Fixes to language documentation
- Use backticks consistently for inline code - Capitalize section headers and proper nouns - Minor grammatical fixes
This commit is contained in:
Kevin Yap
parent
7d0fe31ebe
commit
997501bcc4
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@ -13,14 +13,14 @@ Theory of Hy
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Hy maintains, over everything else, 100% compatibility in both directions
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Hy maintains, over everything else, 100% compatibility in both directions
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with Python itself. All Hy code follows a few simple rules. Memorize
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with Python itself. All Hy code follows a few simple rules. Memorize
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this, it's going to come in handy.
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this, as it's going to come in handy.
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These rules help make sure code is idiomatic and interface-able in both
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These rules help ensure that Hy code is idiomatic and interface-able in both
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languages.
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languages.
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* Symbols in earmufs will be translated to the uppercased version of that
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* Symbols in earmufs will be translated to the upper-cased version of that
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string. For example, `*foo*` will become `FOO`.
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string. For example, `foo` will become `FOO`.
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* UTF-8 entities will be encoded using
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* UTF-8 entities will be encoded using
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`punycode <http://en.wikipedia.org/wiki/Punycode>`_ and prefixed with
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`punycode <http://en.wikipedia.org/wiki/Punycode>`_ and prefixed with
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@ -33,8 +33,8 @@ languages.
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versa.
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versa.
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Builtins
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Built-Ins
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========
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=========
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Hy features a number of special forms that are used to help generate
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Hy features a number of special forms that are used to help generate
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correct Python AST. The following are "special" forms, which may have
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correct Python AST. The following are "special" forms, which may have
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@ -47,7 +47,7 @@ behavior that's slightly unexpected in some situations.
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`.` is used to perform attribute access on objects. It uses a small DSL
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`.` is used to perform attribute access on objects. It uses a small DSL
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to allow quick access to attributes and items in a nested datastructure.
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to allow quick access to attributes and items in a nested data structure.
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For instance,
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For instance,
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@ -69,7 +69,7 @@ indexation. Other arguments throw a compilation error.
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Access to unknown attributes throws an :exc:`AttributeError`. Access to
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Access to unknown attributes throws an :exc:`AttributeError`. Access to
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unknown keys throws an :exc:`IndexError` (on lists and tuples) or a
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unknown keys throws an :exc:`IndexError` (on lists and tuples) or a
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:exc:`KeyError` (on dicts).
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:exc:`KeyError` (on dictionaries).
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->
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->
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--
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--
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@ -89,7 +89,7 @@ The following code demonstrates this:
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---
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---
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`->>` or `threading tail macro` is similar to `threading macro` but instead of
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`->>` or `threading tail macro` is similar to `threading macro` but instead of
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inserting each expression into the next expression’s first argument place, it
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inserting each expression into the next expression’s first argument, it
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appends it as the last argument. The following code demonstrates this:
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appends it as the last argument. The following code demonstrates this:
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.. code-block:: clj
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.. code-block:: clj
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@ -133,9 +133,9 @@ Examples:
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and
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and
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---
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---
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`and` form is used in logical expressions. It takes at least two parameters. If
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`and` is used in logical expressions. It takes at least two parameters. If all
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all parameters evaluate to `True` the last parameter is returned. In any other
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parameters evaluate to `True`, the last parameter is returned. In any other
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case the first false value will be returned. Examples of usage:
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case, the first false value will be returned. Example usage:
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.. code-block:: clj
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.. code-block:: clj
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@ -179,10 +179,10 @@ or `False`.
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assoc
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assoc
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-----
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-----
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`assoc` form is used to associate a key with a value in a dictionary or to set
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`assoc` is used to associate a key with a value in a dictionary or to set an
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an index of a list to a value. It takes at least three parameters: `datastructure`
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index of a list to a value. It takes at least three parameters: the `data
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to be modified, `key` or `index` and `value`. If more than three parameters are
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structure` to be modified, `key` or `index` and `value`. If more than three
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used it will associate in pairs.
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parameters are used, it will associate in pairs.
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Examples of usage:
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Examples of usage:
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@ -210,9 +210,8 @@ break
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-----
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-----
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`break` is used to break out from a loop. It terminates the loop immediately.
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`break` is used to break out from a loop. It terminates the loop immediately.
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The following example has an infinite `while` loop that is terminated as soon
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The following example has an infinite while loop that is terminated as soon as
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as the user enters `k`.
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the user enters `k`.
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.. code-block:: clj
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.. code-block:: clj
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@ -224,10 +223,8 @@ the user enters `k`.
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cond
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cond
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----
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----
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`cond` macro can be used to build nested if-statements.
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`cond` can be used to build nested if-statements. The following example shows
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the relationship between the macro and the expanded code:
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The following example shows the relationship between the macro and the expanded
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code:
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.. code-block:: clj
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.. code-block:: clj
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@ -289,10 +286,10 @@ the sequence based on a conditional expression.
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do / progn
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do / progn
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----------
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----------
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the `do` and `progn` forms are used to evaluate each of their arguments and
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`do` and `progn` are used to evaluate each of their arguments and return the last
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return the last one. Return values from every other than the last argument are
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one. Return values from every other than the last argument are discarded. It can be
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discarded. It can be used in `lambda` or `list-comp` to perform more complex
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used in `lambda` or `list-comp` to perform more complex logic as shown by one of the
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logic as shown by one of the examples.
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examples.
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Some example usage:
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Some example usage:
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@ -316,9 +313,9 @@ Some example usage:
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def / setv
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def / setv
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-----------------
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----------
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`def` and `setv` are used to bind value, object or a function to a symbol. For
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`def` and `setv` are used to bind a value, object, or function to a symbol. For
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example:
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example:
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.. code-block:: clj
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.. code-block:: clj
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@ -335,7 +332,7 @@ example:
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defclass
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defclass
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--------
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--------
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new classes are declared with `defclass`. It can takes two optional parameters:
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New classes are declared with `defclass`. It can takes two optional parameters:
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a vector defining a possible super classes and another vector containing
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a vector defining a possible super classes and another vector containing
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attributes of the new class as two item vectors.
