Fix typos

README.md

@@ -45,7 +45,7 @@ We assume below that all the Ada dependencies are installed under the
   ``GPR_PROJECT_PATH``, for example).
 
 * The dynamic linker has access to shared libraries (``$PREFIX/lib`` is in
-  ``LD_LIBRARY_PATH``, for exmaple).
+  ``LD_LIBRARY_PATH``, for example).
 
 First, clone the `adasat` repository in the `langkit` subdirectory of the
 `langkit` repository:

doc/lexical_envs.rst

@@ -309,7 +309,7 @@ Env specs must use another mechanism to create such cross-unit links: named
 environments. When creating an environment, one can pass a list of names
 (symbols) to ``add_env`` to associate this new environment to each name. It is
 then possible to refer to this environment from the PLE of other units thanks
-so these names:
+to these names:
 
 * If the ``AddToEnvDestEnv`` struct passed to ``add_to_env``/``add_to_env_kv``
   contains an env name, that name is used to fetch the corresponding named

doc/tutorial.rst

@@ -246,7 +246,7 @@ right you have what should be done with it:
 Only exact input strings trigger ``Literal`` matchers while the input is
 matched against a regular expression with ``Pattern`` matchers. Note that the
 order of rules is meaningful: here, the input is matched first against keywords
-and then only if there is no match, identifers and number patterns are matched.
+and then only if there is no match, identifiers and number patterns are matched.
 If ``Literal`` rules appeared at the end, ``def`` would always be emitted
 as an identifier.
 
@@ -436,7 +436,7 @@ colon.
 
     extern_decl=ExternDecl('extern', G.prototype),
 
-This one is interesting: inside the parens, we matches the ``extern`` keyword
+This one is interesting: inside the parens, we match the ``extern`` keyword
 followed by what the ``prototype`` rule matches. Then, thanks to the
 ``ExternDecl`` call, we take the content we matched and create an
 ``ExternDecl`` AST node to hold the result.