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.
(0-) (tc +)
true
(1+) a
a : symbol
(2+) "hello world"
"hello world" : string
(3+) (= 4 5)
false : boolean
(4+) (* 2.3 2)
4.6 : number
(5+) [1 2 3]
[1 2 3] : (list number)
(6+) (@v 1 2 3 <>)
<1 2 3> : (vector number)
(7+) (@p 1 2 a)
(@p 1 (@p 2 a)) : (number * (number * symbol))
(8+) (@s "10" " green" " bottles")
"10 green bottles" : string
(9+) (freeze (* 7 8))
#<FUNCTION :LAMBDA NIL (multiply 7 8)> : (lazy number)
(10 +) (* 7)
#<FUNCTION :LAMBDA (#:Y18379) (multiply #:Y18378 #:Y18379)> : (number --> number)
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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
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