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attributes of the new class as two item vectors.
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@ -367,17 +364,17 @@ defn / defun
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------------
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------------
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`defn` and `defun` macros are used to define functions. They take three
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`defn` and `defun` macros are used to define functions. They take three
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parameters: `name` of the function to define, vector of `parameters` and the
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parameters: the `name` of the function to define, a vector of `parameters`,
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`body` of the function:
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and the `body` of the function:
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.. code-block:: clj
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.. code-block:: clj
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(defn name [params] body)
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(defn name [params] body)
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Parameters may have following keywords in front of them:
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Parameters may have the following keywords in front of them:
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&optional
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&optional
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parameter is optional. The parameter can be given as a two item list, where
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Parameter is optional. The parameter can be given as a two item list, where
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the first element is parameter name and the second is the default value. The
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the first element is parameter name and the second is the default value. The
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parameter can be also given as a single item, in which case the default
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parameter can be also given as a single item, in which case the default
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value is None.
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value is None.
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@ -397,7 +394,7 @@ Parameters may have following keywords in front of them:
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&kwargs
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&kwargs
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parameter will contain 0 or more keyword arguments.
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Parameter will contain 0 or more keyword arguments.
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The following code examples defines a function that will print all keyword
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The following code examples defines a function that will print all keyword
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arguments and their values.
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arguments and their values.
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@ -412,7 +409,7 @@ Parameters may have following keywords in front of them:
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parameter-1 1
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parameter-1 1
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&rest
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&rest
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parameter will contain 0 or more positional arguments. No other positional
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Parameter will contain 0 or more positional arguments. No other positional
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arguments may be specified after this one.
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arguments may be specified after this one.
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The following code example defines a function that can be given 0 to n
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The following code example defines a function that can be given 0 to n
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@ -463,8 +460,8 @@ defmain
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.. versionadded:: 0.10.1
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.. versionadded:: 0.10.1
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The `defmain` macro defines a main function that is immediately called
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The `defmain` macro defines a main function that is immediately called
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with sys.argv as arguments if and only if this file is being executed
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with ``sys.argv`` as arguments if and only if this file is being executed
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as a script. In other words this:
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as a script. In other words, this:
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.. code-block:: clj
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.. code-block:: clj
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@ -484,7 +481,7 @@ is the equivalent of::
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if isinstance(retval, int):
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if isinstance(retval, int):
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sys.exit(retval)
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sys.exit(retval)
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Note, as you can see above, if you return an integer from this
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Note that as you can see above, if you return an integer from this
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function, this will be used as the exit status for your script.
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function, this will be used as the exit status for your script.
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(Python defaults to exit status 0 otherwise, which means everything's
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(Python defaults to exit status 0 otherwise, which means everything's
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okay!)
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okay!)
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@ -596,7 +593,7 @@ del
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File "<console>", line 1, in <module>
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File "<console>", line 1, in <module>
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NameError: name 'foo' is not defined
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NameError: name 'foo' is not defined
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`del` can also remove objects from a mapping, a list, ...
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`del` can also remove objects from mappings, lists, and more.
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.. code-block:: clj
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.. code-block:: clj
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@ -618,7 +615,7 @@ doto
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.. versionadded:: 0.10.1
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.. versionadded:: 0.10.1
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`doto` macro is used to make a sequence of method calls for an object easy.
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`doto` macro is used to simplify a sequence of method calls to an object.
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.. code-block:: clj
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.. code-block:: clj
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@ -664,11 +661,11 @@ first / car
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for
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for
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-------
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---
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`for` is used to call a function for each element in a list or vector.
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`for` is used to call a function for each element in a list or vector.
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The results of each call are discarded and the for expression returns
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The results of each call are discarded and the for expression returns
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None instead. The example code iterates over `collection` and
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`None` instead. The example code iterates over `collection` and
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for each `element` in `collection` calls the `side-effect`
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for each `element` in `collection` calls the `side-effect`
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function with `element` as its argument:
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function with `element` as its argument:
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@ -728,7 +725,7 @@ gensym
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.. versionadded:: 0.9.12
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.. versionadded:: 0.9.12
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`gensym` form is used to generate a unique symbol to allow writing macros
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`gensym` is used to generate a unique symbol to allow writing macros
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without accidental variable name clashes.
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without accidental variable name clashes.
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.. code-block:: clj
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.. code-block:: clj
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@ -746,10 +743,10 @@ without accidental variable name clashes.
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get
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get
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---
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---
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`get` form is used to access single elements in lists and dictionaries. `get`
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`get` is used to access single elements in lists and dictionaries. `get` takes
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takes two parameters, the `datastructure` and the `index` or `key` of the item.
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two parameters: the `data structure` and the `index` or `key` of the item.
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It will then return the corresponding value from the dictionary or the list.
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It will then return the corresponding value from the dictionary or the list.
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Example usages:
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Example usage:
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.. code-block:: clj
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.. code-block:: clj
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@ -772,11 +769,11 @@ global
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`global` can be used to mark a symbol as global. This allows the programmer to
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`global` can be used to mark a symbol as global. This allows the programmer to
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assign a value to a global symbol. Reading a global symbol does not require the
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assign a value to a global symbol. Reading a global symbol does not require the
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`global` keyword, just the assigning does.
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`global` keyword -- only assigning it does.
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Following example shows how global `a` is assigned a value in a function and later
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The following example shows how the global symbol `a` is assigned a value in a
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on printed on another function. Without the `global` keyword, the second function
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function and is later on printed in another function. Without the `global` keyword,
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would thrown a `NameError`.
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the second function would have thrown a `NameError`.
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.. code-block:: clj
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.. code-block:: clj
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@ -793,29 +790,32 @@ would thrown a `NameError`.
