Option<BindingId>, Diagnostics> {
let binding = self.session.binding(term);
let Some(value_term) = self.session.hide_type(term) else {
return Ok(binding);
};
let value_page = self.expand_page(&value_term)?;
Ok(if value_page.same_text(page) {
binding
} else {
None
})
}
fn expand_page(&mut self, term: &Form) -> Result<ExpandedPage, Diagnostics> {
ExpandedPage::expand(&mut self.session, term, self.source)
}
}
struct TypedPage {
page: ExpandedPage,
signed: Option<BindingId>,
program: Program,
}
impl TypedPage {
fn type_line(&self, typed: &TypedProgram) -> Option<String> {
typed.signature(self.signed?)
}
}
pub enum DocEnvironment {
Prelude,
Program(PathBuf),
}
impl DocEnvironment {
const PRELUDE_ENTRY: &'static str = "prelude-only";
pub fn new(file: Option<PathBuf>) -> Self {
file.map_or(Self::Prelude, Self::Program)
}
fn load(&self, terminal: &mut Terminal) -> Result<SourceId, ExitStatus> {
match self {
Self::Prelude => Ok(terminal.add_empty_source(&self.entry())),
Self::Program(path) => terminal.load(path),
}
}
fn file(&self) -> ProgramFile {
ProgramFile::beside_itself(self.entry())
}
fn entry(&self) -> PathBuf {
match self {
Self::Prelude => PathBuf::from(Self::PRELUDE_ENTRY).with_extension(Language::EXTENSION),
Self::Program(path) => path.clone(),
}
}
}
#[cfg(test)]
mod tests {
use super::{DocOutput, PageText};
use crate::cli::exit_status::ExitStatus;
use crate::cli::token_colors::TokenColors;
#[test]
fn the_type_line_and_the_header_take_the_token_colors_and_the_body_stays_plain() {
let output = DocOutput {
type_line: Some("(type x :k)".to_string()),
page: PageText {
header: "(defn x (:k))".to_string(),
body: "\n\nTakes :k 2.".to_string(),
},
status: ExitStatus::Success,
};
let colors = TokenColors::Painted;
assert_eq!(
output.text(colors),
format!(
"{}\n{}\n\nTakes :k 2.\n",
colors.paint("(type x :k)"),
colors.paint("(defn x (:k))")
)
);
}
}