Struct endbasic_core::syms::Symbols

pub struct Symbols { /* private fields */ }

Storage for all symbols that exist at runtime.

Symbols are represented as a two-layer map: the globals map contains all symbols that are visible by all scopes, and the scope contains all symbols that are only visible within a given scope.

The collection of symbols that is visible at any given point in time is thus the union of the global symbols and the symbols in the last scope.

Scopes are represented as a stack in order to support nested function calls.

Implementations

impl Symbols

pub fn add_callable(&mut self, callable: Rc<dyn Callable>)

Registers the given builtin callable as a global symbol.

Given that callables cannot be defined at runtime, specifying a non-unique name results in a panic.

pub fn callables(&self) -> HashMap<&SymbolKey, Rc<dyn Callable>>

Returns the mapping of all callables.

pub fn locals(&self) -> &HashMap<SymbolKey, Symbol>

Returns the mapping of all symbols in the current scope that are not globals.

pub fn clear(&mut self)

Clears all user-defined symbols.

pub fn dim(&mut self, key: SymbolKey, etype: ExprType)

Defines a new local variable key of type etype. The variable must not yet exist.

pub fn dim_shared(&mut self, key: SymbolKey, etype: ExprType)

Defines a new global variable key of type etype. The variable must not yet exist.

pub fn dim_array( &mut self, key: SymbolKey, subtype: ExprType, dimensions: Vec<usize>, )

Defines a new array key of type subtype with dimensions. The array must not yet exist, and the name may not overlap function or variable names.

pub fn dim_shared_array( &mut self, key: SymbolKey, subtype: ExprType, dimensions: Vec<usize>, )

Defines a new global array key of type subtype with dimensions. The array must not yet exist, and the name may not overlap function or variable names.

pub fn get(&self, vref: &VarRef) -> Result<Option<&Symbol>>

Obtains the value of a symbol or None if it is not defined.

Returns an error if the type annotation in the symbol reference does not match its type.

pub fn get_auto(&self, var: &str) -> Option<&Symbol>

Obtains the value of a symbol or None if it is not defined.

pub fn get_mut(&mut self, vref: &VarRef) -> Result<Option<&mut Symbol>>

Obtains the value of a symbol or None if it is not defined.

Returns an error if the type annotation in the symbol reference does not match its type.

pub fn set_var(&mut self, vref: &VarRef, value: Value) -> Result<()>

Sets the value of a variable.

If vref contains a type annotation, the type of the value must be compatible with that type annotation.

If the variable is already defined, then the type of the new value must be compatible with the existing variable. In other words: a variable cannot change types while it’s alive.

Trait Implementations

impl Default for Symbols

fn default() -> Self

Returns the “default value” for a type.