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if / if-not
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if / if-not
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-----------
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-----------
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the `if` form is used to conditionally select code to be executed. It has to
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.. versionadded:: 0.10.0
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contain the condition block and the block to be executed if the condition
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if-not
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evaluates `True`. Optionally it may contain a block that is executed in case
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the evaluation of the condition is `False`. The `if-not` form (*new in
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`if` is used to conditionally select code to be executed. It has to contain a
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0.10.0*) is similar, but the first block after the test will be
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condition block and the block to be executed if the condition block evaluates
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executed when the test fails, while the other, conditional one, when
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to `True`. Optionally, it may contain a final block that is executed in case
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the test succeeds - opposite of the order of the `if` form.
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the evaluation of the condition is `False`. The `if-not` form is similar, but
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the second block will be executed when the condition fails while the third and
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final block is executed when the test succeeds -- the opposite order of the `if`
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form.
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Example usage:
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Example usage:
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.. code-block:: clj
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.. code-block:: clj
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(if (money-left? account)
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(if (money-left? account)
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(print "lets go shopping")
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(print "let's go shopping")
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(print "lets go and work"))
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(print "let's go and work"))
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(if-not (money-left? account)
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(if-not (money-left? account)
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(print "lets go and work")
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(print "let's go and work")
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(print "lets go shopping"))
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(print "let's go shopping"))
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Truth values of Python objects are respected. Values `None`, `False`, zero of
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Truth values of Python objects are respected. `None`, `False`, zero of any numeric
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any numeric type, empty sequence and empty dictionary are considered `False`.
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type, an empty sequence, and an empty dictionary are considered `False`. Everything else
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Everything else is considered `True`.
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is considered `True`.
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lisp-if / lif and lisp-if-not / lif-not
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lisp-if / lif and lisp-if-not / lif-not
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@ -826,10 +826,10 @@ lisp-if / lif and lisp-if-not / lif-not
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.. versionadded:: 0.10.2
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.. versionadded:: 0.10.2
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lisp-if-not / lif-not
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lisp-if-not / lif-not
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For those that prefer a more lisp-y if clause, we have lisp-if, or lif. This
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For those that prefer a more Lispy `if` clause, we have `lisp-if`, or `lif`. This
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*only* considers None/nil as false! All other values of python
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*only* considers `None`/`nil` as false! All other "false-ish" Python values are
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"falseiness" are considered true. Conversely, we have lisp-if-not or lif-not,
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considered true. Conversely, we have `lisp-if-not` and `lif-not` in parallel to
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in parallel to if / if-not, which reverses the comparison.
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`if` and `if-not` which reverses the comparison.
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.. code-block:: clj
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.. code-block:: clj
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@ -851,7 +851,7 @@ in parallel to if / if-not, which reverses the comparison.
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=> (lisp-if-not False "true" "false")
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=> (lisp-if-not False "true" "false")
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"false"
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"false"
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; And, same thing
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; Equivalent but shorter
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=> (lif True "true" "false")
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=> (lif True "true" "false")
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"true"
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"true"
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=> (lif nil "true" "false")
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=> (lif nil "true" "false")
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@ -898,9 +898,9 @@ lambda / fn
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-----------
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-----------
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`lambda` and `fn` can be used to define an anonymous function. The parameters are
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`lambda` and `fn` can be used to define an anonymous function. The parameters are
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similar to `defn`: first parameter is vector of parameters and the rest is the
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similar to `defn`: the first parameter is vector of parameters and the rest is the
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body of the function. lambda returns a new function. In the example an anonymous
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body of the function. `lambda` returns a new function. In the following example, an
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function is defined and passed to another function for filtering output.
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anonymous function is defined and passed to another function for filtering output.
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.. code-block:: clj
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.. code-block:: clj
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@ -927,7 +927,7 @@ class methods docstrings.
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... "Multiplies input by three and returns the result."
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... "Multiplies input by three and returns the result."
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... (* x 3)))
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... (* x 3)))
|
||||||
|
|
||||||
Then test it via the Python built-in ``help`` function::
|
This can be confirmed via Python's built-in ``help`` function::
|
||||||
|
|
||||||
=> (help times-three)
|
=> (help times-three)
|
||||||
Help on function times_three:
|
Help on function times_three:
|
||||||
|
|
@ -941,7 +941,7 @@ let
|
||||||
---
|
---
|
||||||
|
|
||||||
`let` is used to create lexically scoped variables. They are created at the
|
`let` is used to create lexically scoped variables. They are created at the
|
||||||
beginning of `let` form and cease to exist after the form. The following
|
beginning of the `let` form and cease to exist after the form. The following
|
||||||
example showcases this behaviour:
|
example showcases this behaviour:
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
@ -953,10 +953,10 @@ example showcases this behaviour:
|
||||||
6
|
6
|
||||||
5
|
5
|
||||||
|
|
||||||
`let` macro takes two parameters: a vector defining `variables` and `body`,
|
The `let` macro takes two parameters: a vector defining `variables` and the
|
||||||
which is being executed. `variables` is a vector where each element is either
|
`body` which gets executed. `variables` is a vector where each element is either
|
||||||
a single variable or a vector defining a variable value pair. In case of a
|
a single variable or a vector defining a variable value pair. In the case of a
|
||||||
single variable, it is assigned value None, otherwise the supplied value is
|
single variable, it is assigned value `None`; otherwise, the supplied value is
|
||||||
used.
|
used.
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
@ -990,9 +990,9 @@ conditional expression. Some examples:
|
||||||
not
|
not
|
||||||
---
|
---
|
||||||
|
|
||||||
`not` form is used in logical expressions. It takes a single parameter and
|
`not` is used in logical expressions. It takes a single parameter and
|
||||||
returns a reversed truth value. If `True` is given as a parameter, `False`
|
returns a reversed truth value. If `True` is given as a parameter, `False`
|
||||||
will be returned and vice-versa. Examples for usage:
|
will be returned and vice-versa. Example usage:
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
||||||
|
|
@ -1009,8 +1009,8 @@ will be returned and vice-versa. Examples for usage:
|
||||||
or
|
or
|
||||||
--
|
--
|
||||||
|
|
||||||
`or` form is used in logical expressions. It takes at least two parameters. It
|
`or` is used in logical expressions. It takes at least two parameters. It will
|
||||||
will return the first non-false parameter. If no such value exist, the last
|
return the first non-false parameter. If no such value exists, the last
|
||||||
parameter will be returned.
|
parameter will be returned.
