Evaluation

kesh is line-oriented.

Lines

• Code is evaluated line-by-line, top to bottom
• Lines are separated by either newline or comma ,
• There are two types of lines:
  1. Declaration lines
  2. Expression lines

Blocks

• A block {} consists of lines
  • Declaration lines
  • Expression lines
• A block has its own (lexical) scope
• A block's value is the value of its last evaluated expression line
• A block is an expression

Collections

• A collection [] consists of lines
  • Declaration lines if object
  • Expression lines if other type
• Collection is a reference type

Tuples

• A tuple () consists of lines
  • Expression lines
• Tuple is a reference type, ideally it would have value semantics

Functions

• A function -> consists of parameters and a body
  • Its parameters is the unpacking of its argument, as either a tuple or a collection
    • The unpacked argument's values exist in the function scope
  • Its body is an expression, typically a block
• Function is a reference type, being also a collection
  • A function is a callable collection