Expression visitor (#122)

* Expression visitor

* Visit expressions in more intuitive order

* Better cache reuse in visitor/transformer

* Upgrade version to 0.5.5

Author: Saloed

README.md

@@ -11,7 +11,7 @@ Get the most out of SMT solving with KSMT features:
 * Streamlined [solver delivery](#ksmt-distribution) with no need for building a solver or implementing JVM bindings
 
 [![KSMT: build](https://github.com/UnitTestBot/ksmt/actions/workflows/build-and-run-tests.yml/badge.svg)](https://github.com/UnitTestBot/ksmt/actions/workflows/build-and-run-tests.yml)
-[![Maven Central](https://img.shields.io/maven-central/v/io.ksmt/ksmt-core)](https://central.sonatype.com/artifact/io.ksmt/ksmt-core/0.5.4)
+[![Maven Central](https://img.shields.io/maven-central/v/io.ksmt/ksmt-core)](https://central.sonatype.com/artifact/io.ksmt/ksmt-core/0.5.5)
 [![javadoc](https://javadoc.io/badge2/io.ksmt/ksmt-core/javadoc.svg)](https://javadoc.io/doc/io.ksmt/ksmt-core)
 
 ## Get started
@@ -20,9 +20,9 @@ To start using KSMT, install it via [Gradle](https://gradle.org/):
 
 ```kotlin
 // core 
-implementation("io.ksmt:ksmt-core:0.5.4")
+implementation("io.ksmt:ksmt-core:0.5.5")
 // z3 solver
-implementation("io.ksmt:ksmt-z3:0.5.4")
+implementation("io.ksmt:ksmt-z3:0.5.5")
 ```
 
 Find basic instructions in the [Getting started](docs/getting-started.md) guide and try it out with the 

buildSrc/src/main/kotlin/io.ksmt.ksmt-base.gradle.kts

@@ -11,7 +11,7 @@ plugins {
 }
 
 group = "io.ksmt"
-version = "0.5.4"
+version = "0.5.5"
 
 repositories {
     mavenCentral()

docs/getting-started.md

@@ -34,7 +34,7 @@ repositories {
 ```kotlin
 dependencies {
     // core 
-    implementation("io.ksmt:ksmt-core:0.5.4")    
+    implementation("io.ksmt:ksmt-core:0.5.5")    
 }
 ```
 
@@ -43,9 +43,9 @@ dependencies {
 ```kotlin
 dependencies {
     // z3 
-    implementation("io.ksmt:ksmt-z3:0.5.4")
+    implementation("io.ksmt:ksmt-z3:0.5.5")
     // bitwuzla
-    implementation("io.ksmt:ksmt-bitwuzla:0.5.4")
+    implementation("io.ksmt:ksmt-bitwuzla:0.5.5")
 }
 ```
 

examples/build.gradle.kts

@@ -9,11 +9,11 @@ repositories {
 
 dependencies {
     // core
-    implementation("io.ksmt:ksmt-core:0.5.4")
+    implementation("io.ksmt:ksmt-core:0.5.5")
     // z3 solver
-    implementation("io.ksmt:ksmt-z3:0.5.4")
+    implementation("io.ksmt:ksmt-z3:0.5.5")
     // Runner and portfolio solver
-    implementation("io.ksmt:ksmt-runner:0.5.4")
+    implementation("io.ksmt:ksmt-runner:0.5.5")
 }
 
 java {

ksmt-core/src/main/kotlin/io/ksmt/expr/transformer/KNonRecursiveTransformerBase.kt

@@ -35,16 +35,17 @@ abstract class KNonRecursiveTransformerBase: KTransformer {
      * Transform [expr] and all it sub-expressions non-recursively.
      * */
     override fun <T : KSort> apply(expr: KExpr<T>): KExpr<T> {
-        val cachedExpr = transformedExpr(expr)
-        if (cachedExpr != null) {
-            return cachedExpr
-        }
-
         val initialStackSize = exprStack.size
         try {
             exprStack.add(expr)
             while (exprStack.size > initialStackSize) {
                 val e = exprStack.removeLast()
+
+                val cachedExpr = transformedExpr(expr)
+                if (cachedExpr != null) {
+                    continue
+                }
+
                 exprWasTransformed = true
                 val transformedExpr = e.accept(this)