Compare two PEG grammar rules for equality. Returns Err message if the rules are different, or Ok () if they are the same.

Arguments

• expected - The expected rule to compare.
• actual - The actual rule to compare.

Returns

• Result String () - Err message if the rules are different, or Ok () if they are the same.

Example

compareRules
    (Sequence [MatchLiteral "a", MatchLiteral "b"])
    (Sequence [MatchLiteral "a", MatchLiteral "b"])
--> Ok ()


compareRules
    (Sequence [MatchLiteral "a", MatchLiteral "b"])
    (Sequence [MatchLiteral "a", MatchLiteral "c"])
--> Err "expected: MatchLiteral \"b\", actual: MatchLiteral \"c\" at position 2"

Compare two lists of PEG grammar rules for equality. Returns Err message if the rules are different, or Ok () if they are the same.

Arguments

• expected - The expected list of rules to compare.
• actual - The actual list of rules to compare.

Returns

• Result String () - Err message if the rules are different, or Ok () if they are the same.

Example

compareRuleLists
    [ Sequence [MatchLiteral "a", MatchLiteral "b"]
    , Optional (MatchLiteral "c")
    , RuleRef "foo"
    ]
    [ Sequence [MatchLiteral "a", MatchLiteral "b"]
    , Optional (MatchLiteral "c")
    , RuleRef "foo"
    ]
--> Ok ()


compareRuleLists
    [ Sequence [MatchLiteral "a", MatchLiteral "b"]
    , Optional (MatchLiteral "c")
    , RuleRef "foo"
    ]
    [ Sequence [MatchLiteral "a", MatchLiteral "b"]
    , ZeroOrMore (MatchLiteral "c")
    , RuleRef "foo"
    ]
--> Err "expected: Optional (MatchLiteral \"c\"), actual: ZeroOrMore (MatchLiteral \"c\") at position 1"