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
@ -1024,8 +1024,8 @@ parameter will be returned.
|
||||||
=> (and False 1 True False)
|
=> (and False 1 True False)
|
||||||
1
|
1
|
||||||
|
|
||||||
.. note:: `or` shortcuts and stops evaluating parameters as soon as the first
|
.. note:: `or` short-circuits and stops evaluating parameters as soon as the
|
||||||
true is encountered.
|
first true value is encountered.
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
||||||
|
|
@ -1036,7 +1036,7 @@ parameter will be returned.
|
||||||
print
|
print
|
||||||
-----
|
-----
|
||||||
|
|
||||||
the `print` form is used to output on screen. Example usage:
|
`print` is used to output on screen. Example usage:
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
||||||
|
|
@ -1048,11 +1048,11 @@ the `print` form is used to output on screen. Example usage:
|
||||||
quasiquote
|
quasiquote
|
||||||
----------
|
----------
|
||||||
|
|
||||||
`quasiquote` allows you to quote a form, but also to
|
`quasiquote` allows you to quote a form, but also selectively evaluate
|
||||||
selectively evaluate expressions, expressions inside a `quasiquote`
|
expressions. Expressions inside a `quasiquote` can be selectively evaluated
|
||||||
can be selectively evaluated using `unquote` (~). The evaluated form can
|
using `unquote` (~). The evaluated form can also be spliced using
|
||||||
also be spliced using `unquote-splice` (~@). Quasiquote can be also written
|
`unquote-splice` (~@). Quasiquote can be also written using the backquote (`)
|
||||||
using the backquote (`) symbol.
|
symbol.
|
||||||
|
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
@ -1067,7 +1067,7 @@ using the backquote (`) symbol.
|
||||||
quote
|
quote
|
||||||
-----
|
-----
|
||||||
|
|
||||||
`quote` returns the form passed to it without evaluating. `quote` can
|
`quote` returns the form passed to it without evaluating it. `quote` can
|
||||||
be alternatively written using the (') symbol
|
be alternatively written using the (') symbol
|
||||||
|
|
||||||
|
|
||||||
|
|
@ -1129,13 +1129,11 @@ slice
|
||||||
`slice` can be used to take a subset of a list and create a new list from it.
|
`slice` can be used to take a subset of a list and create a new list from it.
|
||||||
The form takes at least one parameter specifying the list to slice. Two
|
The form takes at least one parameter specifying the list to slice. Two
|
||||||
optional parameters can be used to give the start and end position of the
|
optional parameters can be used to give the start and end position of the
|
||||||
subset. If they are not supplied, default value of None will be used instead.
|
subset. If they are not supplied, default value of `None` will be used instead.
|
||||||
Third optional parameter is used to control step between the elements.
|
The third optional parameter is used to control step between the elements.
|
||||||
|
|
||||||
`slice` follows the same rules as the Python counterpart. Negative indecies are
|
`slice` follows the same rules as its Python counterpart. Negative indices are
|
||||||
counted starting from the end of the list.
|
counted starting from the end of the list. Some example usage:
|
||||||
Some examples of
|
|
||||||
usage:
|
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
||||||
|
|
@ -1160,10 +1158,8 @@ usage:
|
||||||
throw / raise
|
throw / raise
|
||||||
-------------
|
-------------
|
||||||
|
|
||||||
the `throw` or `raise` forms can be used to raise an Exception at runtime.
|
The `throw` or `raise` forms can be used to raise an `Exception` at runtime.
|
||||||
|
Example usage:
|
||||||
|
|
||||||
Example usage
|
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
||||||
|
|
@ -1177,15 +1173,15 @@ Example usage
|
||||||
; Throw an IOError("foobar")
|
; Throw an IOError("foobar")
|
||||||
|
|
||||||
|
|
||||||
`throw` can accept a single argument (an `Exception` class or instance), or
|
`throw` can accept a single argument (an `Exception` class or instance) or
|
||||||
no arguments to re-raise the last Exception.
|
no arguments to re-raise the last `Exception`.
|
||||||
|
|
||||||
|
|
||||||
try
|
try
|
||||||
---
|
---
|
||||||
|
|
||||||
the `try` form is used to start a `try` / `catch` block. The form is used
|
The `try` form is used to start a `try` / `catch` block. The form is used
|
||||||
as follows
|
as follows:
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
||||||
|
|
@ -1197,16 +1193,17 @@ as follows
|
||||||
|
|
||||||
`try` must contain at least one `catch` block, and may optionally have an
|
`try` must contain at least one `catch` block, and may optionally have an
|
||||||
`else` or `finally` block. If an error is raised with a matching catch
|
`else` or `finally` block. If an error is raised with a matching catch
|
||||||
block during execution of `error-prone-function` then that catch block will
|
block during execution of `error-prone-function`, that catch block will
|
||||||
be executed. If no errors are raised the `else` block is executed. Regardless
|
be executed. If no errors are raised, the `else` block is executed. The
|
||||||
if an error was raised or not, the `finally` block is executed as last.
|
`finally` block will be executed last, regardless of whether or not an error
|
||||||
|
was raised.
|
||||||
|
|
||||||
|
|
||||||
unless
|
unless
|
||||||
------
|
------
|
||||||
|
|
||||||
`unless` macro is a shorthand for writing a if-statement that checks if the
|
The `unless` macro is a shorthand for writing an `if` statement that checks if the
|
||||||
given conditional is False. The following shows how the macro expands into code.
|
given conditional is `False`. The following shows the expansion of this macro.
