ASTs留学生代写、代做Java，c++编程设计、Python语言代写、programs代做

日期：2019-12-23 08:52

Assessed Exercise 2, Task 1

Implement the part of the language in black. No need to implement code generation for the red

parts. No test for this task will feature programs containing language constructs in red. Your code

generator can throw CodegenException for the ASTs that correspond to language constructs in

red, or you can return RISC-V code, it does not matter.

PROG → DEC | DEC; PROG

DEC → def ID (VARDEC) = E

VARDEC → ε | VARDECNE

VARDECNE → ID | VARDECNE, ID

ID → ... (identifiers)

INT → ... (Integers)

E → INT

| ID

| if E COMP E then E else E endif

| (E BINOP E)

| (E)

| ID(ARGS)

| skip

| (E; E)

| while E COMP E do E endwhile

| repeat E until E COMP E endrepeat

| ID := E

| break

| continue

ARGS → ε | ARGSNE

ARGSNE → E | ARGSNE, E

COMP → == | < | > | <= | >=

BINOP → + | - | * | /

Recall that the relevant definitions are here, here and here (and in the Zip file / Github given on the

parent page). If you don't want to implement a feature, simply throw CodegenException when

the code generator encounters this feature.

Note that the translation of procedure invocation (given by the production E → ID(ARGS) in the

grammar above) is part of Task 1. Since every program will have at least one procedure invocation,

I strongly suggest that you focus on getting this right.