Files
simple-rust-tests/__wasm/wit-bindgen-sample/wit-bindgen/crates/gen-wasmtime-py/src/source.rs

502 lines
16 KiB
Rust

use heck::*;
use wit_bindgen_gen_core::wit_parser::*;
use crate::dependencies::Dependencies;
/// A [Source] represents some unit of Python code
/// and keeps track of its indent.
#[derive(Default)]
pub struct Source {
s: String,
indent: usize,
}
impl Source {
/// Appends a string slice to this [Source].
///
/// Strings without newlines, they are simply appended.
/// Strings with newlines are appended and also new lines
/// are indented based on the current indent level.
pub fn push_str(&mut self, src: &str) {
let lines = src.lines().collect::<Vec<_>>();
let mut trim = None;
for (i, line) in lines.iter().enumerate() {
self.s.push_str(if lines.len() == 1 {
line
} else {
let trim = match trim {
Some(n) => n,
None => {
let val = line.len() - line.trim_start().len();
if !line.is_empty() {
trim = Some(val);
}
val
}
};
line.get(trim..).unwrap_or("")
});
if i != lines.len() - 1 || src.ends_with("\n") {
self.newline();
}
}
}
/// Prints the documentation as comments
/// e.g.
/// > \# Line one of docs node
/// >
/// > \# Line two of docs node
pub fn comment(&mut self, docs: &Docs) {
let docs = match &docs.contents {
Some(docs) => docs,
None => return,
};
for line in docs.lines() {
self.push_str(&format!("# {}\n", line));
}
}
/// Prints the documentation as comments
/// e.g.
/// > """
/// >
/// > Line one of docs node
/// >
/// > Line two of docs node
/// >
/// > """
pub fn docstring(&mut self, docs: &Docs) {
let docs = match &docs.contents {
Some(docs) => docs,
None => return,
};
let triple_quote = r#"""""#;
self.push_str(triple_quote);
self.newline();
for line in docs.lines() {
self.push_str(line);
self.newline();
}
self.push_str(triple_quote);
self.newline();
}
/// Indent the source one level.
pub fn indent(&mut self) {
self.indent += 4;
self.s.push_str(" ");
}
/// Unindent, or in Python terms "dedent",
/// the source one level.
pub fn dedent(&mut self) {
self.indent -= 4;
assert!(self.s.ends_with(" "));
self.s.pop();
self.s.pop();
self.s.pop();
self.s.pop();
}
/// Go to the next line and apply any indent.
pub fn newline(&mut self) {
self.s.push_str("\n");
for _ in 0..self.indent {
self.s.push_str(" ");
}
}
}
impl std::ops::Deref for Source {
type Target = str;
fn deref(&self) -> &str {
&self.s
}
}
impl From<Source> for String {
fn from(s: Source) -> String {
s.s
}
}
/// [SourceBuilder] combines together a [Source]
/// with other contextual information and state.
///
/// This allows you to generate code for the Source using
/// high-level tools that take care of updating dependencies
/// and retrieving interface details.
///
/// You can create a [SourceBuilder] easily using a [Source]
/// ```
/// # use wit_bindgen_gen_wasmtime_py::dependencies::Dependencies;
/// # use wit_bindgen_gen_core::wit_parser::{Interface, Type};
/// # use wit_bindgen_gen_wasmtime_py::source::Source;
/// # let mut deps = Dependencies::default();
/// # let mut interface = Interface::default();
/// # let iface = &interface;
/// let mut source = Source::default();
/// let mut builder = source.builder(&mut deps, iface);
/// builder.print_ty(&Type::Bool, false);
/// ```
pub struct SourceBuilder<'s, 'd, 'i> {
source: &'s mut Source,
pub deps: &'d mut Dependencies,
iface: &'i Interface,
}
impl<'s, 'd, 'i> Source {
/// Create a [SourceBuilder] for the current source.
pub fn builder(
&'s mut self,
deps: &'d mut Dependencies,
iface: &'i Interface,
) -> SourceBuilder<'s, 'd, 'i> {
SourceBuilder {
source: self,
deps,
iface,
}
}
}
impl<'s, 'd, 'i> SourceBuilder<'s, 'd, 'i> {
/// See [Dependencies::pyimport].
pub fn pyimport<'a>(&mut self, module: &str, name: impl Into<Option<&'a str>>) {
self.deps.pyimport(module, name)
}
/// Appends a type's Python representation to this `Source`.
/// Records any required intrinsics and imports in the `deps`.
