2021-03-08 23:59:39 +02:00

599 lines
19 KiB
Rust

//! This module contains free-standing functions for creating AST fragments out
//! of smaller pieces.
//!
//! Note that all functions here intended to be stupid constructors, which just
//! assemble a finish node from immediate children. If you want to do something
//! smarter than that, it probably doesn't belong in this module.
//!
//! Keep in mind that `from_text` functions should be kept private. The public
//! API should require to assemble every node piecewise. The trick of
//! `parse(format!())` we use internally is an implementation detail -- long
//! term, it will be replaced with direct tree manipulation.
use itertools::Itertools;
use stdx::format_to;
use crate::{ast, AstNode, SourceFile, SyntaxKind, SyntaxNode, SyntaxToken};
pub fn name(text: &str) -> ast::Name {
ast_from_text(&format!("mod {};", text))
}
pub fn name_ref(text: &str) -> ast::NameRef {
ast_from_text(&format!("fn f() {{ {}; }}", text))
}
// FIXME: replace stringly-typed constructor with a family of typed ctors, a-la
// `expr_xxx`.
pub fn ty(text: &str) -> ast::Type {
ast_from_text(&format!("fn f() -> {} {{}}", text))
}
pub fn ty_unit() -> ast::Type {
ty("()")
}
// FIXME: handle types of length == 1
pub fn ty_tuple(types: impl IntoIterator<Item = ast::Type>) -> ast::Type {
let contents = types.into_iter().join(", ");
ty(&format!("({})", contents))
}
// FIXME: handle path to type
pub fn ty_generic(name: ast::NameRef, types: impl IntoIterator<Item = ast::Type>) -> ast::Type {
let contents = types.into_iter().join(", ");
ty(&format!("{}<{}>", name, contents))
}
pub fn ty_ref(target: ast::Type, exclusive: bool) -> ast::Type {
ty(&if exclusive { format!("&mut {}", target) } else { format!("&{}", target) })
}
pub fn assoc_item_list() -> ast::AssocItemList {
ast_from_text("impl C for D {};")
}
pub fn impl_trait(trait_: ast::Path, ty: ast::Path) -> ast::Impl {
ast_from_text(&format!("impl {} for {} {{}}", trait_, ty))
}
pub fn path_segment(name_ref: ast::NameRef) -> ast::PathSegment {
ast_from_text(&format!("use {};", name_ref))
}
pub fn path_segment_self() -> ast::PathSegment {
ast_from_text("use self;")
}
pub fn path_segment_super() -> ast::PathSegment {
ast_from_text("use super;")
}
pub fn path_segment_crate() -> ast::PathSegment {
ast_from_text("use crate;")
}
pub fn path_unqualified(segment: ast::PathSegment) -> ast::Path {
ast_from_text(&format!("use {}", segment))
}
pub fn path_qualified(qual: ast::Path, segment: ast::PathSegment) -> ast::Path {
ast_from_text(&format!("{}::{}", qual, segment))
}
pub fn path_concat(first: ast::Path, second: ast::Path) -> ast::Path {
ast_from_text(&format!("{}::{}", first, second))
}
pub fn path_from_segments(
segments: impl IntoIterator<Item = ast::PathSegment>,
is_abs: bool,
) -> ast::Path {
let segments = segments.into_iter().map(|it| it.syntax().clone()).join("::");
ast_from_text(&if is_abs {
format!("use ::{};", segments)
} else {
format!("use {};", segments)
})
}
pub fn path_from_text(text: &str) -> ast::Path {
ast_from_text(&format!("fn main() {{ let test = {}; }}", text))
}
pub fn glob_use_tree() -> ast::UseTree {
ast_from_text("use *;")