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
||||||
|
|
@ -1256,8 +1253,8 @@ when
|
||||||
----
|
----
|
||||||
|
|
||||||
`when` is similar to `unless`, except it tests when the given conditional is
|
`when` is similar to `unless`, except it tests when the given conditional is
|
||||||
True. It is not possible to have an `else` block in `when` macro. The following
|
`True`. It is not possible to have an `else` block in a `when` macro. The following
|
||||||
shows how the macro is expanded into code.
|
shows the expansion of the macro.
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
||||||
|
|
@ -1268,10 +1265,8 @@ shows how the macro is expanded into code.
|
||||||
while
|
while
|
||||||
-----
|
-----
|
||||||
|
|
||||||
`while` form is used to execute a single or more blocks as long as a condition
|
`while` is used to execute one or more blocks as long as a condition is met.
|
||||||
is being met.
|
The following example will output "hello world!" to the screen indefinitely:
|
||||||
|
|
||||||
The following example will output "hello world!" on screen indefinitely:
|
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
||||||
|
|
@ -1281,10 +1276,10 @@ The following example will output "hello world!" on screen indefinitely:
|
||||||
with
|
with
|
||||||
----
|
----
|
||||||
|
|
||||||
`with` is used to wrap execution of a block with a context manager. The context
|
`with` is used to wrap the execution of a block within a context manager. The
|
||||||
manager can then set up the local system and tear it down in a controlled
|
context manager can then set up the local system and tear it down in a controlled
|
||||||
manner. Typical example of using `with` is processing files. `with` can bind
|
manner. The archetypical example of using `with` is when processing files. `with`
|
||||||
context to an argument or ignore it completely, as shown below:
|
can bind context to an argument or ignore it completely, as shown below:
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
||||||
|
|
@ -1306,12 +1301,12 @@ with-decorator
|
||||||
--------------
|
--------------
|
||||||
|
|
||||||
`with-decorator` is used to wrap a function with another. The function
|
`with-decorator` is used to wrap a function with another. The function
|
||||||
performing decoration should accept a single value, the function being
|
performing the decoration should accept a single value: the function being
|
||||||
decorated and return a new function. `with-decorator` takes a minimum
|
decorated, and return a new function. `with-decorator` takes a minimum
|
||||||
of two parameters, the function performing decoration and the function
|
of two parameters: the function performing decoration and the function
|
||||||
being decorated. More than one decorator function can be applied, they
|
being decorated. More than one decorator function can be applied; they
|
||||||
will be applied in order from outermost to innermost, ie. the first
|
will be applied in order from outermost to innermost, ie. the first
|
||||||
decorator will be the outermost one & so on. Decorators with arguments
|
decorator will be the outermost one, and so on. Decorators with arguments
|
||||||
are called just like a function call.
|
are called just like a function call.
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
@ -1326,11 +1321,10 @@ are called just like a function call.
|
||||||
(defn some-function [] ...)
|
(defn some-function [] ...)
|
||||||
|
|
||||||
|
|
||||||
|
In the following example, `inc-decorator` is used to decorate the function
|
||||||
In the following example, `inc-decorator` is used to decorate function
|
|
||||||
`addition` with a function that takes two parameters and calls the
|
`addition` with a function that takes two parameters and calls the
|
||||||
decorated function with values that are incremented by 1. When
|
decorated function with values that are incremented by 1. When
|
||||||
decorated `addition` is called with values 1 and 1, the end result
|
the decorated `addition` is called with values 1 and 1, the end result
|
||||||
will be 4 (1+1 + 1+1).
|
will be 4 (1+1 + 1+1).
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
@ -1356,8 +1350,7 @@ with-gensyms
|
||||||
|
|
||||||
.. versionadded:: 0.9.12
|
.. versionadded:: 0.9.12
|
||||||
|
|
||||||
`with-gensym` form is used to generate a set of :ref:`gensym` for use
|
`with-gensym` is used to generate a set of :ref:`gensym` for use in a macro.
|
||||||
in a macro.
|
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
||||||
|
|
@ -1381,11 +1374,11 @@ expands to:
|
||||||
yield
|
yield
|
||||||
-----
|
-----
|
||||||
|
|
||||||
`yield` is used to create a generator object, that returns 1 or more values.
|
`yield` is used to create a generator object that returns one or more values.
|
||||||
The generator is iterable and therefore can be used in loops, list
|
The generator is iterable and therefore can be used in loops, list
|
||||||
comprehensions and other similar constructs.
|
comprehensions and other similar constructs.
|
||||||
|
|
||||||
The function random-numbers shows how generators can be used to generate
|
The function `random-numbers` shows how generators can be used to generate
|
||||||
infinite series without consuming infinite amount of memory.
|
infinite series without consuming infinite amount of memory.
|
||||||
|
|
||||||
.. code-block:: clj
|
.. code-block:: clj
|
||||||
|
|
@ -1416,5 +1409,5 @@ yield-from
|
||||||
|
|
||||||
`yield-from` is used to call a subgenerator. This is useful if you
|
`yield-from` is used to call a subgenerator. This is useful if you
|
||||||
want your coroutine to be able to delegate its processes to another
|
want your coroutine to be able to delegate its processes to another
|
||||||
coroutine, say if using something fancy like
|
coroutine, say, if using something fancy like
|
||||||
`asyncio <http://docs.python.org/3.4/library/asyncio.html>`_.
|
`asyncio <http://docs.python.org/3.4/library/asyncio.html>`_.
|
||||||
|
|
|
||||||
|
|
@ -7,7 +7,7 @@ Command Line Interface
|
||||||
hy
|
hy
|
||||||
--
|
--
|
||||||
|
|
||||||
Command line options
|
Command Line Options
|
||||||
^^^^^^^^^^^^^^^^^^^^
|
^^^^^^^^^^^^^^^^^^^^
|
||||||
|
|
||||||
.. cmdoption:: -c <command>
|
.. cmdoption:: -c <command>
|
||||||
|
|
|
||||||
|
|
@ -1,10 +1,10 @@
|
||||||
=================
|
=======
|
||||||
Hy Core
|
Hy Core
|
||||||
=================
|
=======
|
||||||
|
|
||||||
|
|
||||||
Core Functions
|
Core Functions
|
||||||
===============
|
==============
|
||||||
|
|
||||||
.. _butlast-fn:
|
.. _butlast-fn:
|
||||||
|
|
||||||
|
|
@ -40,7 +40,7 @@ coll?
