part of shnell – a source to source compiler enhancement tool
© Jens Gustedt, 2020
A tool to emulate lambda expressions in C by means of gcc’s nested functions
This implements a rewrite of C code with lambdas to C code using gcc features
nested functions
the
__typeof__operator
This implements function literals as normal function pointers, so these should also work outside the scope where the lambda expression is evaluated.
Closures are also implemented as function pointers, but these point to a trampoline on the stack, so such a lambda value should never leave the scope of the evaluation.
This rewrite can do a lot of things, but there are still some restrictions. In particular, the lambda expression must be movable to the surrounding scope, so this may not work for lambda expressions within for-loop definitions, in a statement controlled by an if or similar where there are no scoping {}, or that are used to initialize a variable that is defined as subsequent definition after a comma.
Coding and configuration
The following code is needed to enable the sh-module framework.SRC="$_" . "${0%%/${0##*/}}/import.sh"Load the corresponding callback that prefixes a block with the definitions of its lambdas.
Imports
The following sh-modules are imported: