-
Notifications
You must be signed in to change notification settings - Fork 14
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
25 changed files
with
1,437 additions
and
153 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
157 changes: 157 additions & 0 deletions
157
ion-schema/src/main/kotlin/com/amazon/ionschema/internal/util/regex.kt
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,157 @@ | ||
| package com.amazon.ionschema.internal.util | ||
|
|
||
| import com.amazon.ionschema.InvalidSchemaException | ||
| import com.amazon.ionschema.IonSchemaVersion | ||
|
|
||
| /** | ||
| * Validates that a regex pattern is valid for the subset of ECMA-262 that is supported by Ion Schema, and converts | ||
| * to the equivalent syntax for Java Regex. | ||
| */ | ||
| internal fun validateRegexPattern(string: String, islVersion: IonSchemaVersion = IonSchemaVersion.v2_0): String { | ||
| val si = StringIterator(string) | ||
| val sb = StringBuilder() | ||
| var ch = si.next() | ||
| do { | ||
| when (ch) { | ||
| '[' -> { | ||
| sb.append(ch) | ||
| parseCharacterClass(si, sb, islVersion) | ||
| } | ||
| '(' -> { | ||
| sb.append(ch) | ||
| ch = si.next() | ||
| if (ch == '?') { // error on "(?..." constructs | ||
| error(si, "invalid character '$ch'") | ||
| } | ||
| sb.append(ch) | ||
| } | ||
| '\\' -> { // handle escaped chars | ||
| ch = si.next() | ||
| when (ch) { | ||
| '.', '^', '$', '|', '?', '*', '+', '\\', | ||
| '[', ']', '(', ')', '{', '}', | ||
| 'w', 'W', 'd', 'D' -> sb.append('\\').append(ch) | ||
| 's' -> sb.append("[ \\f\\n\\r\\t]") | ||
| 'S' -> sb.append("[^ \\f\\n\\r\\t]") | ||
| else -> error(si, "invalid escape character '$ch'") | ||
| } | ||
| } | ||
| else -> sb.append(ch) // otherwise, accept the character | ||
| } | ||
|
|
||
| parseQuantifier(si, sb) // parse a quantifier, if present | ||
|
|
||
| ch = si.next() | ||
| } while (ch != null) | ||
|
|
||
| return sb.toString() // Pattern.compile(sb.toString(), flags) | ||
| } | ||
|
|
||
| private fun parseCharacterClass(si: StringIterator, sb: StringBuilder, islVersion: IonSchemaVersion) { | ||
| do { | ||
| val ch = si.next() | ||
| sb.append(ch) | ||
|
|
||
| when (ch) { | ||
| '&' -> { | ||
| if (si.peek() == '&') { | ||
| error(si, "'&&' is not supported in a character class") | ||
| } | ||
| } | ||
|
|
||
| '[' -> error(si, "'[' must be escaped within a character class") | ||
|
|
||
| '\\' -> { | ||
| when (val ch2 = si.next()) { | ||
| '[', ']', '\\' -> sb.append(ch2) | ||
| 'd', 's', 'w', 'D', 'S', 'W' -> if (islVersion == IonSchemaVersion.v1_0) { | ||
| // For Ion Schema 1.0, this is an error because ISL 1.0 does | ||
| // not support pre-defined char classes (i.e., \d, \s, \w) | ||
| // while user is specifying a new char class | ||
| error(si, "invalid sequence '\\$ch2' in character class") | ||
| } else { | ||
| // In Ion Schema 2.0, this is allowed | ||
| sb.append(ch2) | ||
| } | ||
| else -> error( | ||
| si, | ||
| "invalid sequence '\\$ch2' in character class" | ||
| ) | ||
| } | ||
| } | ||
|
|
||
| ']' -> return | ||
| } | ||
| } while (ch != null) | ||
|
|
||
| error(si, "character class missing ']'") | ||
| } | ||
| private fun parseQuantifier(si: StringIterator, sb: StringBuilder) { | ||
| val initialLength = sb.length | ||
| var ch = si.peek() | ||
| when (ch) { | ||
| '?', '*', '+' -> { | ||
| ch = si.next() | ||
| sb.append(ch) | ||
| } | ||
| '{' -> { | ||
| ch = si.next() | ||
| sb.append(ch) | ||
| var complete = false | ||
| // A quantifier such as {,3} is not an ECMA 262 quantifier (it has no lower bound) | ||
| // We track whether we've found a number so that we can ensure that a comma is only | ||
| // allowed if it follows at least one digit. | ||
| var foundAnyNumber = false | ||
| do { | ||
| ch = si.next() | ||
| when (ch) { | ||
| '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' -> { sb.append(ch); foundAnyNumber = true } | ||
| ',' -> if (foundAnyNumber) sb.append(ch) else error(si, "range quantifier is missing lower bound") | ||
| '}' -> { | ||
| sb.append(ch) | ||
| complete = true | ||
| } | ||
| null -> {} | ||
| else -> error(si, "invalid character '$ch'") | ||
| } | ||
| } while (ch != null && !complete) | ||
|
|
||
| if (!complete) { | ||
| error(si, "range quantifier missing '}'") | ||
| } | ||
| } | ||
| } | ||
|
|
||
| if (sb.length > initialLength && ch != null) { | ||
| ch = si.peek() | ||
| when (ch) { | ||
| '?' -> error(si, "invalid character '$ch'") | ||
| '+' -> error(si, "invalid character '$ch'") | ||
| } | ||
| } | ||
| } | ||
| private fun error(si: StringIterator, message: String): Unit = | ||
| throw InvalidSchemaException("$message in regex '$si' at offset ${si.currentIndex()}") | ||
|
|
||
| private class StringIterator(private val s: String) { | ||
| private var index = -1 | ||
| val length = s.length | ||
|
|
||
| fun next(): Char? { | ||
| index += 1 | ||
| return get(index) | ||
| } | ||
|
|
||
| fun peek() = get(index + 1) | ||
|
|
||
| private fun get(i: Int): Char? { | ||
| if (i < length) { | ||
| return s[i] | ||
| } | ||
| return null | ||
| } | ||
|
|
||
| fun currentIndex() = index | ||
|
|
||
| override fun toString() = s | ||
| } |
Oops, something went wrong.