C.2 Symbol Types

The symbol type describes the context in which a symbol may be used, and the attributes it supports. Generally, both the compiler and linker must be aware of a given symbol type: the compiler uses the symbol type to determine the type of code to generate, and the linker uses that information to determine what section the object code should be linked to. There are exceptions, noted in their individual sections.

TAME aims to reduce the number of symbol types in favor of a generalized system with few primitives—before defining a new symbol type, consider whether the existing can be reused in a novel way. Certain symbols will be consolidated in the future, time permitting.¹³

rate

Calculation.¹⁴ Calculations yield a single scalar value. If a child cgen exists, the yield of the calculation is equivalent to the sum of all its elements.

gen

Generator.¹⁵ Generators produce a vector element for each iteration of some calculation. Generators always have a parent rate symbol.

class

Classification. Classifications are universal or existential quantifiers most often used as predicates.

cgen

Classification generator.¹⁶ Analogous to gen, produces a boolean element for each classification result. Unlike gen, the dimension of a given cgen is the largest of all of its predicates.

param

Global parameter. All TAME programs can be viewed as a function operating on a set of global inputs. Their domains are defined by their datatype, represented by the symbol attribute dtype (see Symbol Types).

lparam

Local parameter. In contrast to param, local parameters are restricted to a defined scope (e.g. function parameters; let expressions). This symbol is not used by the linker.

lparent

Local parameter parent. This is set for let expressions in place of @parent since the parent let does not actually generate a symbol.

const

Global constant. Constant values (of any dimension). These values may be inlined at the compiler’s discretion.

tpl

Template definition. Templates define expandable text in the form of macros (see Macro Expansion). This symbol is not used by the linker.

type

Datatype. A type describes the domain of a symbol. Types do not include dimension information—such is determined by the dim symbol attribute (see Symbol Format).

func

Function. TAME supports functions as a means of calculation reuse and abstraction. Unlike calculations, functions can recurse (see allow-circular in Symbol Format). Functions are not first-class—TAME is not a functional language.

meta

Arbitrary metadata about the program. These metadata are key-value and are intended to be compiled statically into the program for static reference without having to actually invoke the program.