Keywords

Every word APML spells out, grouped by what it is for.

All of them are reserved. A keyword cannot be the name of an action, an alias, a variable, a semvar, a scope, a binding-power table, a linked module or a capture label.

node_id = "x";     # refused: 'node_id' is a reserved word
node_ident = "x";  # fine -- containing a keyword is not being one

Module & Parsers


`program`	names this module
`link`	calls into another module

Entry Point


`parser`	the block holding the start grammar

Primitive


`char`	one character, whatever it is

Built-in Functions


`spc` `nl` `eol` `eof`	space, line break, end of line, end of input

Configuration


`config`	settings for the whole grammar
`feat`	settings for one declaration

Variable


`texvar` `numvar`	declare a text or number variable

Semantic Predicate


`semvar`	a set the grammar builds and matches against
`clear`	empty a set
`scope`	a depth the input moves
`begin` `end`	a scope’s two edges
`try`	read a name as though it were already declared

Abstract Syntax Tree


`node`	a node nothing matched
`node_id`	rename what an action is saved as

Text Functions


`tex`	the namespace they live under
`order` `oneof` `icase`	any order, one of, ignoring case

Result Functions


`is` `not` `subkind`	equals, does not equal, contains
`part`	narrow to a section of what matched
`char_count` `to_num` `iter_steps`	characters, value, repetitions
`first`	the earliest member of a semvar

System Functions


`error`	stop the whole parse

Logic


`AND` `OR` `NOT`	the operators, written as words

Values


`TRUE` `FALSE`	one and zero

Units & Control


`perm`	members in any order
`until`	with a counter: repeat until this matches (`char*::until("-->")`)
`if`	branch on a test or on whether something parses
`alias`	a name for a literal value
`bindpow`	an operator precedence table
`foreign`	bind a bodiless action to your C code

Note

Nothing forces reservation. APM is scannerless, so perm only reads as a keyword before a [, and the parser could tell the two uses apart perfectly well. It is reserved because the reader is not a parser — a grammar in which part is sometimes a result function and sometimes a rule is one nobody can skim.