首页 / Documentation

文档

解释器目前接受什么的参考。凡是尚未实现的部分，参考中如实说明，而不是略去不提。

本节尚未翻译成你的语言，暂时以英文显示。欢迎提交翻译。

值

Type	Means	Written as
nil	The absence of a value, and the result of a branch with no alternative.	nil
boolean	True or false. Only false is falsey.	`#t` `#f`
integer	A signed 64-bit integer.	42 -7
float	A double-precision number.	3.14
rune	A Unicode code point.	`\u00e9`
string	An immutable sequence of bytes, written as text.	"hello"
symbol	An interned name. Evaluating one looks it up.	foo bar?
keyword	An interned name that evaluates to itself.	:a
pair	A cons cell: a value and the rest of the list.	`(1 2 3)` `'()`
vector	An immutable indexed sequence.	`[1 2 3]`
table	An immutable string-keyed map with sorted keys, so output is stable.	`{:a 1}`
array	A mutable indexed sequence.	`@[1 2 3]`
closure	A procedure and the environment it captured.	`(lambda (x) ...)`
primitive	A built-in procedure implemented in V.	`+` `car`

本节尚未翻译成你的语言，暂时以英文显示。欢迎提交翻译。

核心形式

Form	Meaning	Desugars to
if	Evaluate the test, then one branch. With no alternative the result is nil.	`if`
define	Bind a name in the current frame. A list target defines a procedure.	`define`
set!	Assign to the frame that owns the binding, so a closure sees the change on its next call.	`set!`
lambda	Create a procedure. fn is a synonym.	`lambda`, `fn`
begin	Evaluate in order, return the last. The last form keeps its tail position, so tail calls inside a begin are still tail calls.	`begin`
let	Bind names and evaluate the body in a new frame. let binds simultaneously, let* in order, letrec with every name visible to every value.	`let`, `let*`, `letrec`
and	Short-circuit. Return the first falsey value, or the last value.	`and`, `or`
quote	Return the form itself instead of evaluating it. The apostrophe is shorthand.	`quote`

本节尚未翻译成你的语言，暂时以英文显示。欢迎提交翻译。

派生形式

Form	Meaning	Desugars to
when	Run the body only if the test is true, otherwise nil.	`if`
unless	Run the body only if the test is false, otherwise nil.	`if`
cond	Try clauses in order and take the first whose test is true. => separates test from body.	nested `if`
case	Compare one value against a list of candidates per clause.	`cond`
loop	A named let: bind the variable, run the body while the test holds, and advance the variable each round.	named `let`
dotimes	loop with an implicit counter from zero.	`loop`

本节尚未翻译成你的语言，暂时以英文显示。欢迎提交翻译。

关于真值

Only #f is false. The number zero, the empty string, nil, and the empty list are all true. This matches R5RS and Clojure, and deliberately does not match Ruby, JavaScript, or Python.

The rule matters more than it looks. A language that treats 0 as falsey makes every numeric result a potential branch, which is why code in those languages needs explicit nil checks that vlip code does not.

本节尚未翻译成你的语言，暂时以英文显示。欢迎提交翻译。

原始函数

Form	Meaning	Desugars to
arithmetic	Whole numbers, with promotion when a float is involved.	`+` `-` `*` `/` `%`
comparison	Return #t or #f.	`=` `<` `>` `<=` `>=`
logic	Negation. and and or are forms, not primitives, because they short-circuit.	`not`
lists	Build and take apart cons cells.	`car` `cdr` `cons` `list` `null?`
sequences	Take a procedure and a list, and return a new list.	`map` `filter` `fold` `apply`
output	Write to the machine's output buffer, not straight to a terminal, so a host can capture it.	`print` `println`

本节尚未翻译成你的语言，暂时以英文显示。欢迎提交翻译。

尚未实现

let* and rest parameters are written in the examples and do not yet evaluate correctly. Callable keywords do not work either.

The cause of the let* failure is a real design question rather than a typo: [ ] is a vector literal in a value position and a binding group in a form position, and the reader does not yet record which reading applies. It is written up in the roadmap.