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| -rw-r--r-- | Doc/faq/design.rst | 10 | ||||
| -rw-r--r-- | Doc/reference/compound_stmts.rst | 10 | ||||
| -rw-r--r-- | Doc/reference/expressions.rst | 13 | ||||
| -rw-r--r-- | Doc/tutorial/controlflow.rst | 2 |
4 files changed, 18 insertions, 17 deletions
diff --git a/Doc/faq/design.rst b/Doc/faq/design.rst index 724eecf..0f1c558 100644 --- a/Doc/faq/design.rst +++ b/Doc/faq/design.rst @@ -347,20 +347,20 @@ Answer 2: Fortunately, there is `Stackless Python <http://www.stackless.com>`_, which has a completely redesigned interpreter loop that avoids the C stack. -Why can't lambda forms contain statements? ------------------------------------------- +Why can't lambda expressions contain statements? +------------------------------------------------ -Python lambda forms cannot contain statements because Python's syntactic +Python lambda expressions cannot contain statements because Python's syntactic framework can't handle statements nested inside expressions. However, in Python, this is not a serious problem. Unlike lambda forms in other languages, where they add functionality, Python lambdas are only a shorthand notation if you're too lazy to define a function. Functions are already first class objects in Python, and can be declared in a -local scope. Therefore the only advantage of using a lambda form instead of a +local scope. Therefore the only advantage of using a lambda instead of a locally-defined function is that you don't need to invent a name for the function -- but that's just a local variable to which the function object (which -is exactly the same type of object that a lambda form yields) is assigned! +is exactly the same type of object that a lambda expression yields) is assigned! Can Python be compiled to machine code, C or some other language? diff --git a/Doc/reference/compound_stmts.rst b/Doc/reference/compound_stmts.rst index d0d0646..8afc69e 100644 --- a/Doc/reference/compound_stmts.rst +++ b/Doc/reference/compound_stmts.rst @@ -535,17 +535,17 @@ function. The annotation values are available as values of a dictionary keyed by the parameters' names in the :attr:`__annotations__` attribute of the function object. -.. index:: pair: lambda; form +.. index:: pair: lambda; expression It is also possible to create anonymous functions (functions not bound to a -name), for immediate use in expressions. This uses lambda forms, described in -section :ref:`lambda`. Note that the lambda form is merely a shorthand for a +name), for immediate use in expressions. This uses lambda expressions, described in +section :ref:`lambda`. Note that the lambda expression is merely a shorthand for a simplified function definition; a function defined in a ":keyword:`def`" statement can be passed around or assigned to another name just like a function -defined by a lambda form. The ":keyword:`def`" form is actually more powerful +defined by a lambda expression. The ":keyword:`def`" form is actually more powerful since it allows the execution of multiple statements and annotations. -**Programmer's note:** Functions are first-class objects. A "``def``" form +**Programmer's note:** Functions are first-class objects. A "``def``" statement executed inside a function definition defines a local function that can be returned or passed around. Free variables used in the nested function can access the local variables of the function containing the def. See section diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst index c0132bd..87a6d2e 100644 --- a/Doc/reference/expressions.rst +++ b/Doc/reference/expressions.rst @@ -1218,8 +1218,8 @@ Conditional expressions .. productionlist:: conditional_expression: `or_test` ["if" `or_test` "else" `expression`] - expression: `conditional_expression` | `lambda_form` - expression_nocond: `or_test` | `lambda_form_nocond` + expression: `conditional_expression` | `lambda_expr` + expression_nocond: `or_test` | `lambda_expr_nocond` Conditional expressions (sometimes called a "ternary operator") have the lowest priority of all Python operations. @@ -1243,10 +1243,10 @@ Lambdas pair: anonymous; function .. productionlist:: - lambda_form: "lambda" [`parameter_list`]: `expression` - lambda_form_nocond: "lambda" [`parameter_list`]: `expression_nocond` + lambda_expr: "lambda" [`parameter_list`]: `expression` + lambda_expr_nocond: "lambda" [`parameter_list`]: `expression_nocond` -Lambda forms (lambda expressions) have the same syntactic position as +Lambda expressions (sometimes called lambda forms) have the same syntactic position as expressions. They are a shorthand to create anonymous functions; the expression ``lambda arguments: expression`` yields a function object. The unnamed object behaves like a function object defined with :: @@ -1255,7 +1255,8 @@ behaves like a function object defined with :: return expression See section :ref:`function` for the syntax of parameter lists. Note that -functions created with lambda forms cannot contain statements or annotations. +functions created with lambda expressions cannot contain statements or +annotations. .. _exprlists: diff --git a/Doc/tutorial/controlflow.rst b/Doc/tutorial/controlflow.rst index 56df73d..52e382e 100644 --- a/Doc/tutorial/controlflow.rst +++ b/Doc/tutorial/controlflow.rst @@ -588,7 +588,7 @@ Lambda Expressions Small anonymous functions can be created with the :keyword:`lambda` keyword. This function returns the sum of its two arguments: ``lambda a, b: a+b``. -Lambda forms can be used wherever function objects are required. They are +Lambda functions can be used wherever function objects are required. They are syntactically restricted to a single expression. Semantically, they are just syntactic sugar for a normal function definition. Like nested function definitions, lambda functions can reference variables from the containing |