|
||||||
|
|
||||||
Usage: ``(coll? x)``
|
Usage: ``(coll? x)``
|
||||||
|
|
||||||
Returns true if argument is iterable and not a string.
|
Returns `True` if argument is iterable and not a string.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
||||||
|
|
@ -149,7 +149,7 @@ empty?
|
||||||
|
|
||||||
Usage: ``(empty? coll)``
|
Usage: ``(empty? coll)``
|
||||||
|
|
||||||
Return True if ``coll`` is empty, i.e. ``(= 0 (len coll))``.
|
Return `True` if ``coll`` is empty. Equivalent to ``(= 0 (len coll))``.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
||||||
|
|
@ -172,7 +172,8 @@ every?
|
||||||
|
|
||||||
Usage: ``(every? pred coll)``
|
Usage: ``(every? pred coll)``
|
||||||
|
|
||||||
Return True if ``(pred x)`` is logical true for every ``x`` in ``coll``, otherwise False. Return True if ``coll`` is empty.
|
Return `True` if ``(pred x)`` is logical true for every ``x`` in ``coll``,
|
||||||
|
otherwise `False`. Return `True` if ``coll`` is empty.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
||||||
|
|
@ -196,7 +197,7 @@ float?
|
||||||
|
|
||||||
Usage: ``(float? x)``
|
Usage: ``(float? x)``
|
||||||
|
|
||||||
Return True if x is a float.
|
Return `True` if x is a float.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
||||||
|
|
@ -214,7 +215,7 @@ even?
|
||||||
|
|
||||||
Usage: ``(even? x)``
|
Usage: ``(even? x)``
|
||||||
|
|
||||||
Return True if x is even.
|
Return `True` if x is even.
|
||||||
|
|
||||||
Raises ``TypeError`` if ``(not (numeric? x))``.
|
Raises ``TypeError`` if ``(not (numeric? x))``.
|
||||||
|
|
||||||
|
|
@ -278,7 +279,7 @@ instance?
|
||||||
|
|
||||||
Usage: ``(instance? CLASS x)``
|
Usage: ``(instance? CLASS x)``
|
||||||
|
|
||||||
Return True if x is an instance of CLASS.
|
Return `True` if x is an instance of CLASS.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
||||||
|
|
@ -303,7 +304,7 @@ integer?
|
||||||
|
|
||||||
Usage: ``(integer? x)``
|
Usage: ``(integer? x)``
|
||||||
|
|
||||||
Return True if x is an integer. For Python 2, this is
|
Return `True` if x is an integer. For Python 2, this is
|
||||||
either ``int`` or ``long``. For Python 3, this is ``int``.
|
either ``int`` or ``long``. For Python 3, this is ``int``.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
@ -324,7 +325,8 @@ interleave
|
||||||
|
|
||||||
Usage: ``(interleave seq1 seq2 ...)``
|
Usage: ``(interleave seq1 seq2 ...)``
|
||||||
|
|
||||||
Return an iterable of the first item in each of the sequences, then the second etc.
|
Return an iterable of the first item in each of the sequences,
|
||||||
|
then the second, etc.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
||||||
|
|
@ -362,7 +364,7 @@ iterable?
|
||||||
|
|
||||||
Usage: ``(iterable? x)``
|
Usage: ``(iterable? x)``
|
||||||
|
|
||||||
Return True if x is iterable. Iterable objects return a new iterator
|
Return `True` if x is iterable. Iterable objects return a new iterator
|
||||||
when ``(iter x)`` is called. Contrast with :ref:`iterator?-fn`.
|
when ``(iter x)`` is called. Contrast with :ref:`iterator?-fn`.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
@ -395,7 +397,7 @@ iterator?
|
||||||
|
|
||||||
Usage: ``(iterator? x)``
|
Usage: ``(iterator? x)``
|
||||||
|
|
||||||
Return True if x is an iterator. Iterators are objects that return
|
Return `True` if x is an iterator. Iterators are objects that return
|
||||||
themselves as an iterator when ``(iter x)`` is called.
|
themselves as an iterator when ``(iter x)`` is called.
|
||||||
Contrast with :ref:`iterable?-fn`.
|
Contrast with :ref:`iterable?-fn`.
|
||||||
|
|
||||||
|
|
@ -502,7 +504,7 @@ neg?
|
||||||
|
|
||||||
Usage: ``(neg? x)``
|
Usage: ``(neg? x)``
|
||||||
|
|
||||||
Return True if x is less than zero (0).
|
Return `True` if x is less than zero (0).
|
||||||
|
|
||||||
Raises ``TypeError`` if ``(not (numeric? x))``.
|
Raises ``TypeError`` if ``(not (numeric? x))``.
|
||||||
|
|
||||||
|
|
@ -521,11 +523,11 @@ Raises ``TypeError`` if ``(not (numeric? x))``.
|
||||||
.. _nil?-fn:
|
.. _nil?-fn:
|
||||||
|
|
||||||
nil?
|
nil?
|
||||||
-----
|
----
|
||||||
|
|
||||||
Usage: ``(nil? x)``
|
Usage: ``(nil? x)``
|
||||||
|
|
||||||
Return True if x is nil/None.
|
Return `True` if x is `nil`/`None`.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
||||||
|
|
@ -554,7 +556,7 @@ none?
|
||||||
|
|
||||||
Usage: ``(none? x)``
|
Usage: ``(none? x)``
|
||||||
|
|
||||||
Return True if x is None.
|
Return `True` if x is `None`.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
||||||
|
|
@ -614,7 +616,7 @@ numeric?
