Enum Expr 

pub enum Expr {
    Num(f64),
    Str(StringExpr),
    Index(Vec<Expr>),
    Var(String, Option<Box<Expr>>),
    Env(EnvVar),
    Unary(UnOp, Box<Expr>),
    Bin(BinOp, Box<Expr>, Box<Expr>),
    Func1(Func1, Box<Expr>),
    Func2(Func2, Box<Expr>, Box<Expr>),
    Rand(Option<Box<Expr>>),
    Assign(String, Option<Box<Expr>>, Box<Expr>),
    DotX(Location),
    DotY(Location),
    PlaceAttr(Place, Param),
}

A scalar (numeric / boolean) expression. pic treats booleans as numbers.

Variants

Num(f64)

Str(StringExpr)

A string operand, valid only as an operand of ==/!= (pic compares strings for equality, e.g. the "$1"=="" default-argument idiom).

Index(Vec<Expr>)

Comma-separated array subscript, valid only inside name[...].

Var(String, Option<Box<Expr>>)

Env(EnvVar)

Unary(UnOp, Box<Expr>)

Bin(BinOp, Box<Expr>, Box<Expr>)

Func1(Func1, Box<Expr>)

Func2(Func2, Box<Expr>, Box<Expr>)

Rand(Option<Box<Expr>>)

Assign(String, Option<Box<Expr>>, Box<Expr>)

( name = expr ) — assign and yield the assigned value.

DotX(Location)

DotY(Location)

PlaceAttr(Place, Param)

Trait Implementations

impl Clone for Expr

fn clone(&self) -> Expr

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Expr

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Expr

fn eq(&self, other: &Expr) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Expr