Support an external list of terms in term list operators

1 files changed, 204 insertions, 0 deletions

diff --git a/container-search/src/main/java/com/yahoo/search/yql/ParameterListParser.java b/container-search/src/main/java/com/yahoo/search/yql/ParameterListParser.java
new file mode 100644
index 00000000000..5a609f0025b
--- /dev/null
+++ b/container-search/src/main/java/com/yahoo/search/yql/ParameterListParser.java
@@ -0,0 +1,204 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.search.yql;
+
+import com.yahoo.prelude.query.WeightedSetItem;
+
+import java.util.Arrays;
+
+/**
+ * Parser of parameter lists on the form {key:value, key:value} or [[key,value], [key,value], ...]
+ *
+ * @author bratseth
+ */
+class ParameterListParser {
+
+    public static void addItemsFromString(String string, WeightedSetItem out) {
+        var s = new ParsableString(string);
+        switch (s.peek()) {
+            case '[' : addArrayItems(s, out); break;
+            case '{' : addMapItems(s, out); break;
+            default : throw new IllegalArgumentException("Expected a string starting by '[' or '{', " +
+                                                         "but was '" + s.peek() + "'");
+        }
+    }
+
+    private static void addArrayItems(ParsableString s, WeightedSetItem out) {
+        s.pass('[');
+        while (s.peek() != ']') {
+            s.pass('[');
+            long key = s.longTo(s.position(','));
+            s.pass(',');
+            int value = s.intTo(s.position(']'));
+            s.pass(']');
+            out.addToken(key, value);
+            s.passOptional(',');
+            if (s.atEnd()) throw new IllegalArgumentException("Expected an array ending by ']'");
+        }
+        s.pass(']');
+    }
+
+    private static void addMapItems(ParsableString s, WeightedSetItem out) {
+        s.pass('{');
+        while (s.peek() != '}') {
+            String key;
+            if (s.passOptional('\'')) {
+                key = s.stringTo(s.position('\''));
+                s.pass('\'');
+            }
+            else if (s.passOptional('"')) {
+                key = s.stringTo(s.position('"'));
+                s.pass('"');
+            }
+            else {
+                key = s.stringTo(s.position(':')).trim();
+            }
+            s.pass(':');
+            int value = s.intTo(s.position(',','}'));
+            out.addToken(key, value);
+            s.passOptional(',');
+            if (s.atEnd()) throw new IllegalArgumentException("Expected a map ending by '}'");
+        }
+        s.pass('}');
+    }
+
+    private static class ParsableString {
+
+        int position = 0;
+        String s;
+
+        ParsableString(String s) {
+            this.s = s;
+        }
+
+        /**
+         * Returns the next non-space character or UNASSIGNED if we have reached the end of the string.
+         * The current position is not changed.
+         */
+        char peek() {
+            int localPosition = position;
+            while (localPosition < s.length()) {
+                char nextChar = s.charAt(localPosition++);
+                if (!Character.isSpaceChar(nextChar))
+                    return nextChar;
+            }
+            return Character.UNASSIGNED;
+        }
+
+        /**
+         * Verifies that the next non-space character is the given and moves the position past it.
+         *
+         * @throws IllegalArgumentException if the next non-space character is not the given character
+         */
+        void pass(char character) {
+            while (position < s.length()) {
+                char nextChar = s.charAt(position++);
+                if (!Character.isSpaceChar(nextChar)) {
+                    if (nextChar == character)
+                        return;
+                    else
+                        throw new IllegalArgumentException("Expected '" + character + "' at position " + (position-1) +
+                                                           " but got '" + nextChar + "'");
+                }
+            }
+            throw new IllegalArgumentException("Expected '" + character + "' at position " + (position-1) +
+                                               " but reached the end");
+        }
+
+        /**
+         * Checks if the next non-space character is the given and moves the position past it if so.
+         * Does not change the position otherwise.
+         *
+         * @return true if the next non-space character was the given character
+         */
+        boolean passOptional(char character) {
+            int localPosition = position;
+            while (localPosition < s.length()) {
+                char nextChar = s.charAt(localPosition++);
+                if (!Character.isSpaceChar(nextChar)) {
+                    if (nextChar == character) {
+                        position = localPosition;
+                        return true;
+                    } else {
+                        return false;
+                    }
+                }
+            }
+            return false;
+        }
+
+        /**
+         * Returns the position of the next occurrence of any of the given characters.
+         *
+         * @throws IllegalArgumentException if there are no further occurrences of any of the given characters
+         */
+        int position(char ... characters) {
+            int localPosition = position;
+            while (localPosition < s.length()) {
+                char nextChar = s.charAt(localPosition);
+                for (char character : characters)
+                    if (nextChar == character) return localPosition;
+                localPosition++;
+            }
+            throw new IllegalArgumentException("Expected one of " + Arrays.toString(characters) + " after " + position);
+        }
+
+        boolean atEnd() {
+            return position >= s.length();
+        }
+
+        /**
+         * Returns the string value from the current to the given position, and moves the current
+         * position to the next character.
+         *
+         * @throws IllegalArgumentException if end is beyond the last position of the string
+         */
+        String stringTo(int end) {
+            try {
+                String value = s.substring(position, end);
+                position = end;
+                return value;
+            }
+            catch (IndexOutOfBoundsException e) {
+                throw new IllegalArgumentException(end + " is larger than the size of the string,  " + s.length());
+            }
+        }
+
+        /**
+         * Returns the int value from the current to the given position, and moves the current
+         * position to the next character.
+         *
+         * @throws IllegalArgumentException if the string cannot be parsed to an int or end is larger than the string
+         */
+        int intTo(int end) {
+            int start = position;
+            String value = stringTo(end);
+            try {
+                return Integer.parseInt(value.trim());
+            }
+            catch (NumberFormatException e) {
+                throw new IllegalArgumentException("Expected an integer between positions " + start + " and " + end +
+                                                   ", but got " + value);
+            }
+        }
+
+        /**
+         * Returns the long value from the current to the given position, and moves the current
+         * position to the next character.
+         *
+         * @throws IllegalArgumentException if the string cannot be parsed to a long or end is larger than the string
+         */
+        long longTo(int end) {
+            int start = position;
+            String value = stringTo(end);
+            try {
+                return Long.parseLong(value.trim());
+            }
+            catch (NumberFormatException e) {
+                throw new IllegalArgumentException("Expected an integer between positions " + start + " and " + end +
+                                                   ", but got " + value);
+            }
+        }
+
+    }
+
+}