The SExp structure

The SExp structure defines the tree representation of S-expression data.

Synopsis

structure SExp

Interface

datatype value
  = SYMBOL of Atom.atom
  | BOOL of bool
  | INT of IntInf.int
  | FLOAT of real
  | STRING of string
  | QUOTE of value
  | LIST of value list

val same : value * value -> bool
val compare : value * value -> order

Description

datatype value = …​

This datatype represents S-expression trees. The constuctors are defined as follows:

SYMBOL of Atom.atom

represents an identifier. We use the atom type to represent these for fast equality testing.

BOOL of bool

represents a boolean literal.

INT of IntInf.int

represents an integer number.

FLOAT of real

represents a floating-point number.

STRING of string

represents a string value.

QUOTE of value list

represents a quoted value.

LIST of value list

represents a list of values.

val same : value * value -> bool

same (se1, se2) compares se1 and se2 for equality and returns true if, and only if, they are equal.

val compares : value * value -> order

same (se1, se2) compares se1 and se2 for their order.

See Also

SExpParser, SExpPP, SExpPrinter, The SExp Library