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Diffstat (limited to 'docs/users_guide/ghci.rst')
| -rw-r--r-- | docs/users_guide/ghci.rst | 46 |
1 files changed, 43 insertions, 3 deletions
diff --git a/docs/users_guide/ghci.rst b/docs/users_guide/ghci.rst index 390719ff80..9f63e0c50b 100644 --- a/docs/users_guide/ghci.rst +++ b/docs/users_guide/ghci.rst @@ -1520,12 +1520,52 @@ breakpoint is to name a top-level function: .. code-block:: none - :break identifier + :break identifier Where ⟨identifier⟩ names any top-level function in an interpreted module currently loaded into GHCi (qualified names may be used). The breakpoint -will be set on the body of the function, when it is fully applied but -before any pattern matching has taken place. +will be set on the body of the function, when it is fully applied. +If the function has several patterns, then a breakpoint will be set on +each of them. + +By using qualified names, one can set breakpoints on all functions +(top-level and nested) in every loaded and interpreted module: + +.. code-block:: none + + :break [ModQual.]topLevelIdent[.nestedIdent]...[.nestedIdent] + +⟨ModQual⟩ is optional and is either the effective name of a module or +the local alias of a qualified import statement. + +⟨topLevelIdent⟩ is the name of a top level function in the module +referenced by ⟨ModQual⟩. + +⟨nestedIdent⟩ is optional and the name of a function nested in a let or +where clause inside the previously mentioned function ⟨nestedIdent⟩ or +⟨topLevelIdent⟩. + +If ⟨ModQual⟩ is a module name, then ⟨topLevelIdent⟩ can be any top level +identifier in this module. If ⟨ModQual⟩ is missing or a local alias of a +qualified import, then ⟨topLevelIdent⟩ must be in scope. + +Breakpoints can be set on arbitrarily deeply nested functions, but the +whole chain of nested function names must be specified. + +Consider the function ``foo`` in a module ``Main``: + +.. code-block:: none + + foo s = 'a' : add s + where add = (++"z") + +The breakpoint on the function ``add`` can be set with one of the +following commands: + +.. code-block:: none + + :break Main.foo.add + :break foo.add Breakpoints can also be set by line (and optionally column) number: |