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//! This module contains free-standing functions for creating AST fragments out
//! of smaller pieces.
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))
}
pub fn path_segment(name_ref: ast::NameRef) -> ast::PathSegment {
ast_from_text(&format!("use {};", name_ref))
}
pub fn path_unqualified(segment: ast::PathSegment) -> ast::Path {
path_from_text(&format!("use {}", segment))
}
pub fn path_qualified(qual: ast::Path, segment: ast::PathSegment) -> ast::Path {
path_from_text(&format!("{}::{}", qual, segment))
}
fn path_from_text(text: &str) -> ast::Path {
ast_from_text(text)
}
pub fn use_tree(
path: ast::Path,
use_tree_list: Option<ast::UseTreeList>,
alias: Option<ast::Alias>,
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_item(use_tree: ast::UseTree) -> ast::UseItem {
ast_from_text(&format!("use {};", use_tree))
}
pub fn record_field(name: ast::NameRef, expr: Option<ast::Expr>) -> ast::RecordField {
return match expr {
Some(expr) => from_text(&format!("{}: {}", name, expr)),
None => from_text(&name.to_string()),
};
fn from_text(text: &str) -> ast::RecordField {
ast_from_text(&format!("fn f() {{ S {{ {}, }} }}", text))
}
}
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 block_from_expr(e: ast::Expr) -> ast::BlockExpr {
return from_text(&format!("{{ {} }}", e));
fn from_text(text: &str) -> ast::BlockExpr {
ast_from_text(&format!("fn f() {}", text))
}
}
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_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() -> ast::Expr {
expr_from_text("break")
}
pub fn expr_return() -> ast::Expr {
expr_from_text("return")
}
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) -> ast::Expr {
expr_from_text(&format!("if {} {}", condition, then_branch))
}
pub fn expr_prefix(op: SyntaxKind, expr: ast::Expr) -> ast::Expr {
let token = token(op);
expr_from_text(&format!("{}{}", token, expr))
}
fn expr_from_text(text: &str) -> ast::Expr {
ast_from_text(&format!("const C: () = {};", text))
}
pub fn try_expr_from_text(text: &str) -> Option<ast::Expr> {
try_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 bind_pat(name: ast::Name) -> ast::BindPat {
return from_text(name.text());
fn from_text(text: &str) -> ast::BindPat {
ast_from_text(&format!("fn f({}: ())", text))
}
}
pub fn placeholder_pat() -> ast::PlaceholderPat {
return from_text("_");
fn from_text(text: &str) -> ast::PlaceholderPat {
ast_from_text(&format!("fn f({}: ())", text))
}
}
/// Creates a tuple of patterns from an interator 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 unreachable_macro_call() -> ast::MacroCall {
ast_from_text(&format!("unreachable!()"))
}
pub fn param(name: String, ty: String) -> ast::Param {
ast_from_text(&format!("fn f({}: {}) {{ }}", name, ty))
}
pub fn param_list(pats: impl IntoIterator<Item = ast::Param>) -> ast::ParamList {
let args = pats.into_iter().join(", ");
ast_from_text(&format!("fn f({}) {{ }}", args))
}
pub fn fn_def(
fn_name: ast::Name,
type_params: Option<ast::TypeParamList>,
params: ast::ParamList,
body: ast::BlockExpr,
) -> ast::FnDef {
let type_params =
if let Some(type_params) = type_params { format!("<{}>", type_params) } else { "".into() };
ast_from_text(&format!("fn {}{}{} {}", fn_name, type_params, params, body))
}
pub fn add_leading_newlines(amount_of_newlines: usize, t: impl AstNode) -> ast::SourceFile {
let newlines = "\n".repeat(amount_of_newlines);
ast_from_text(&format!("{}{}", newlines, t.syntax()))
}
pub fn add_trailing_newlines(amount_of_newlines: usize, t: impl AstNode) -> ast::SourceFile {
let newlines = "\n".repeat(amount_of_newlines);
ast_from_text(&format!("{}{}", t.syntax(), newlines))
}
pub fn add_pub_crate_modifier(fn_def: ast::FnDef) -> ast::FnDef {
ast_from_text(&format!("pub(crate) {}", fn_def))
}
fn ast_from_text<N: AstNode>(text: &str) -> N {
let parse = SourceFile::parse(text);
let node = parse.tree().syntax().descendants().find_map(N::cast).unwrap();
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 try_ast_from_text<N: AstNode>(text: &str) -> Option<N> {
let parse = SourceFile::parse(text);
let node = parse.tree().syntax().descendants().find_map(N::cast)?;
let node = node.syntax().clone();
let node = unroot(node);
let node = N::cast(node).unwrap();
assert_eq!(node.syntax().text_range().start(), 0.into());
Some(node)
}
fn unroot(n: SyntaxNode) -> SyntaxNode {
SyntaxNode::new_root(n.green().clone())
}
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, !true)\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().as_str() == " ")
.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().as_str() == "\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()
}
}
}
|