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reword the four steps a bit

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Nicolas Dandrimont 2014-01-02 18:09:33 +01:00
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1 changed files with 13 additions and 12 deletions
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docs/language/internals.rst
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@ -181,13 +181,14 @@ Hy Internal Theory
Overview Overview
-------- --------
The Hy internals work by acting as a front-end to Python bytecode, so that The Hy internals work by acting as a front-end to Python bytecode, so
Hy it's self compiles down to Python Bytecode, allowing an unmodified Python that Hy itself compiles down to Python Bytecode, allowing an unmodified
runtime to run Hy. Python runtime to run Hy code, without even noticing it.
The way we do this is by translating Hy into Python AST, and building that AST The way we do this is by translating Hy into an internal Python AST
down into Python bytecode using standard internals, so that we don't have datastructure, and building that AST down into Python bytecode using
to duplicate all the work of the Python internals for every single Python modules from the Python standard library, so that we don't have to
duplicate all the work of the Python internals for every single Python
release. release.
Hy works in four stages. The following sections will cover each step of Hy Hy works in four stages. The following sections will cover each step of Hy
@ -195,8 +196,8 @@ from source to runtime.
.. _lexing: .. _lexing:
Lexing / tokenizing 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
deal with. We use a project called rply, which is a really nice (and fast) deal with. We use a project called rply, which is a really nice (and fast)
@ -216,8 +217,8 @@ on (directly), and it's what the compiler uses when it compiles Hy down.
.. _compiling: .. _compiling:
Compiling 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
(the models), and compile them into Python AST. A couple of funky things happen (the models), and compile them into Python AST. A couple of funky things happen
@ -329,8 +330,8 @@ 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.
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
Python bytecode by pushing it through ``eval``. From here on out, we're no Python bytecode by pushing it through ``eval``. From here on out, we're no