class Constant

Constant Value.

Implements the Result and AST inteface.

index

static functions

• Constant(type, value, raw)  – construct a new Constant.
• Constant:parse(type, sep)  – create a capture-function (for parsing with Lpeg).
• Constant.wrap(val[, name])  – wrap a Lua value.
• Constant.num(num)  – create a constant number.
• Constant.str(str)  – create a constant string.
• Constant.sym(sym)  – create a constant symbol.
• Constant.bool(bool)  – create a constant boolean.
• Constant.bang()  – create a constant bang.
• Constant.meta(args)  – wrap and document a value.

ast interface

• constant:eval(scope)  – evaluate this literal constant.
• constant:stringify()  – stringify this literal constant.
• constant:clone(prefix)  – clone this literal constant.

result interface

• constant:dirty()  – return whether this Result was changed in the current tick.
• constant:unwrap([type[, msg]])  – unwrap to the Lua type.
• constant:fork()  – create a mutable copy of this stream.
• constant:__call(...)  – alias for unwrap.
• constant.metatype()  – Result metatype.

details

static functions

• Constant(type, value, raw)  – construct a new Constant.

  parameters:

  • type (string): the type name
  • value (any): the Lua value to be accessed through unwrap
  • raw (string): the raw string that resulted in this value. Used by parsing.
• Constant:parse(type, sep)  – create a capture-function (for parsing with Lpeg).

  parameters:

  • type (string): the type name (one of num, sym or str)
  • sep (string): the seperator char (only for str)
• Constant.wrap(val[, name])  – wrap a Lua value.
  Attempts to guess the type and wrap a Lua value.

  parameters:

  • val (any): the value to wrap
  • name (string): the name of this value (for error logging) (optional)

  returns:

  1. (Constant)
• Constant.num(num)  – create a constant number.

  parameters:

  • num (number): the number

  returns:

  1. (Constant)
• Constant.str(str)  – create a constant string.

  parameters:

  • str (string): the string

  returns:

  1. (Constant)
• Constant.sym(sym)  – create a constant symbol.

  parameters:

  • sym (string): the symbol

  returns:

  1. (Constant)
• Constant.bool(bool)  – create a constant boolean.

  parameters:

  • bool (boolean): the boolean

  returns:

  1. (Constant)
• Constant.bang()  – create a constant bang.

  returns:

  1. (Constant)
• Constant.meta(args)  – wrap and document a value.
  wraps args.value using wrap, then assigns meta.

  parameters:

  • args (table): table with keys value and meta

  returns:

  1. (Constant)

ast interface

• constant:eval(scope)  – evaluate this literal constant.
  Throws an error if type is not a literal (num, str or sym). Returns an eval-time const result for num and str. Resolves syms in scope and returns a reference to them.

  parameters:

  • scope (Scope): the scope to evaluate in

  returns:

  1. (RTNode): the evaluation result
• constant:stringify()  – stringify this literal constant.
  Throws an error if raw is not set.

  returns:

  1. (string): the exact string this stream was parsed from
• constant:clone(prefix)  – clone this literal constant.

  parameters:

  • prefix

  returns:

  1. (SignStream): self

result interface

• constant:dirty()  – return whether this Result was changed in the current tick.

  returns:

  1. (bool)
• constant:unwrap([type[, msg]])  – unwrap to the Lua type.
  Asserts @type == type if type is given.

  parameters:

  • type (string): the type to check for (optional)
  • msg (string): message to throw if type don’t match (optional)

  returns:

  1. (any): value
• constant:fork()  – create a mutable copy of this stream.
  Used to insulate eval-cycles from each other.

  returns:

  1. (Constant)
• constant:__call(...)  – alias for unwrap.

  parameters:

  • ...
• constant.metatype()  – Result metatype.