|
||||||
|
|
||||||
Usage: ``(numeric? x)``
|
Usage: ``(numeric? x)``
|
||||||
|
|
||||||
Return True if x is a numeric, as defined in the Python
|
Return `True` if x is a numeric, as defined in the Python
|
||||||
numbers module class ``numbers.Number``.
|
numbers module class ``numbers.Number``.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
@ -636,7 +638,7 @@ odd?
|
||||||
|
|
||||||
Usage: ``(odd? x)``
|
Usage: ``(odd? x)``
|
||||||
|
|
||||||
Return True if x is odd.
|
Return `True` if x is odd.
|
||||||
|
|
||||||
Raises ``TypeError`` if ``(not (numeric? x))``.
|
Raises ``TypeError`` if ``(not (numeric? x))``.
|
||||||
|
|
||||||
|
|
@ -659,7 +661,7 @@ pos?
|
||||||
|
|
||||||
Usage: ``(pos? x)``
|
Usage: ``(pos? x)``
|
||||||
|
|
||||||
Return True if x is greater than zero (0).
|
Return `True` if x is greater than zero (0).
|
||||||
|
|
||||||
Raises ``TypeError`` if ``(not (numeric? x))``.
|
Raises ``TypeError`` if ``(not (numeric? x))``.
|
||||||
|
|
||||||
|
|
@ -728,7 +730,7 @@ string?
|
||||||
|
|
||||||
Usage: ``(string? x)``
|
Usage: ``(string? x)``
|
||||||
|
|
||||||
Return True if x is a string.
|
Return `True` if x is a string.
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
||||||
|
|
@ -745,7 +747,7 @@ zero?
|
||||||
|
|
||||||
Usage: ``(zero? x)``
|
Usage: ``(zero? x)``
|
||||||
|
|
||||||
Return True if x is zero (0).
|
Return `True` if x is zero (0).
|
||||||
|
|
||||||
.. code-block:: hy
|
.. code-block:: hy
|
||||||
|
|
||||||
|
|
|
||||||
|
|
@ -10,7 +10,7 @@ Internal Hy Documentation
|
||||||
Hy Models
|
Hy Models
|
||||||
=========
|
=========
|
||||||
|
|
||||||
Introduction to Hy models
|
Introduction to Hy Models
|
||||||
-------------------------
|
-------------------------
|
||||||
|
|
||||||
Hy models are a very thin layer on top of regular Python objects,
|
Hy models are a very thin layer on top of regular Python objects,
|
||||||
|
|
@ -33,7 +33,7 @@ macros, be that in the compiler or in pure hy macros.
|
||||||
``HyObject`` is not intended to be used directly to instantiate Hy
|
``HyObject`` is not intended to be used directly to instantiate Hy
|
||||||
models, but only as a mixin for other classes.
|
models, but only as a mixin for other classes.
|
||||||
|
|
||||||
Compound models
|
Compound Models
|
||||||
---------------
|
---------------
|
||||||
|
|
||||||
Parenthesized and bracketed lists are parsed as compound models by the
|
Parenthesized and bracketed lists are parsed as compound models by the
|
||||||
|
|
@ -77,7 +77,7 @@ The decision of using a list instead of a dict as the base class for
|
||||||
benefit of allowing compound expressions as dict keys (as, for instance,
|
benefit of allowing compound expressions as dict keys (as, for instance,
|
||||||
the :ref:`HyExpression` Python class isn't hashable).
|
the :ref:`HyExpression` Python class isn't hashable).
|
||||||
|
|
||||||
Atomic models
|
Atomic Models
|
||||||
-------------
|
-------------
|
||||||
|
|
||||||
In the input stream, double-quoted strings, respecting the Python
|
In the input stream, double-quoted strings, respecting the Python
|
||||||
|
|
@ -115,7 +115,7 @@ strings.
|
||||||
|
|
||||||
.. _hy_numeric_models:
|
.. _hy_numeric_models:
|
||||||
|
|
||||||
Numeric models
|
Numeric Models
|
||||||
~~~~~~~~~~~~~~
|
~~~~~~~~~~~~~~
|
||||||
|
|
||||||
``hy.models.integer.HyInteger`` represents integer literals (using the
|
``hy.models.integer.HyInteger`` represents integer literals (using the
|
||||||
|
|
@ -217,7 +217,7 @@ from source to runtime.
|
||||||
|
|
||||||
.. _lexing:
|
.. _lexing:
|
||||||
|
|
||||||
Steps 1 and 2: Tokenizing and parsing
|
Steps 1 and 2: Tokenizing and Parsing
|
||||||
-------------------------------------
|
-------------------------------------
|
||||||
|
|
||||||
The first stage of compiling Hy is to lex the source into tokens that we can
|
The first stage of compiling Hy is to lex the source into tokens that we can
|
||||||
|
|
@ -238,7 +238,7 @@ on (directly), and it's what the compiler uses when it compiles Hy down.
|
||||||
|
|
||||||
.. _compiling:
|
.. _compiling:
|
||||||
|
|
||||||
Step 3: Hy compilation to Python AST
|
Step 3: Hy Compilation to Python AST
|
||||||
------------------------------------
|
------------------------------------
|
||||||
|
|
||||||
This is where most of the magic in Hy happens. This is where we take Hy AST
|
This is where most of the magic in Hy happens. This is where we take Hy AST
|
||||||
|
|
@ -262,7 +262,7 @@ All methods that preform a compilation are marked with the ``@builds()``
|
||||||
decorator. You can either pass the class of the Hy model that it compiles,
|
decorator. You can either pass the class of the Hy model that it compiles,
|
||||||
or you can use a string for expressions. I'll clear this up in a second.
|
or you can use a string for expressions. I'll clear this up in a second.
