class LexEngine
package hxparse
LexEngine handles pattern parsing and state transformation.
This class is used by the Lexer and rarely has to be interacted with
directly.
The static parse method transforms a single String to a Pattern.
Multiple patterns can then be passed to the constructor to generate the
state machine, which is obtainable from the firstState method.
Constructor
new (patterns:Array<Pattern>)
Creates a new LexEngine from patterns.
Each LexEngine maintains a state machine, whose initial state can be
obtained from the firstState method. After this, this LexEngine can
be discarded.
If patterns is null, the result is unspecified.
Methods
Static methods
staticparse (pattern:String):Pattern
Parses the pattern String and returns an instance of Pattern.
If pattern is not a valid pattern string, an exception of String is
thrown.
The following meta characters are supported:
- `*`: zero or more
- `+`: one or more
- `?`: zero or one
- `|`: or
- `[`: begin char range
- `]`: end char range
- `(`: begin group
- `)`: end group
- `\`: escape next char
These characters must be escaped if they are part of the pattern, by
using \\*, \\] etc.