}
pub fn use_tree(
path: ast::Path,
use_tree_list: Option<ast::UseTreeList>,
alias: Option<ast::Rename>,
add_star: bool,
) -> ast::UseTree {
let mut buf = "use ".to_string();
buf += &path.syntax().to_string();
if let Some(use_tree_list) = use_tree_list {
format_to!(buf, "::{}", use_tree_list);
}
if add_star {
buf += "::*";
}
if let Some(alias) = alias {
format_to!(buf, " {}", alias);
}
ast_from_text(&buf)
}
pub fn use_tree_list(use_trees: impl IntoIterator<Item = ast::UseTree>) -> ast::UseTreeList {
let use_trees = use_trees.into_iter().map(|it| it.syntax().clone()).join(", ");
ast_from_text(&format!("use {{{}}};", use_trees))
}
pub fn use_(visibility: Option<ast::Visibility>, use_tree: ast::UseTree) -> ast::Use {
let visibility = match visibility {
None => String::new(),
Some(it) => format!("{} ", it),
};
ast_from_text(&format!("{}use {};", visibility, use_tree))
}
pub fn record_expr_field(name: ast::NameRef, expr: Option<ast::Expr>) -> ast::RecordExprField {
return match expr {
Some(expr) => from_text(&format!("{}: {}", name, expr)),
None => from_text(&name.to_string()),
};
fn from_text(text: &str) -> ast::RecordExprField {
ast_from_text(&format!("fn f() {{ S {{ {}, }} }}", text))
}
}
pub fn record_field(
visibility: Option<ast::Visibility>,
name: ast::Name,
ty: ast::Type,
) -> ast::RecordField {
let visibility = match visibility {
None => String::new(),
Some(it) => format!("{} ", it),
};
ast_from_text(&format!("struct S {{ {}{}: {}, }}", visibility, name, ty))
}
pub fn block_expr(
stmts: impl IntoIterator<Item = ast::Stmt>,
tail_expr: Option<ast::Expr>,
) -> ast::BlockExpr {
let mut buf = "{\n".to_string();
for stmt in stmts.into_iter() {
format_to!(buf, " {}\n", stmt);
}
if let Some(tail_expr) = tail_expr {
format_to!(buf, " {}\n", tail_expr)
}
buf += "}";
ast_from_text(&format!("fn f() {}", buf))
}
pub fn expr_unit() -> ast::Expr {
expr_from_text("()")
}
pub fn expr_empty_block() -> ast::Expr {
expr_from_text("{}")
}
pub fn expr_unimplemented() -> ast::Expr {
expr_from_text("unimplemented!()")
}
pub fn expr_unreachable() -> ast::Expr {
expr_from_text("unreachable!()")
}
pub fn expr_todo() -> ast::Expr {
expr_from_text("todo!()")
}
pub fn expr_path(path: ast::Path) -> ast::Expr {
expr_from_text(&path.to_string())
}
pub fn expr_continue() -> ast::Expr {
expr_from_text("continue")
}
pub fn expr_break(expr: Option<ast::Expr>) -> ast::Expr {
match expr {
Some(expr) => expr_from_text(&format!("break {}", expr)),
None => expr_from_text("break"),
}
}
pub fn expr_return(expr: Option<ast::Expr>) -> ast::Expr {
match expr {
Some(expr) => expr_from_text(&format!("return {}", expr)),
None => expr_from_text("return"),
}
}
pub fn expr_try(expr: ast::Expr) -> ast::Expr {
expr_from_text(&format!("{}?", expr))
}
pub fn expr_match(expr: ast::Expr, match_arm_list: ast::MatchArmList) -> ast::Expr {
expr_from_text(&format!("match {} {}", expr, match_arm_list))
}
pub fn expr_if(
condition: ast::Condition,
then_branch: ast::BlockExpr,
else_branch: Option<ast::ElseBranch>,
) -> ast::Expr {
let else_branch = match else_branch {
Some(ast::ElseBranch::Block(block)) => format!("else {}", block),
