ALS Syntax

A small document on ALS syntax.

Rule

A rule is a single statement in ALS.
A rule is defined by the following pattern: short -> long - The rule above means: expand short into long. - It's equivalent to alias "short=long"

A transformation is an action performed on an ALS file.
It's defined by the following pattern: filename --> pattern - For each line of filename, transform it according to the pattern. - Every occurrence of $$ in the pattern is replaced with the long part of the rule - Example: ./dir.als --> cd $$ - Transforms foo -> bar into foo -> cd bar
All transformations are recursive. The output of one transformation becomes the $$ of the ones above it on the recursion stack.

The global pattern is the output format specified when invoking genalias2
The default pattern is alias "$<=$$", which generates standard shell aliases.
Any occurrence of $< in the pattern is replaced with the short part of the rule
Any occurrence of $$ in the pattern is replaced with the long part of the rule

Comments in ALS begin with #
Comments can be placed anywhere in the file, including after statements
An ALS statement must be contained in a single line
Empty lines and lines containing only whitespace are ignored.
IMPORTANT: Whitespace is required around the arrows (-> and -->) - foo -> bar is fine, same as foo -> bar, but foo-> bar is not, same with foo ->bar and foo-->bar - Both spaces and tabs can be used here - Additional whitespace (like alignment) is ignored