use std::fmt::{self, Display}; use join_to_string::join; use ra_syntax::ast::{self, AstNode, NameOwner, VisibilityOwner}; use std::convert::From; use hir::{Docs, Documentation, HasSource}; use crate::{db, display::{where_predicates, generic_parameters}}; /// Contains information about a function signature #[derive(Debug)] pub struct FunctionSignature { /// Optional visibility pub visibility: Option, /// Name of the function pub name: Option, /// Documentation for the function pub doc: Option, /// Generic parameters pub generic_parameters: Vec, /// Parameters of the function pub parameters: Vec, /// Optional return type pub ret_type: Option, /// Where predicates pub where_predicates: Vec, } impl FunctionSignature { pub(crate) fn with_doc_opt(mut self, doc: Option) -> Self { self.doc = doc; self } pub(crate) fn from_hir(db: &db::RootDatabase, function: hir::Function) -> Self { let doc = function.docs(db); let ast_node = function.source(db).ast; FunctionSignature::from(&*ast_node).with_doc_opt(doc) } } impl From<&'_ ast::FnDef> for FunctionSignature { fn from(node: &ast::FnDef) -> FunctionSignature { fn param_list(node: &ast::FnDef) -> Vec { let mut res = vec![]; if let Some(param_list) = node.param_list() { if let Some(self_param) = param_list.self_param() { res.push(self_param.syntax().text().to_string()) } res.extend(param_list.params().map(|param| param.syntax().text().to_string())); } res } FunctionSignature { visibility: node.visibility().map(|n| n.syntax().text().to_string()), name: node.name().map(|n| n.text().to_string()), ret_type: node .ret_type() .and_then(|r| r.type_ref()) .map(|n| n.syntax().text().to_string()), parameters: param_list(node), generic_parameters: generic_parameters(node), where_predicates: where_predicates(node), // docs are processed separately doc: None, } } } impl Display for FunctionSignature { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { if let Some(t) = &self.visibility { write!(f, "{} ", t)?; } if let Some(name) = &self.name { write!(f, "fn {}", name)?; } if !self.generic_parameters.is_empty() { join(self.generic_parameters.iter()) .separator(", ") .surround_with("<", ">") .to_fmt(f)?; } join(self.parameters.iter()).separator(", ").surround_with("(", ")").to_fmt(f)?; if let Some(t) = &self.ret_type { write!(f, " -> {}", t)?; } if !self.where_predicates.is_empty() { write!(f, "\nwhere ")?; join(self.where_predicates.iter()).separator(",\n ").to_fmt(f)?; } Ok(()) } }