Safe Haskell	Safe
Language	Haskell2010

Hpp.Expr

Description

An expression language corresponding to the subset of C syntax that may be used in preprocessor conditional directives. See https://gcc.gnu.org/onlinedocs/cpp/If.html

Synopsis

Documentation

data Expr Source

Expressions are literal values, binary operators applied to two sub-expressions, or unary operators applied to a single sub-expression.

Constructors

ELit Lit
EBinOp BinOp Expr Expr
EUnaryOp UnaryOp Expr

Instances

Eq Expr Source
Ord Expr Source
Show Expr Source

readLitInt :: String -> Maybe Int Source

Read a literal integer. These may be decimal, octal, or hexadecimal, and may have a case-insensitive suffix of u, l, or ul.

parseExpr :: [Token] -> Maybe Expr Source

Try to read an Expr from a sequence of Tokens.

renderExpr :: Expr -> String Source

Pretty-print an Expr to something semantically equivalent to the original C syntax (some parentheses may be added).

evalExpr :: Expr -> Int Source

evalExpr isDefined e evaluates expression e in an environment where the existence of macro definitions is captured by the isDefined predicate. All expressions evaluate to an Int!