Some(ast::ElseBranch::IfExpr(if_expr)) => format!("else {}", if_expr),
None => String::new(),
};
expr_from_text(&format!("if {} {} {}", condition, then_branch, else_branch))
}
pub fn expr_prefix(op: SyntaxKind, expr: ast::Expr) -> ast::Expr {
let token = token(op);
expr_from_text(&format!("{}{}", token, expr))
}
pub fn expr_call(f: ast::Expr, arg_list: ast::ArgList) -> ast::Expr {
expr_from_text(&format!("{}{}", f, arg_list))
}
pub fn expr_method_call(receiver: ast::Expr, method: &str, arg_list: ast::ArgList) -> ast::Expr {
expr_from_text(&format!("{}.{}{}", receiver, method, arg_list))
}
pub fn expr_ref(expr: ast::Expr, exclusive: bool) -> ast::Expr {
expr_from_text(&if exclusive { format!("&mut {}", expr) } else { format!("&{}", expr) })
}
pub fn expr_paren(expr: ast::Expr) -> ast::Expr {
expr_from_text(&format!("({})", expr))
}
pub fn expr_tuple(elements: impl IntoIterator<Item = ast::Expr>) -> ast::Expr {
let expr = elements.into_iter().format(", ");
expr_from_text(&format!("({})", expr))
}
fn expr_from_text(text: &str) -> ast::Expr {
ast_from_text(&format!("const C: () = {};", text))
}
pub fn condition(expr: ast::Expr, pattern: Option<ast::Pat>) -> ast::Condition {
match pattern {
None => ast_from_text(&format!("const _: () = while {} {{}};", expr)),
Some(pattern) => {
ast_from_text(&format!("const _: () = while let {} = {} {{}};", pattern, expr))
}
}
}
pub fn arg_list(args: impl IntoIterator<Item = ast::Expr>) -> ast::ArgList {
ast_from_text(&format!("fn main() {{ ()({}) }}", args.into_iter().format(", ")))
}
pub fn ident_pat(name: ast::Name) -> ast::IdentPat {
return from_text(name.text());
fn from_text(text: &str) -> ast::IdentPat {
ast_from_text(&format!("fn f({}: ())", text))
}
}
pub fn ident_mut_pat(name: ast::Name) -> ast::IdentPat {
return from_text(name.text());
fn from_text(text: &str) -> ast::IdentPat {
ast_from_text(&format!("fn f(mut {}: ())", text))
}
}
pub fn wildcard_pat() -> ast::WildcardPat {
return from_text("_");
fn from_text(text: &str) -> ast::WildcardPat {
ast_from_text(&format!("fn f({}: ())", text))
}
}
/// Creates a tuple of patterns from an iterator of patterns.
///
/// Invariant: `pats` must be length > 1
///
/// FIXME handle `pats` length == 1
pub fn tuple_pat(pats: impl IntoIterator<Item = ast::Pat>) -> ast::TuplePat {
let pats_str = pats.into_iter().map(|p| p.to_string()).join(", ");
return from_text(&format!("({})", pats_str));
fn from_text(text: &str) -> ast::TuplePat {
ast_from_text(&format!("fn f({}: ())", text))
}
}
pub fn tuple_struct_pat(
path: ast::Path,
pats: impl IntoIterator<Item = ast::Pat>,
) -> ast::TupleStructPat {
let pats_str = pats.into_iter().join(", ");
return from_text(&format!("{}({})", path, pats_str));
fn from_text(text: &str) -> ast::TupleStructPat {
ast_from_text(&format!("fn f({}: ())", text))
}
}
pub fn record_pat(path: ast::Path, pats: impl IntoIterator<Item = ast::Pat>) -> ast::RecordPat {
let pats_str = pats.into_iter().join(", ");
return from_text(&format!("{} {{ {} }}", path, pats_str));
fn from_text(text: &str) -> ast::RecordPat {
ast_from_text(&format!("fn f({}: ())", text))
}
}
/// Returns a `BindPat` if the path has just one segment, a `PathPat` otherwise.