/// Uses Python forward reference syntax (e.g. 'Foo')
/// on the root type only if `forward_ref` is true.
pub fn print_ty(&mut self, ty: &Type, forward_ref: bool) {
match ty {
Type::Unit => self.push_str("None"),
Type::Bool => self.push_str("bool"),
Type::U8
| Type::S8
| Type::U16
| Type::S16
| Type::U32
| Type::S32
| Type::U64
| Type::S64 => self.push_str("int"),
Type::Float32 | Type::Float64 => self.push_str("float"),
Type::Char => self.push_str("str"),
Type::String => self.push_str("str"),
Type::Handle(id) => {
if forward_ref {
self.push_str("'");
}
let handle_name = &self.iface.resources[*id].name.to_camel_case();
self.source.push_str(handle_name);
if forward_ref {
self.push_str("'");
}
}
Type::Id(id) => {
let ty = &self.iface.types[*id];
if let Some(name) = &ty.name {
self.push_str(&name.to_camel_case());
return;
}
match &ty.kind {
TypeDefKind::Type(t) => self.print_ty(t, forward_ref),
TypeDefKind::Tuple(t) => self.print_tuple(t),
TypeDefKind::Record(_)
| TypeDefKind::Flags(_)
| TypeDefKind::Enum(_)
| TypeDefKind::Variant(_)
| TypeDefKind::Union(_) => {
unreachable!()
}
TypeDefKind::Option(t) => {
self.deps.pyimport("typing", "Optional");
self.push_str("Optional[");
self.print_ty(t, true);
self.push_str("]");
}
TypeDefKind::Expected(e) => {
self.deps.needs_expected = true;
self.push_str("Expected[");
self.print_ty(&e.ok, true);
self.push_str(", ");
self.print_ty(&e.err, true);
self.push_str("]");
}
TypeDefKind::List(t) => self.print_list(t),
TypeDefKind::Future(t) => {
self.push_str("Future[");
self.print_ty(t, true);
self.push_str("]");
}
TypeDefKind::Stream(s) => {
self.push_str("Stream[");
self.print_ty(&s.element, true);
self.push_str(", ");
self.print_ty(&s.end, true);
self.push_str("]");
}
}
}
}
}
/// Appends a tuple type's Python representation to this `Source`.
/// Records any required intrinsics and imports in the `deps`.
/// Uses Python forward reference syntax (e.g. 'Foo') for named type parameters.
pub fn print_tuple(&mut self, tuple: &Tuple) {
if tuple.types.is_empty() {
return self.push_str("None");
}
self.deps.pyimport("typing", "Tuple");
self.push_str("Tuple[");
for (i, t) in tuple.types.iter().enumerate() {
if i > 0 {
self.push_str(", ");
}
self.print_ty(t, true);
}
self.push_str("]");
}
/// Appends a Python type representing a sequence of the `element` type to this `Source`.
/// If the element type is `Type::U8`, the result type is `bytes` otherwise it is a `List[T]`
/// Records any required intrinsics and imports in the `deps`.
/// Uses Python forward reference syntax (e.g. 'Foo') for named type parameters.
pub fn print_list(&mut self, element: &Type) {
match element {
Type::U8 => self.push_str("bytes"),
t => {
self.deps.pyimport("typing", "List");
self.push_str("List[");
self.print_ty(t, true);
self.push_str("]");
}
}
}
/// Print variable declaration.
/// Brings name into scope and binds type to it.
pub fn print_var_declaration<'a>(&mut self, name: &'a str, ty: &Type) {
self.push_str(name);
self.push_str(": ");
self.print_ty(ty, true);
self.push_str("\n");
}
pub fn print_sig(&mut self, func: &Function, in_import: bool) -> Vec<String> {
if !in_import {
if let FunctionKind::Static { .. } = func.kind {
self.push_str("@classmethod\n");
}
}
self.source.push_str("def ");
match &func.kind {
FunctionKind::Method { .. } => self.source.push_str(&func.item_name().to_snake_case()),
FunctionKind::Static { .. } if !in_import => {
self.source.push_str(&func.item_name().to_snake_case())
}
_ => self.source.push_str(&func.name.to_snake_case()),
}
if in_import {
self.source.push_str("(self");
} else if let FunctionKind::Static { .. } = func.kind {
self.source.push_str("(cls, caller: wasmtime.Store, obj: '");
self.source.push_str(&self.iface.name.to_camel_case());
self.source.push_str("'");
} else {
self.source.push_str("(self, caller: wasmtime.Store");
}
let mut params = Vec::new();
for (i, (param, ty)) in func.params.iter().enumerate() {
if i == 0 {
if let FunctionKind::Method { .. } = func.kind {
params.push("self".to_string());
continue;
}
}
self.source.push_str(", ");
self.source.push_str(&param.to_snake_case());
params.push(param.to_snake_case());
self.source.push_str(": ");
self.print_ty(ty, true);
}
self.source.push_str(") -> ");
self.print_ty(&func.result, true);
params
}
/// Print a wrapped union definition.
/// e.g.
