A Method for Incrementally Compiling
Languages with Nested Statement Structure
A method of incremental compilation is presented
which applies especially to programming languages 
in which statements can be nested (such as Algol and
PL/I).  The method permits editing of the source 
language using a general purpose text editor, and incremental
processing of changes without frequent 
recompilation of entire routines.  The essential points
of the method are: (1) the syntax of the language 
is restricted insof ar as which constructs may occur
on lines; (2) an internal data structure (called 
the skeleton) is maintained to represent the statement
structure; (3) the recompilation is partially 
batched in the sense that recompilation of modified lines
does not occur until the last of a set of editing 
commands has been received; and (4) the parsing and
compilation are factored into two parts, that done 
on individual lines and that done globally to
handle the relationships between the lines.
CACM December, 1972
Earley, J.
Caizergues, P.