pub fn path_pat(path: ast::Path) -> ast::Pat {
return from_text(&path.to_string());
fn from_text(text: &str) -> ast::Pat {
ast_from_text(&format!("fn f({}: ())", text))
}
}
pub fn match_arm(pats: impl IntoIterator<Item = ast::Pat>, expr: ast::Expr) -> ast::MatchArm {
let pats_str = pats.into_iter().join(" | ");
return from_text(&format!("{} => {}", pats_str, expr));
fn from_text(text: &str) -> ast::MatchArm {
ast_from_text(&format!("fn f() {{ match () {{{}}} }}", text))
}
}
pub fn match_arm_list(arms: impl IntoIterator<Item = ast::MatchArm>) -> ast::MatchArmList {
let arms_str = arms
.into_iter()
.map(|arm| {
let needs_comma = arm.expr().map_or(true, |it| !it.is_block_like());
let comma = if needs_comma { "," } else { "" };
format!(" {}{}\n", arm.syntax(), comma)
})
.collect::<String>();
return from_text(&arms_str);
fn from_text(text: &str) -> ast::MatchArmList {
ast_from_text(&format!("fn f() {{ match () {{\n{}}} }}", text))
}
}
pub fn where_pred(
path: ast::Path,
bounds: impl IntoIterator<Item = ast::TypeBound>,
) -> ast::WherePred {
let bounds = bounds.into_iter().join(" + ");
return from_text(&format!("{}: {}", path, bounds));
fn from_text(text: &str) -> ast::WherePred {
ast_from_text(&format!("fn f() where {} {{ }}", text))
}
}
pub fn where_clause(preds: impl IntoIterator<Item = ast::WherePred>) -> ast::WhereClause {
let preds = preds.into_iter().join(", ");
return from_text(preds.as_str());
fn from_text(text: &str) -> ast::WhereClause {
ast_from_text(&format!("fn f() where {} {{ }}", text))
}
}
pub fn let_stmt(pattern: ast::Pat, initializer: Option<ast::Expr>) -> ast::LetStmt {
let text = match initializer {
Some(it) => format!("let {} = {};", pattern, it),
None => format!("let {};", pattern),
};
ast_from_text(&format!("fn f() {{ {} }}", text))
}
pub fn expr_stmt(expr: ast::Expr) -> ast::ExprStmt {
let semi = if expr.is_block_like() { "" } else { ";" };
ast_from_text(&format!("fn f() {{ {}{} (); }}", expr, semi))
}
pub fn token(kind: SyntaxKind) -> SyntaxToken {
tokens::SOURCE_FILE
.tree()
.syntax()
.descendants_with_tokens()
.filter_map(|it| it.into_token())
.find(|it| it.kind() == kind)
.unwrap_or_else(|| panic!("unhandled token: {:?}", kind))
}
pub fn param(pat: ast::Pat, ty: ast::Type) -> ast::Param {
ast_from_text(&format!("fn f({}: {}) {{ }}", pat, ty))
}
pub fn ret_type(ty: ast::Type) -> ast::RetType {
ast_from_text(&format!("fn f() -> {} {{ }}", ty))
}
pub fn param_list(
self_param: Option<ast::SelfParam>,
pats: impl IntoIterator<Item = ast::Param>,
) -> ast::ParamList {
let args = pats.into_iter().join(", ");
let list = match self_param {
Some(self_param) if args.is_empty() => format!("fn f({}) {{ }}", self_param),
Some(self_param) => format!("fn f({}, {}) {{ }}", self_param, args),
None => format!("fn f({}) {{ }}", args),
};
ast_from_text(&list)
}
pub fn generic_param(name: String, ty: Option<ast::TypeBoundList>) -> ast::GenericParam {
let bound = match ty {
Some(it) => format!(": {}", it),
None => String::new(),
};
ast_from_text(&format!("fn f<{}{}>() {{ }}", name, bound))
}
pub fn generic_param_list(
pats: impl IntoIterator<Item = ast::GenericParam>,
) -> ast::GenericParamList {
let args = pats.into_iter().join(", ");
ast_from_text(&format!("fn f<{}>() {{ }}", args))
}
pub fn visibility_pub_crate() -> ast::Visibility {
ast_from_text("pub(crate) struct S")
}
pub fn visibility_pub() -> ast::Visibility {
ast_from_text("pub struct S")
}
pub fn tuple_field_list(fields: impl IntoIterator<Item = ast::TupleField>) -> ast::TupleFieldList {
let fields = fields.into_iter().join(", ");
ast_from_text(&format!("struct f({});", fields))
}
pub fn record_field_list(
fields: impl IntoIterator<Item = ast::RecordField>,
) -> ast::RecordFieldList {
let fields = fields.into_iter().join(", ");
ast_from_text(&format!("struct f {{ {} }}", fields))
}
pub fn tuple_field(visibility: Option<ast::Visibility>, ty: ast::Type) -> ast::TupleField {
