&& and || operators for CI Pipeline expressions.

Refactored regex pattern matching to eagerly return tokens

Packaged behind a default-enabled feature flag and added operator documentation.

1 files changed, 20 insertions, 0 deletions

diff --git a/lib/gitlab/ci/pipeline/expression/lexeme/operator.rb b/lib/gitlab/ci/pipeline/expression/lexeme/operator.rb
index 3ebceb92eb7..3ddab7800c8 100644
--- a/lib/gitlab/ci/pipeline/expression/lexeme/operator.rb
+++ b/lib/gitlab/ci/pipeline/expression/lexeme/operator.rb
@@ -6,9 +6,29 @@ module Gitlab
       module Expression
         module Lexeme
           class Operator < Lexeme::Base
+            # This operator class is design to handle single operators that take two
+            # arguments. Expression::Parser was originally designed to read infix operators,
+            # and so the two operands are called "left" and "right" here. If we wish to
+            # implement an Operator that takes a greater or lesser number of arguments, a
+            # structural change or additional Operator superclass will likely be needed.
+
+            OperatorError = Class.new(Expression::ExpressionError)
+
+            def initialize(left, right)
+              raise OperatorError, 'Invalid left operand' unless left.respond_to? :evaluate
+              raise OperatorError, 'Invalid right operand' unless right.respond_to? :evaluate
+
+              @left = left
+              @right = right
+            end
+
             def self.type
               :operator
             end
+
+            def self.precedence
+              raise NotImplementedError
+            end
           end
         end
       end