From 92a2ecbd8e58e0ed2f296e12737c99d6dcda652c Mon Sep 17 00:00:00 2001
From: hellerve <veit@veitheller.de>
Date: Mon, 30 Apr 2018 16:48:27 +0200
Subject: [PATCH] evaluator: add environment, make definitions work, add tests

---
 src/Phsyche.package/Phsyche.class/instance/eval..st    |  4 ++--
 src/Phsyche.package/Phsyche.class/instance/eval.in..st | 10 ++++++++--
 .../Phsyche.class/instance/evalDefine.in..st           |  5 +++++
 .../Phsyche.class/instance/initialize.st               |  4 ++++
 src/Phsyche.package/Phsyche.class/instance/parse..st   |  6 +++---
 .../Phsyche.class/instance/parseAndEval..st            |  4 ++--
 .../PhsycheTest.class/instance/testDefineExpression.st |  6 ++++++
 .../instance/testEvalExpressionReassignment.st         |  6 ++++++
 8 files changed, 36 insertions(+), 9 deletions(-)
 create mode 100644 src/Phsyche.package/Phsyche.class/instance/evalDefine.in..st
 create mode 100644 src/Phsyche.package/Phsyche.class/instance/initialize.st
 create mode 100644 src/Phsyche.package/PhsycheTest.class/instance/testDefineExpression.st
 create mode 100644 src/Phsyche.package/PhsycheTest.class/instance/testEvalExpressionReassignment.st

diff --git a/src/Phsyche.package/Phsyche.class/instance/eval..st b/src/Phsyche.package/Phsyche.class/instance/eval..st
index e86f908..a4e0db8 100644
--- a/src/Phsyche.package/Phsyche.class/instance/eval..st
+++ b/src/Phsyche.package/Phsyche.class/instance/eval..st
@@ -1,3 +1,3 @@
 as yet unclassified
-eval: expression
-	^ self eval: expression in: nil
\ No newline at end of file
+eval: expr
+	^ self eval: expr in: env
\ No newline at end of file
diff --git a/src/Phsyche.package/Phsyche.class/instance/eval.in..st b/src/Phsyche.package/Phsyche.class/instance/eval.in..st
index d563e43..6089db4 100644
--- a/src/Phsyche.package/Phsyche.class/instance/eval.in..st
+++ b/src/Phsyche.package/Phsyche.class/instance/eval.in..st
@@ -1,3 +1,9 @@
 as yet unclassified
-eval: expression in: anEnvironment
-	^ expression
\ No newline at end of file
+eval: expr in: environ
+	expr = #() ifTrue: [ ^ expr ].
+	expr isSymbol ifTrue: [ ^ environ at: expr ]. "returns the variable value"
+	expr isArray ifFalse: [ ^ expr ] "returns literals boolean, string, number"
+					 ifTrue: [
+						expr first = #define
+						ifTrue: [ ^ self evalDefine: expr in: environ ]
+					]
\ No newline at end of file
diff --git a/src/Phsyche.package/Phsyche.class/instance/evalDefine.in..st b/src/Phsyche.package/Phsyche.class/instance/evalDefine.in..st
new file mode 100644
index 0000000..2884d2e
--- /dev/null
+++ b/src/Phsyche.package/Phsyche.class/instance/evalDefine.in..st
@@ -0,0 +1,5 @@
+as yet unclassified
+evalDefine: expr in: environ
+	environ at: expr second
+			  put: (self eval: expr third in: environ).
+	^ #undefined
\ No newline at end of file
diff --git a/src/Phsyche.package/Phsyche.class/instance/initialize.st b/src/Phsyche.package/Phsyche.class/instance/initialize.st
new file mode 100644
index 0000000..42da799
--- /dev/null
+++ b/src/Phsyche.package/Phsyche.class/instance/initialize.st
@@ -0,0 +1,4 @@
+initialization
+initialize
+	super initialize.
+	env := Dictionary new
\ No newline at end of file
diff --git a/src/Phsyche.package/Phsyche.class/instance/parse..st b/src/Phsyche.package/Phsyche.class/instance/parse..st
index 27613f8..9a401a0 100644
--- a/src/Phsyche.package/Phsyche.class/instance/parse..st
+++ b/src/Phsyche.package/Phsyche.class/instance/parse..st
@@ -1,4 +1,4 @@
 as yet unclassified
-parse: aProgramString
-	aProgramString ifEmpty: [ ^ #() ].
-	^ (Scanner new scanTokens: aProgramString) first
\ No newline at end of file
+parse: prog
+	prog ifEmpty: [ ^ #() ].
+	^ (Scanner new scanTokens: prog) first
\ No newline at end of file
diff --git a/src/Phsyche.package/Phsyche.class/instance/parseAndEval..st b/src/Phsyche.package/Phsyche.class/instance/parseAndEval..st
index 7d85bf1..93ccf53 100644
--- a/src/Phsyche.package/Phsyche.class/instance/parseAndEval..st
+++ b/src/Phsyche.package/Phsyche.class/instance/parseAndEval..st
@@ -1,3 +1,3 @@
 as yet unclassified
-parseAndEval: anExpression
-	^ self eval: (self parse: anExpression)
\ No newline at end of file
+parseAndEval: expr
+	^ self eval: (self parse: expr)
\ No newline at end of file
diff --git a/src/Phsyche.package/PhsycheTest.class/instance/testDefineExpression.st b/src/Phsyche.package/PhsycheTest.class/instance/testDefineExpression.st
new file mode 100644
index 0000000..8f89216
--- /dev/null
+++ b/src/Phsyche.package/PhsycheTest.class/instance/testDefineExpression.st
@@ -0,0 +1,6 @@
+tests
+testDefineExpression
+	ph parseAndEval: '(define pi 3.14)'.
+	self
+		assert: (ph parseAndEval: 'pi')
+		equals: 3.14
\ No newline at end of file
diff --git a/src/Phsyche.package/PhsycheTest.class/instance/testEvalExpressionReassignment.st b/src/Phsyche.package/PhsycheTest.class/instance/testEvalExpressionReassignment.st
new file mode 100644
index 0000000..e0d81e4
--- /dev/null
+++ b/src/Phsyche.package/PhsycheTest.class/instance/testEvalExpressionReassignment.st
@@ -0,0 +1,6 @@
+tests
+testEvalExpressionReassignment
+	ph parseAndEval: '(define pi 3.14)'.
+	ph parseAndEval: '(define pi2 pi)'.
+	ph parseAndEval: '(define pi 6.28)'.
+	self assert: (ph parseAndEval: 'pi2') equals: 3.14
\ No newline at end of file