let visibility = match visibility {
None => String::new(),
Some(it) => format!("{} ", it),
};
ast_from_text(&format!("struct f({}{});", visibility, ty))
}
pub fn variant(name: ast::Name, field_list: Option<ast::FieldList>) -> ast::Variant {
let field_list = match field_list {
None => String::new(),
Some(it) => format!("{}", it),
};
ast_from_text(&format!("enum f {{ {}{} }}", name, field_list))
}
pub fn fn_(
visibility: Option<ast::Visibility>,
fn_name: ast::Name,
type_params: Option<ast::GenericParamList>,
params: ast::ParamList,
body: ast::BlockExpr,
ret_type: Option<ast::RetType>,
) -> ast::Fn {
let type_params =
if let Some(type_params) = type_params { format!("<{}>", type_params) } else { "".into() };
let ret_type = if let Some(ret_type) = ret_type { format!("{} ", ret_type) } else { "".into() };
let visibility = match visibility {
None => String::new(),
Some(it) => format!("{} ", it),
};
ast_from_text(&format!(
"{}fn {}{}{} {}{}",
visibility, fn_name, type_params, params, ret_type, body
))
}
pub fn struct_(
visibility: Option<ast::Visibility>,
strukt_name: ast::Name,
type_params: Option<ast::GenericParamList>,
field_list: ast::FieldList,
) -> ast::Struct {
let semicolon = if matches!(field_list, ast::FieldList::TupleFieldList(_)) { ";" } else { "" };
let type_params =
if let Some(type_params) = type_params { format!("<{}>", type_params) } else { "".into() };
let visibility = match visibility {
None => String::new(),
Some(it) => format!("{} ", it),
};
ast_from_text(&format!(
"{}struct {}{}{}{}",
visibility, strukt_name, type_params, field_list, semicolon
))
}
fn ast_from_text<N: AstNode>(text: &str) -> N {
let parse = SourceFile::parse(text);
let node = match parse.tree().syntax().descendants().find_map(N::cast) {
Some(it) => it,
None => {
panic!("Failed to make ast node `{}` from text {}", std::any::type_name::<N>(), text)
}
};
let node = node.syntax().clone();
let node = unroot(node);
let node = N::cast(node).unwrap();
assert_eq!(node.syntax().text_range().start(), 0.into());
node
}
fn unroot(n: SyntaxNode) -> SyntaxNode {
SyntaxNode::new_root(n.green().to_owned())
}
pub mod tokens {
use once_cell::sync::Lazy;
use crate::{ast, AstNode, Parse, SourceFile, SyntaxKind::*, SyntaxToken};
pub(super) static SOURCE_FILE: Lazy<Parse<SourceFile>> = Lazy::new(|| {
SourceFile::parse(
"const C: <()>::Item = (1 != 1, 2 == 2, 3 < 3, 4 <= 4, 5 > 5, 6 >= 6, !true, *p)\n;\n\n",
)
});
pub fn single_space() -> SyntaxToken {
SOURCE_FILE
.tree()
.syntax()
.descendants_with_tokens()
.filter_map(|it| it.into_token())
.find(|it| it.kind() == WHITESPACE && it.text() == " ")
.unwrap()
}
pub fn whitespace(text: &str) -> SyntaxToken {
assert!(text.trim().is_empty());
let sf = SourceFile::parse(text).ok().unwrap();
sf.syntax().first_child_or_token().unwrap().into_token().unwrap()
}
pub fn doc_comment(text: &str) -> SyntaxToken {
assert!(!text.trim().is_empty());
let sf = SourceFile::parse(text).ok().unwrap();
sf.syntax().first_child_or_token().unwrap().into_token().unwrap()
}
pub fn literal(text: &str) -> SyntaxToken {
assert_eq!(text.trim(), text);
let lit: ast::Literal = super::ast_from_text(&format!("fn f() {{ let _ = {}; }}", text));
lit.syntax().first_child_or_token().unwrap().into_token().unwrap()
}
pub fn single_newline() -> SyntaxToken {
SOURCE_FILE
.tree()
.syntax()
.descendants_with_tokens()
.filter_map(|it| it.into_token())
.find(|it| it.kind() == WHITESPACE && it.text() == "\n")
.unwrap()
}
pub fn blank_line() -> SyntaxToken {
SOURCE_FILE
.tree()
.syntax()
.descendants_with_tokens()
.filter_map(|it| it.into_token())
.find(|it| it.kind() == WHITESPACE && it.text() == "\n\n")
.unwrap()
}
pub struct WsBuilder(SourceFile);
impl WsBuilder {
pub fn new(text: &str) -> WsBuilder {
WsBuilder(SourceFile::parse(text).ok().unwrap())
}
pub fn ws(&self) -> SyntaxToken {
self.0.syntax().first_child_or_token().unwrap().into_token().unwrap()
}
}
}