/* Title: Pure/General/symbol.scala
ID: $Id$
Author: Makarius
Detecting and recoding Isabelle symbols.
*/
package isabelle
import java.util.regex.Pattern
import java.io.File
import scala.io.Source
import scala.collection.jcl.HashMap
object Symbol {
/** Symbol regexps **/
private def compile(s: String) =
Pattern.compile(s, Pattern.COMMENTS | Pattern.DOTALL)
private val plain_pattern = compile(""" [^\\ \ud800-\udfff] | [\ud800-\udbff][\udc00-\udfff] """)
private val symbol_pattern = compile(""" \\ \\? < (?:
\^? [A-Za-z][A-Za-z0-9_']* |
\^raw: [\x20-\x7e\u0100-\uffff && [^.>]]* ) >""")
private val bad_symbol_pattern = compile("(?!" + symbol_pattern + ")" +
""" \\ \\? < (?: (?! \s | [\"`\\] | \(\* | \*\) | \{\* | \*\} ) . )*""")
// total pattern
val pattern = compile(plain_pattern + "|" + symbol_pattern + "|" + bad_symbol_pattern + "| .")
/** Recoding **/
private class Recoder(list: List[(String, String)]) {
private val (min, max) = {
var min = '\uffff'
var max = '\u0000'
for ((x, _) <- list) {
val c = x(0)
if (c < min) min = c
if (c > max) max = c
}
(min, max)
}
private val table = {
val table = new HashMap[String, String]
for ((x, y) <- list) table + (x -> y)
table
}
def recode(text: String) = {
val len = text.length
val matcher = pattern.matcher(text)
val result = new StringBuilder(len)
var i = 0
while (i < len) {
val c = text(i)
if (min <= c && c <= max) {
matcher.region(i, len)
matcher.lookingAt
val x = matcher.group
table.get(x) match {
case Some(y) => result.append(y)
case None => result.append(x)
}
i = matcher.end
}
else { result.append(c); i += 1 }
}
result.toString
}
}
/** Symbol interpretation **/
class Interpretation {
private var symbols = new HashMap[String, HashMap[String, String]]
private var decoder: Recoder = null
private var encoder: Recoder = null
def decode(text: String) = decoder.recode(text)
def encode(text: String) = encoder.recode(text)
/* read symbols */
private val empty_pattern = compile(""" ^\s* (?: \#.* )? $ """)
private val blank_pattern = compile(""" \s+ """)
private val key_pattern = compile(""" (.+): """)
private def read_line(line: String) = {
def err() = error("Bad symbol specification (line " + line + ")")
def read_props(props: List[String], tab: HashMap[String, String]): Unit = {
props match {
case Nil => ()
case _ :: Nil => err()
case key :: value :: rest => {
val key_matcher = key_pattern.matcher(key)
if (key_matcher.matches) {
tab + (key_matcher.group(1) -> value)
read_props(rest, tab)
}
else err ()
}
}
}
if (!empty_pattern.matcher(line).matches) {
blank_pattern.split(line).toList match {
case Nil => err()
case symbol :: props => {
val tab = new HashMap[String, String]
read_props(props, tab)
symbols + (symbol -> tab)
}
}
}
}
private def read_symbols(path: String) = {
val file = new File(IsabelleSystem.platform_path(path))
if (file.canRead) {
for (line <- Source.fromFile(file).getLines) read_line(line)
}
}
/* init tables */
private def get_code(entry: (String, HashMap[String, String])) = {
val (symbol, props) = entry
val code =
try { Integer.decode(props("code")).intValue }
catch {
case _: NoSuchElementException => error("Missing code for symbol " + symbol)
case _: NumberFormatException => error("Bad code for symbol " + symbol)
}
(symbol, new String(Character.toChars(code)))
}
private def init_recoders() = {
val list = symbols.elements.toList.map(get_code)
decoder = new Recoder(list ++ (for ((x, y) <- list) yield ("\\" + x, y)))
encoder = new Recoder(for ((x, y) <- list) yield (y, x))
}
/* constructor */
read_symbols("$ISABELLE_HOME/etc/symbols")
read_symbols("$ISABELLE_HOME_USER/etc/symbols")
init_recoders()
}
}