A value that can be read from the Lua stack.

Try to convert the value at the given stack index to a Haskell value. Returns Left with an error message on failure.

WARNING: this is not save to use with custom error handling!

Read a table into a list

Read a table into a list of pairs.

Get a value by retrieving a String from Lua, then using readMaybe to convert the String into a Haskell value.

Retrieve Haskell data which was pushed to Lua as userdata.

A value that can be pushed to the Lua stack.

Push list as numerically indexed table.

Push data by wrapping it into a userdata object.

Type of raw Haskell functions that can be made into CFunctions.

Haskell function that can be called from Lua.

Operations and functions that can be pushed to the Lua stack. This is a helper function not intended to be used directly. Use the toHaskellFunction wrapper instead.

Convert a Haskell function to Lua function. Any Haskell function can be converted provided that:

• all arguments are instances of Peekable
• return type is Lua a, where a is an instance of Pushable

Any Exception will be converted to a string and returned as Lua error.

Important: this does not catch exceptions other than Exception; exception handling must be done by the converted Haskell function. Failure to do so will cause the program to crash.

E.g., the following code could be used to handle an Exception of type FooException, if that type is an instance of MonadCatch and Pushable:

toHaskellFunction (myFun `catchM` (\e -> raiseError (e :: FooException)))

Call a Lua function. Use as:

v <- callfunc "proc" "abc" (1::Int) (5.0::Double)

Create new foreign Lua function. Function created can be called by the Lua engine. Remeber to free the pointer with freecfunction.

Free function pointer created with newcfunction.

Pushes Haskell function as a callable userdata. All values created will be garbage collected. Use as:

pushHaskellFunction myfun
setglobal "myfun"

Error conditions should be indicated by raising a Lua Exception or by returning the result of error.

Imports a Haskell function and registers it at global name.

Run Lua computation using the default HsLua state as starting point. Exceptions are masked, thus avoiding some issues when using multiple threads. All exceptions are passed through; error handling is the responsibility of the caller.

Run Lua computation using the default HsLua state as starting point. Conversion from Lua errors to Haskell exceptions can be controlled through ErrorConversion.

Run the given Lua computation; exceptions raised in haskell code are caught, but other exceptions (user exceptions raised in haskell, unchecked type errors, etc.) are passed through.

Run Lua computation with the given Lua state and the default error-to-exception converter (throwTopStringAsException). Exception handling is left to the caller.

Like getglobal, but knows about packages and nested tables. E.g.

getglobal' "math.sin"

will return the function sin in package math.

Like setglobal, but knows about packages and nested tables. E.g.

pushstring "0.9.4"
setglobal' "mypackage.version"

All tables and fields, except for the last field, must exist.

Raise a Lua error, using the given value as the error object.

Newtype wrapper intended to be used for optional Lua values. Nesting this type is strongly discouraged as missing values on inner levels are indistinguishable from missing values on an outer level; wrong values would be the likely result.

Get, then pop the value at the top of the stack. The pop operation is executed even if the retrieval operation failed.

Load a module, defined by a Haskell action, under the given name.

Similar to luaL_required: After checking "loaded" table, calls pushMod to push a module to the stack, and registers the result in package.loaded table.

The pushMod function must push exactly one element to the top of the stack. This is not checked, but failure to do so will lead to problems. Lua's package module must have been loaded by the time this function is invoked.

Leaves a copy of the module on the stack.

Registers a preloading function. Takes an module name and the Lua operation which produces the package.

Create a new module (i.e., a Lua table).

Add a string-indexed field to the table at the top of the stack.

Attach a function to the table at the top of the stack, using the given name.