Basic Types and Constructors


 

 

8. Basic Types and Constructors

TBoS p.213, Types

The basic datatypes and types of Shen are;

  • symbols
  • strings
  • booleans
  • numbers
  • lists
  • tuples
  • vectors
  • exceptions
  • lazy objects
  • abstractions

Typing (tc +) to the REPL activates type checking. Here are a few examples.

a
a : symbol

"hello world"
"hello world" : string

(= 4 5)
false : boolean

(* 2.3 2)
4.6 : number

[1 2 3]
[1 2 3] : (list number)

(@v 1 2 3 <>)
<1 2 3> : (vector number)

(@p 1 2 a)
(@p 1 (@p 2 a)) : (number * (number * symbol))

(@s "10" " green" " bottles")
"10 green bottles" : string

(freeze (* 7 8))
# : (lazy number)

(10 +) (* 7)
# : (number --> number)
1. Introduction

2. License

3. History

4. The Core Language

4.1 Base Types
4.1.1 Symbols
4.1.2 Strings
4.1.3 Numbers
4.2 Function Applications
4.3 The Top Level
4.4 Arithmetic
4.5 Comments

4.6 Sequences

4.6.1 Lists
4.6.2 Tuples
4.6.3 Vectors

4.7 lambda and let
4.8 Global Assignments
4.9 Higher Order Functions
4.10 Lazy Evaluation
4.11 I/O
4.12 Loading Files
4.13 Streams
4.14 Exceptions
4.15 Hashing
4.16 Property Lists
4.17 Eval

5 Defining Functions

5.1 Partial Functions
5.2 List Handling Functions
5.3 String Handling Functions
5.4 Tuple Handling Functions
5.5 Vector Handling Functions
5.6 Guards
5.7 Backtracking
5.8 Writing in Kλ
5.9 Macros

6. Packages

7. Shen-YACC

7.1 Recognisor Generator
7.2 Semantic Actions

8. Shen Prolog

8.1 Sample Programs

9. Types

9.1 Types and Constructors
9.2 Functions and Types
9.3 Synonyms

10 Sequent Calculus

10.1 Recursive Types

10.2 Exotic Types

10.2.1 Dependent Types
10.2.2 Negative Types
10.2.3 Subtypes
10.2.4 The Type of All Sets

11 Glossary of Functions

12 The Syntax of Shen

Built by Shen Technology (c) Mark Tarver, September 2021