1 files changed, 252 insertions, 0 deletions

diff --git a/crates/ra_syntax/src/ast/expr_extensions.rs b/crates/ra_syntax/src/ast/expr_extensions.rs
new file mode 100644
index 000000000..1d8313810
--- /dev/null
+++ b/crates/ra_syntax/src/ast/expr_extensions.rs
@@ -0,0 +1,252 @@
+//! Various extension methods to ast Expr Nodes, which are hard to code-generate.
+
+use crate::{
+    SyntaxToken, SyntaxElement, SmolStr,
+    ast::{self, AstNode, AstChildren, children, child_opt},
+    SyntaxKind::*
+};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ElseBranch<'a> {
+    Block(&'a ast::Block),
+    IfExpr(&'a ast::IfExpr),
+}
+
+impl ast::IfExpr {
+    pub fn then_branch(&self) -> Option<&ast::Block> {
+        self.blocks().nth(0)
+    }
+    pub fn else_branch(&self) -> Option<ElseBranch> {
+        let res = match self.blocks().nth(1) {
+            Some(block) => ElseBranch::Block(block),
+            None => {
+                let elif: &ast::IfExpr = child_opt(self)?;
+                ElseBranch::IfExpr(elif)
+            }
+        };
+        Some(res)
+    }
+
+    fn blocks(&self) -> AstChildren<ast::Block> {
+        children(self)
+    }
+}
+
+impl ast::RefExpr {
+    pub fn is_mut(&self) -> bool {
+        self.syntax().children_with_tokens().any(|n| n.kind() == MUT_KW)
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub enum PrefixOp {
+    /// The `*` operator for dereferencing
+    Deref,
+    /// The `!` operator for logical inversion
+    Not,
+    /// The `-` operator for negation
+    Neg,
+}
+
+impl ast::PrefixExpr {
+    pub fn op_kind(&self) -> Option<PrefixOp> {
+        match self.op_token()?.kind() {
+            STAR => Some(PrefixOp::Deref),
+            EXCL => Some(PrefixOp::Not),
+            MINUS => Some(PrefixOp::Neg),
+            _ => None,
+        }
+    }
+
+    pub fn op_token(&self) -> Option<SyntaxToken> {
+        self.syntax().first_child_or_token()?.as_token()
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub enum BinOp {
+    /// The `||` operator for boolean OR
+    BooleanOr,
+    /// The `&&` operator for boolean AND
+    BooleanAnd,
+    /// The `==` operator for equality testing
+    EqualityTest,
+    /// The `!=` operator for equality testing
+    NegatedEqualityTest,
+    /// The `<=` operator for lesser-equal testing
+    LesserEqualTest,
+    /// The `>=` operator for greater-equal testing
+    GreaterEqualTest,
+    /// The `<` operator for comparison
+    LesserTest,
+    /// The `>` operator for comparison
+    GreaterTest,
+    /// The `+` operator for addition
+    Addition,
+    /// The `*` operator for multiplication
+    Multiplication,
+    /// The `-` operator for subtraction
+    Subtraction,
+    /// The `/` operator for division
+    Division,
+    /// The `%` operator for remainder after division
+    Remainder,
+    /// The `<<` operator for left shift
+    LeftShift,
+    /// The `>>` operator for right shift
+    RightShift,
+    /// The `^` operator for bitwise XOR
+    BitwiseXor,
+    /// The `|` operator for bitwise OR
+    BitwiseOr,
+    /// The `&` operator for bitwise AND
+    BitwiseAnd,
+    /// The `..` operator for right-open ranges
+    RangeRightOpen,
+    /// The `..=` operator for right-closed ranges
+    RangeRightClosed,
+    /// The `=` operator for assignment
+    Assignment,
+    /// The `+=` operator for assignment after addition
+    AddAssign,
+    /// The `/=` operator for assignment after division
+    DivAssign,
+    /// The `*=` operator for assignment after multiplication
+    MulAssign,
+    /// The `%=` operator for assignment after remainders
+    RemAssign,
+    /// The `>>=` operator for assignment after shifting right
+    ShrAssign,
+    /// The `<<=` operator for assignment after shifting left
+    ShlAssign,
+    /// The `-=` operator for assignment after subtraction
+    SubAssign,
+    /// The `|=` operator for assignment after bitwise OR
+    BitOrAssign,
+    /// The `&=` operator for assignment after bitwise AND
+    BitAndAssign,
+    /// The `^=` operator for assignment after bitwise XOR
+    BitXorAssign,
+}
+
+impl ast::BinExpr {
+    fn op_details(&self) -> Option<(SyntaxToken, BinOp)> {
+        self.syntax().children_with_tokens().filter_map(|it| it.as_token()).find_map(|c| {
+            match c.kind() {
+                PIPEPIPE => Some((c, BinOp::BooleanOr)),