|
||||||
|
|
||||||
First stage type-dispatch
|
First Stage Type-Dispatch
|
||||||
~~~~~~~~~~~~~~~~~~~~~~~~~
|
~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||||
|
|
||||||
Let's start in the ``compile`` method. The first thing we do is check the
|
Let's start in the ``compile`` method. The first thing we do is check the
|
||||||
|
|
@ -276,14 +276,14 @@ Hy AST to Python AST. The ``compile_string`` method takes the ``HyString``, and
|
||||||
returns an ``ast.Str()`` that's populated with the correct line-numbers and
|
returns an ``ast.Str()`` that's populated with the correct line-numbers and
|
||||||
content.
|
content.
|
||||||
|
|
||||||
Macro-expand
|
Macro-Expand
|
||||||
~~~~~~~~~~~~
|
~~~~~~~~~~~~
|
||||||
|
|
||||||
If we get a ``HyExpression``, we'll attempt to see if this is a known
|
If we get a ``HyExpression``, we'll attempt to see if this is a known
|
||||||
Macro, and push to have it expanded by invoking ``hy.macros.macroexpand``, then
|
Macro, and push to have it expanded by invoking ``hy.macros.macroexpand``, then
|
||||||
push the result back into ``HyASTCompiler.compile``.
|
push the result back into ``HyASTCompiler.compile``.
|
||||||
|
|
||||||
Second stage expression-dispatch
|
Second Stage Expression-Dispatch
|
||||||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||||
|
|
||||||
The only special case is the ``HyExpression``, since we need to create different
|
The only special case is the ``HyExpression``, since we need to create different
|
||||||
|
|
@ -300,7 +300,7 @@ properly handle that case as well (most likely by raising an ``Exception``).
|
||||||
If the String isn't known to Hy, it will default to create an ``ast.Call``,
|
If the String isn't known to Hy, it will default to create an ``ast.Call``,
|
||||||
which will try to do a runtime call (in Python, something like ``foo()``).
|
which will try to do a runtime call (in Python, something like ``foo()``).
|
||||||
|
|
||||||
Issues hit with Python AST
|
Issues Hit with Python AST
|
||||||
~~~~~~~~~~~~~~~~~~~~~~~~~~
|
~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||||
|
|
||||||
Python AST is great; it's what's enabled us to write such a powerful project
|
Python AST is great; it's what's enabled us to write such a powerful project
|
||||||
|
|
@ -351,7 +351,7 @@ into::
|
||||||
By forcing things into an ``ast.expr`` if we can, but the general idea holds.
|
By forcing things into an ``ast.expr`` if we can, but the general idea holds.
|
||||||
|
|
||||||
|
|
||||||
Step 4: Python bytecode output and runtime
|
Step 4: Python Bytecode Output and Runtime
|
||||||
------------------------------------------
|
------------------------------------------
|
||||||
|
|
||||||
After we have a Python AST tree that's complete, we can try and compile it to
|
After we have a Python AST tree that's complete, we can try and compile it to
|
||||||
|
|
@ -365,8 +365,8 @@ Hy Macros
|
||||||
|
|
||||||
.. _using-gensym:
|
.. _using-gensym:
|
||||||
|
|
||||||
Using gensym for safer macros
|
Using gensym for Safer Macros
|
||||||
------------------------------
|
-----------------------------
|
||||||
|
|
||||||
When writing macros, one must be careful to avoid capturing external variables
|
When writing macros, one must be careful to avoid capturing external variables
|
||||||
or using variable names that might conflict with user code.
|
or using variable names that might conflict with user code.
|
||||||
|
|
@ -447,13 +447,13 @@ Our final version of ``nif``, built with ``defmacro/g!`` becomes:
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
Checking macro arguments and raising exceptions
|
Checking Macro Arguments and Raising Exceptions
|
||||||
-----------------------------------------------
|
-----------------------------------------------
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
Hy Compiler Builtins
|
Hy Compiler Built-Ins
|
||||||
====================
|
=====================
|
||||||
|
|
||||||
.. todo::
|
.. todo::
|
||||||
Write this.
|
Write this.
|
||||||
|
|
|
||||||
|
|
@ -6,8 +6,8 @@
|
||||||
Reader Macros
|
Reader Macros
|
||||||
=============
|
=============
|
||||||
|
|
||||||
Reader macros gives LISP the power to modify and alter syntax on the fly.
|
Reader macros gives Lisp the power to modify and alter syntax on the fly.
|
||||||
You don't want polish notation? A reader macro can easily do just that. Want
|
You don't want Polish notation? A reader macro can easily do just that. Want
|
||||||
Clojure's way of having a regex? Reader macros can also do this easily.
|
Clojure's way of having a regex? Reader macros can also do this easily.
|
||||||
|
|
||||||
|
|
||||||
|
|
@ -33,7 +33,7 @@ else. This is a problem reader macros are able to solve in a neat way.
|
||||||
=> #t(1 2 3)
|
=> #t(1 2 3)
|
||||||
(1, 2, 3)
|
(1, 2, 3)
|
||||||
|
|
||||||
You could even do like clojure, and have a literal for regular expressions!
|
You could even do it like Clojure and have a literal for regular expressions!
|
||||||
|
|
||||||
::
|
::
|
||||||
|
|
||||||
|
|
@ -46,10 +46,10 @@ You could even do like clojure, and have a literal for regular expressions!
|
||||||
Implementation
|
Implementation
|
||||||
==============
|
==============
|
||||||
|
|
||||||
``defreader`` takes a single character as symbol name for the reader macro,
|
``defreader`` takes a single character as symbol name for the reader macro;
|
||||||
anything longer will return an error. Implementation wise, ``defreader``
|
anything longer will return an error. Implementation-wise, ``defreader``
|
||||||
expands into a lambda covered with a decorator, this decorator saves the
|
expands into a lambda covered with a decorator. This decorator saves the
|
||||||
lambda in a dict with its module name and symbol.
|
lambda in a dictionary with its module name and symbol.
|
||||||
|
|
||||||
::
|
::
|
||||||
|
|
||||||
|
|
|
||||||
Loading…
Reference in New Issue
Block a user