/// ```py
/// @dataclass
/// class Foo0:
/// value: int
///
/// @dataclass
/// class Foo1:
/// value: int
///
/// Foo = Union[Foo0, Foo1]
/// ```
pub fn print_union_wrapped(&mut self, name: &str, union: &Union, docs: &Docs) {
self.deps.pyimport("dataclasses", "dataclass");
let mut cases = Vec::new();
let name = name.to_camel_case();
for (i, case) in union.cases.iter().enumerate() {
self.source.push_str("@dataclass\n");
let name = format!("{name}{i}");
self.source.push_str(&format!("class {name}:\n"));
self.source.indent();
self.source.docstring(&case.docs);
self.source.push_str("value: ");
self.print_ty(&case.ty, true);
self.source.newline();
self.source.dedent();
self.source.newline();
cases.push(name);
}
self.deps.pyimport("typing", "Union");
self.source.comment(docs);
self.source
.push_str(&format!("{name} = Union[{}]\n", cases.join(", ")));
self.source.newline();
}
pub fn print_union_raw(&mut self, name: &str, union: &Union, docs: &Docs) {
self.deps.pyimport("typing", "Union");
self.source.comment(docs);
for case in union.cases.iter() {
self.source.comment(&case.docs);
}
self.source.push_str(&name.to_camel_case());
self.source.push_str(" = Union[");
let mut first = true;
for case in union.cases.iter() {
if !first {
self.source.push_str(",");
}
self.print_ty(&case.ty, true);
first = false;
}
self.source.push_str("]\n\n");
}
}
impl<'s, 'd, 'i> std::ops::Deref for SourceBuilder<'s, 'd, 'i> {
type Target = Source;
fn deref(&self) -> &Source {
&self.source
}
}
impl<'s, 'd, 'i> std::ops::DerefMut for SourceBuilder<'s, 'd, 'i> {
fn deref_mut(&mut self) -> &mut Source {
&mut self.source
}
}
#[cfg(test)]
mod tests {
use std::collections::{BTreeMap, BTreeSet};
use super::*;
#[test]
fn simple_append() {
let mut s = Source::default();
s.push_str("x");
assert_eq!(s.s, "x");
s.push_str("y");
assert_eq!(s.s, "xy");
s.push_str("z ");
assert_eq!(s.s, "xyz ");
s.push_str(" a ");
assert_eq!(s.s, "xyz a ");
s.push_str("\na");
assert_eq!(s.s, "xyz a \na");
}
#[test]
fn trim_ws() {
let mut s = Source::default();
s.push_str("def foo():\n return 1\n");
assert_eq!(s.s, "def foo():\n return 1\n");
}
#[test]
fn print_ty_forward_ref() {
let mut deps = Dependencies::default();
let mut iface = Interface::default();
// Set up a Resource type to refer to
let resource_id = iface.resources.alloc(Resource {
docs: Docs::default(),
name: "foo".into(),
supertype: None,
foreign_module: None,
});
iface.resource_lookup.insert("foo".into(), resource_id);
let handle_ty = Type::Handle(resource_id);
// ForwardRef usage can be controlled by an argument to print_ty
let mut s1 = Source::default();
let mut builder = s1.builder(&mut deps, &iface);
builder.print_ty(&handle_ty, true);
drop(builder);
assert_eq!(s1.s, "'Foo'");
let mut s2 = Source::default();
let mut builder = s2.builder(&mut deps, &iface);
builder.print_ty(&handle_ty, false);
drop(builder);
assert_eq!(s2.s, "Foo");
// ForwardRef is used for any types within other types
// Even if the outer type is itself not allowed to be one
let option_id = iface.types.alloc(TypeDef {
docs: Docs::default(),
kind: TypeDefKind::Option(handle_ty),
name: None,
foreign_module: None,
});
let option_ty = Type::Id(option_id);
let mut s3 = Source::default();
let mut builder = s3.builder(&mut deps, &iface);
builder.print_ty(&option_ty, false);
drop(builder);
assert_eq!(s3.s, "Optional['Foo']");
}
#[test]
fn print_list_bytes() {
// If the element type is u8, it is interpreted as `bytes`
let mut deps = Dependencies::default();
let iface = Interface::default();
let mut source = Source::default();
let mut builder = source.builder(&mut deps, &iface);
builder.print_list(&Type::U8);
drop(builder);
assert_eq!(source.s, "bytes");
assert_eq!(deps.pyimports, BTreeMap::default());
}
#[test]
fn print_list_non_bytes() {
// If the element type is u8, it is interpreted as `bytes`
let mut deps = Dependencies::default();
let iface = Interface::default();
let mut source = Source::default();
let mut builder = source.builder(&mut deps, &iface);
builder.print_list(&Type::Float32);
drop(builder);
assert_eq!(source.s, "List[float]");
assert_eq!(
deps.pyimports,
BTreeMap::from([("typing".into(), Some(BTreeSet::from(["List".into()])))])
);
}
}