Statement lang

---

Given the DSL example source:

Show *Q2 when Q1.A1 == true
Hide *Q3 when Q1.A3 == false
Set *Q5.A1 to 3
Set *Q5.A2 to Q3.A2
Set *Q5.A3 to 10 when Q5.A2 == Q5.A1
Set *Q5.A3 to 10 when Q5.A2 == Q5.A1 and Q5.A3 == Q5.A4 or Q5.A6 == Q5.A8

The following statements will be parsed:

Statement(List(Show, Pointer(Q2), When, Val(Q1.A1), Eq, Val(true)))
Statement(List(Hide, Pointer(Q3), When, Val(Q1.A3), Eq, Val(false)))
Statement(List(Set, Pointer(Q5.A1), To, Val(3)))
Statement(List(Set, Pointer(Q5.A2), To, Val(Q3.A2)))
Statement(List(Set, Pointer(Q5.A3), To, Val(10), When, Val(Q5.A2), Eq, Val(Q5.A1)))
Statement(List(Set, Pointer(Q5.A3), To, Val(10), When, Val(Q5.A2), Eq, Val(Q5.A1), And, Val(Q5.A3), Eq, Val(Q5.A4), Or, Val(Q5.A6), Eq, Val(Q5.A8)))

Which can be translated in the following AST:

Predicate(Show(Pointer(Q2)),Eq(Value(Q1.A1),Value(true)))
Predicate(Hide(Pointer(Q3)),Eq(Value(Q1.A3),Value(false)))
Assignment(Pointer(Q5.A1),Value(3))
Assignment(Pointer(Q5.A2),Value(Q3.A2))
Predicate(Assignment(Pointer(Q5.A3),Value(10)),Eq(Value(Q5.A2),Value(Q5.A1)))
Predicate(Assignment(Pointer(Q5.A3),Value(10)),And(Eq(Value(Q5.A2),Value(Q5.A1)),Or(Eq(Value(Q5.A3),Value(Q5.A4)),Eq(Value(Q5.A6),Value(Q5.A8)))))

And, for example, can be interpreted as series of text statements

if (Q1.A1 == true) then Show *Q2
if (Q1.A3 == false) then Hide *Q3
*Q5.A1 = 3
*Q5.A2 = Q3.A2
if (Q5.A2 == Q5.A1) then *Q5.A3 = 10
if (Q5.A2 == Q5.A1 and Q5.A3 == Q5.A4 or Q5.A6 == Q5.A8) then *Q5.A3 = 10

Example of interpretation into GraphVis:

PREDICATE0 [label="PREDICATE"]
ROOT -- PREDICATE0
EQ1 [label="EQ"]
PREDICATE0 -- EQ1
EQ1 -- "Q1.A1"
EQ1 -- "true"
PREDICATE0 -- "SHOW2 (Pointer(Q2))"

PREDICATE0 [label="PREDICATE"]
ROOT -- PREDICATE0
EQ1 [label="EQ"]
PREDICATE0 -- EQ1
EQ1 -- "Q1.A3"
EQ1 -- "false"
PREDICATE0 -- "HIDE2 (Pointer(Q3))"

ASSIGNMENT0 [label="ASSIGNMENT"]
ROOT -- ASSIGNMENT0
ASSIGNMENT0 -- "*(Q5.A1)"
ASSIGNMENT0 -- "3"

ASSIGNMENT0 [label="ASSIGNMENT"]
ROOT -- ASSIGNMENT0
ASSIGNMENT0 -- "*(Q5.A2)"
ASSIGNMENT0 -- "Q3.A2"

PREDICATE0 [label="PREDICATE"]
ROOT -- PREDICATE0
EQ1 [label="EQ"]
PREDICATE0 -- EQ1
EQ1 -- "Q5.A2"
EQ1 -- "Q5.A1"
ASSIGNMENT2 [label="ASSIGNMENT"]
PREDICATE0 -- ASSIGNMENT2
ASSIGNMENT2 -- "*(Q5.A3)"
ASSIGNMENT2 -- "10"

PREDICATE0 [label="PREDICATE"]
ROOT -- PREDICATE0
AND1 [label="AND"]
PREDICATE0 -- AND1
EQ2 [label="EQ"]
AND1 -- EQ2
EQ2 -- "Q5.A2"
EQ2 -- "Q5.A1"
OR3 [label="OR"]
AND1 -- OR3
EQ4 [label="EQ"]
OR3 -- EQ4
EQ4 -- "Q5.A3"
EQ4 -- "Q5.A4"
EQ5 [label="EQ"]
OR3 -- EQ5
EQ5 -- "Q5.A6"
EQ5 -- "Q5.A8"
ASSIGNMENT2 [label="ASSIGNMENT"]
PREDICATE0 -- ASSIGNMENT2
ASSIGNMENT2 -- "*(Q5.A3)"
ASSIGNMENT2 -- "10"

Run:

1. Install SBT from https://www.scala-sbt.org
2. Go to the project root folder
3. Run sbt run command from terminal