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OR

Logical disjunction operator. Returns TRUE if either or both operands are TRUE.

Syntax

expression1 OR expression2
expression1 || expression2

Truth Table

A B A OR B
TRUE TRUE TRUE
TRUE FALSE TRUE
FALSE TRUE TRUE
FALSE FALSE FALSE

Examples

Example file:

-- OR keyword examples

-- Basic OR Operations

#EVAL TRUE OR TRUE
#EVAL TRUE OR FALSE
#EVAL FALSE OR TRUE
#EVAL FALSE OR FALSE

-- Symbolic Alternative (||)

#EVAL TRUE || TRUE
#EVAL TRUE || FALSE

-- In Conditional Logic

ASSUME isStudent IS A BOOLEAN
ASSUME isSenior IS A BOOLEAN

DECIDE getsDiscount IS isStudent OR isSenior

#CHECK getsDiscount

-- Chaining Multiple Conditions

GIVEN a IS A BOOLEAN
      b IS A BOOLEAN
      c IS A BOOLEAN
anyTrue a b c MEANS a OR b OR c

#EVAL anyTrue FALSE FALSE FALSE
#EVAL anyTrue FALSE TRUE FALSE

-- Layout-Sensitive OR (Vertical Format)

ASSUME isAdmin IS A BOOLEAN
ASSUME isOwner IS A BOOLEAN
ASSUME hasPermission IS A BOOLEAN

DECIDE hasAccess IS
      isAdmin
  OR  isOwner
  OR  hasPermission

#CHECK hasAccess

-- Complex Expressions with OR

GIVEN status IS A STRING
isTerminalStatus status MEANS
      status EQUALS "completed"
  OR  status EQUALS "cancelled"
  OR  status EQUALS "failed"

#EVAL isTerminalStatus "completed"
#EVAL isTerminalStatus "pending"

-- OR in IF Expressions

GIVEN userType IS A STRING, hasVIP IS A BOOLEAN
getPriority userType hasVIP MEANS
  IF userType EQUALS "admin" OR hasVIP
  THEN "high"
  ELSE "normal"

#EVAL getPriority "user" TRUE
#EVAL getPriority "user" FALSE

-- Combining AND and OR

GIVEN x IS A NUMBER, y IS A BOOLEAN
complexCondition x y MEANS
  (x > 0 AND x < 100) OR y

#EVAL complexCondition 50 FALSE
#EVAL complexCondition 150 FALSE
#EVAL complexCondition 150 TRUE

Asyndetic OR

Implicit operators using punctuation.

Double dots (..) - Implicit OR

Example:

-- Example: Asyndetic operators (... and ..)
-- Implicit AND and OR using punctuation

citizen MEANS TRUE
over18 MEANS TRUE
hasID MEANS TRUE

approved MEANS TRUE
pending MEANS FALSE
review MEANS FALSE

-- Ellipsis (...) = implicit AND
eligible1 MEANS citizen ... over18 ... hasID
-- Equivalent to: (citizen AND over18 AND hasID)

-- Double dot (..) = implicit OR
inProgress MEANS approved .. pending .. review
-- Equivalent to: (approved OR pending OR review)

#EVAL eligible1
#EVAL inProgress

Short-Circuit Evaluation

OR evaluates lazily - if the first operand is TRUE, the second is not evaluated.

  • AND - Logical conjunction
  • NOT - Logical negation
  • IMPLIES - Logical implication

See Also