+                AMPAMP => Some((c, BinOp::BooleanAnd)),
+                EQEQ => Some((c, BinOp::EqualityTest)),
+                NEQ => Some((c, BinOp::NegatedEqualityTest)),
+                LTEQ => Some((c, BinOp::LesserEqualTest)),
+                GTEQ => Some((c, BinOp::GreaterEqualTest)),
+                L_ANGLE => Some((c, BinOp::LesserTest)),
+                R_ANGLE => Some((c, BinOp::GreaterTest)),
+                PLUS => Some((c, BinOp::Addition)),
+                STAR => Some((c, BinOp::Multiplication)),
+                MINUS => Some((c, BinOp::Subtraction)),
+                SLASH => Some((c, BinOp::Division)),
+                PERCENT => Some((c, BinOp::Remainder)),
+                SHL => Some((c, BinOp::LeftShift)),
+                SHR => Some((c, BinOp::RightShift)),
+                CARET => Some((c, BinOp::BitwiseXor)),
+                PIPE => Some((c, BinOp::BitwiseOr)),
+                AMP => Some((c, BinOp::BitwiseAnd)),
+                DOTDOT => Some((c, BinOp::RangeRightOpen)),
+                DOTDOTEQ => Some((c, BinOp::RangeRightClosed)),
+                EQ => Some((c, BinOp::Assignment)),
+                PLUSEQ => Some((c, BinOp::AddAssign)),
+                SLASHEQ => Some((c, BinOp::DivAssign)),
+                STAREQ => Some((c, BinOp::MulAssign)),
+                PERCENTEQ => Some((c, BinOp::RemAssign)),
+                SHREQ => Some((c, BinOp::ShrAssign)),
+                SHLEQ => Some((c, BinOp::ShlAssign)),
+                MINUSEQ => Some((c, BinOp::SubAssign)),
+                PIPEEQ => Some((c, BinOp::BitOrAssign)),
+                AMPEQ => Some((c, BinOp::BitAndAssign)),
+                CARETEQ => Some((c, BinOp::BitXorAssign)),
+                _ => None,
+            }
+        })
+    }
+
+    pub fn op_kind(&self) -> Option<BinOp> {
+        self.op_details().map(|t| t.1)
+    }
+
+    pub fn op_token(&self) -> Option<SyntaxToken> {
+        self.op_details().map(|t| t.0)
+    }
+
+    pub fn lhs(&self) -> Option<&ast::Expr> {
+        children(self).nth(0)
+    }
+
+    pub fn rhs(&self) -> Option<&ast::Expr> {
+        children(self).nth(1)
+    }
+
+    pub fn sub_exprs(&self) -> (Option<&ast::Expr>, Option<&ast::Expr>) {
+        let mut children = children(self);
+        let first = children.next();
+        let second = children.next();
+        (first, second)
+    }
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub enum LiteralKind {
+    String,
+    ByteString,
+    Char,
+    Byte,
+    IntNumber { suffix: Option<SmolStr> },
+    FloatNumber { suffix: Option<SmolStr> },
+    Bool,
+}
+
+impl ast::Literal {
+    pub fn token(&self) -> SyntaxToken {
+        match self.syntax().first_child_or_token().unwrap() {
+            SyntaxElement::Token(token) => token,
+            _ => unreachable!(),
+        }
+    }
+
+    pub fn kind(&self) -> LiteralKind {
+        match self.token().kind() {
+            INT_NUMBER => {
+                let allowed_suffix_list = [
+                    "isize", "i128", "i64", "i32", "i16", "i8", "usize", "u128", "u64", "u32",
+                    "u16", "u8",
+                ];
+                let text = self.token().text().to_string();
+                let suffix = allowed_suffix_list
+                    .iter()
+                    .find(|&s| text.ends_with(s))
+                    .map(|&suf| SmolStr::new(suf));
+                LiteralKind::IntNumber { suffix }
+            }
+            FLOAT_NUMBER => {
+                let allowed_suffix_list = ["f64", "f32"];
+                let text = self.token().text().to_string();
+                let suffix = allowed_suffix_list
+                    .iter()
+                    .find(|&s| text.ends_with(s))
+                    .map(|&suf| SmolStr::new(suf));
+                LiteralKind::FloatNumber { suffix: suffix }
+            }
+            STRING | RAW_STRING => LiteralKind::String,
+            TRUE_KW | FALSE_KW => LiteralKind::Bool,
+            BYTE_STRING | RAW_BYTE_STRING => LiteralKind::ByteString,
+            CHAR => LiteralKind::Char,
+            BYTE => LiteralKind::Byte,
+            _ => unreachable!(),
+        }
+    }
+}
+
+impl ast::NamedField {
+    pub fn parent_struct_lit(&self) -> &ast::StructLit {
+        self.syntax().ancestors().find_map(ast::StructLit::cast).unwrap()
+    }
+}