Ocaml编程代写 | CSE-112 Program 2 Interpreter in Ocaml


1. Overview

This project will repeat the Mini Basic interpreter,except this time the program will be written in Ocaml but with Mini Basic programs untranslated from the original.
See the score directory for sample input files.Output should be the same as for the Scheme version of the program, except for minor variations in output due to differences between the Scheme and Ocaml languages.Any results whichwould produce acomplex value in Scheme should produce nan in this project.

2. Running ocaml interactively

Ocaml mayberun interactively from the command line or as a compiled program.
The compiled program version, created using make is required for all submitted programs.

To run ocaml interactively,add the following to your $HOME/.bash_profile :
export PATH=$PATH:/afs/cats.ucsc.edu/courses/cse112-wm/usr/ocaml/bin
When running ocaml interactively,use the command rlwrap to gain access to the readline arrow keys so that you can recover earlier typed lines.Example :

-bash-$ rlwrap ocaml
OCaml version 4.02.1
# let f x y = x +. y;;
val f : float -> float -> float = <fun>
# f3.;;
-:float -> float = <fun>
# f3.4.;;
-:float = 7.
# ^D

To simplify typing,the following line might be added to your $HOME/.bash_profile :
alias wocaml=”rlwrap ocaml”

The suggestions above assume you are using bash as your login shell. If not, use the syntax appropriate for whatever shell you are using.

Some files that are useful when running interactively are :

Aset of #use directives whichcan be used for interactive testing of the functions.This file is not used in compilation. After starting Ocaml, type in the following command to load your source code interactively :

#use “using”;;

As an alternative to the using file,create the file .ocamlinit containing the same information. The file .ocamlinit in the current directory is automati-cally sourced when ocaml starts.

As an alternative,start up ocaml with the line

rlwrap ocaml -init using

whichwill start up the init file when needed, but avoid the automatic startup when you don’t want it. If you have a .ocamlinit and want to ocassionally suppress it,you can use

rlwrap ocaml -init /dev/null

3. Source code

The following files and modules are provided in the code/ subdirectory :
etc.mli, etc.ml

Interface and implementation of the Etc module,whichcontains miscellaneous
functions not specifically tied to other purposes.

Definition of the abstract syntax used by the interpreter.Noimplementation
file is needed.
tables.mli, tables.ml

Module for maintaining the five tables needed by the program. The interface
file is automatically generated from the implemenation, not entered manually.
The required tables and their types are :

The unary functions.
type unary_fn_table_t = (string, float -> float) Hashtbl.t

The binary functions.
type binary_fn_table_t = (string, float -> float -> float) Hashtbl.t
Because Ocaml is strongly typed, the unary and binary functions need to
be be in separate tables.

The binary functions returning boolean values.
type binary_fn_table_t = (string, float -> float -> float) Hashtbl.t
And the relational operators need to be kept in yet another function

The simple variables used by the program.
type variable_table_t = (string, float) Hashtbl.t

The arrays used by the program.
type array_table_t = (string, float array) Hashtbl.t

Labels with pointers to the list of program statements.
type label_table_t = (string, Absyn.program) Hashtbl.t