loki.types.symbol_table

Representation of symbol tables and scopes in Loki’s internal representation (IR)

Classes

SymbolAttributes(dtype, **kwargs)

Representation of a symbol's attributes, such as data type and declared properties

SymbolTable(*args[, case_sensitive])

Lookup table for symbol types that maps symbol names to SymbolAttributes
class SymbolAttributes(dtype, **kwargs)

Bases: object

Representation of a symbol’s attributes, such as data type and declared properties

It has a fixed DataType associated with it, available as property SymbolAttributes.dtype.

Any other properties can be attached on-the-fly, thus allowing to store arbitrary metadata for a symbol, e.g., declaration attributes such as POINTER, ALLOCATABLE, or the shape of an array, or structural information, e.g., whether a variable is a loop index, argument, etc.

There is no need to check for the presence of attributes, undefined attributes can be queried and default to None.

Parameters:

  • dtype (DataType) – The data type associated with the symbol

  • **kwargs (optional) – Any attributes that should be stored as properties

clone(**kwargs)

Clone the SymbolAttributes, optionally overwriting any attributes

Attributes that should be removed should simply be given as None.

compare(other, ignore=None)

Compare SymbolAttributes objects while ignoring a set of select attributes.

Parameters:

  • other (SymbolAttributes) – The object to compare with

  • ignore (iterable, optional) – Names of attributes to ignore while comparing.

Return type:

bool

class SymbolTable(*args, case_sensitive=False, **kwargs)

Bases: dict

Lookup table for symbol types that maps symbol names to SymbolAttributes

It is used to store types for declared variables, defined types or imported symbols within their respective scope. If its associated scope is nested into an enclosing scope, it allows to perform recursive look-ups in parent scopes.

The interface of this table behaves like a dict.

Parameters:

  • parent (SymbolTable, optional) – The symbol table of the parent scope for recursive look-ups.

  • case_sensitive (bool, optional) – Respect the case of symbol names in lookups (default: False).

property parent

The symbol table of the parent scope

Return type:

SymbolTable or None

property case_sensitive

Indicate if the SymbolTable is case-sensitive when looking up names

Return type:

bool

format_lookup_name(name)

Format a variable name for look-up (e.g., convert to lower case if case-insensitive)

Parameters:

name (str) – the name to look up

Returns:

the name used for look-ups

Return type:

str

lookup(name, recursive=True)

Look-up a symbol in the symbol table and return the type or None if not found.

Parameters:

  • name (str) – Name of the type or symbol

  • recursive (bool, optional) – If no entry by that name is found, try to find it in the table of the parent scope

Return type:

SymbolAttributes or None

get(key, default=None)

Get a symbol’s entry without recursive lookup

Parameters:

  • key (str) – Name of the type or symbol

  • default (optional) – Return this value if key is not found in the table

setdefault(key, default=None)

Insert a default value for a key into the table if it does not exist

Parameters:

  • key (str) – Name of the type or symbol

  • default (optional) – The default value to store for the key. Defaults to SymbolAttributes(BasicType.DEFERRED).

update(other)

Update this symbol table with entries from other

clone(**kwargs)

Create a copy of the symbol table with the option to override individual parameters

Parameters:

**kwargs – Any parameters from the constructor of SymbolTable

Returns:

The clone symbol table with copies of all SymbolAttributes

Return type:

SymbolTable