From f594027de5eedcd757cdc2b647b6bbe70a666115 Mon Sep 17 00:00:00 2001
From: Peter Smit <peter@elnino.tech>
Date: Wed, 6 Dec 2023 15:16:07 +0100
Subject: [PATCH] Functions v0.1

---
 IBAF-cbs/IBAF/IBAF-Start/IBAF-Expressions.cbs |  2 ++
 IBAF-cbs/IBAF/IBAF-Start/IBAF-Statements.cbs  | 10 ++++++++++
 2 files changed, 12 insertions(+)

diff --git a/IBAF-cbs/IBAF/IBAF-Start/IBAF-Expressions.cbs b/IBAF-cbs/IBAF/IBAF-Start/IBAF-Expressions.cbs
index c8c5ac1..42bf953 100644
--- a/IBAF-cbs/IBAF/IBAF-Start/IBAF-Expressions.cbs
+++ b/IBAF-cbs/IBAF/IBAF-Start/IBAF-Expressions.cbs
@@ -17,6 +17,7 @@ Syntax Exp:exp ::= id
                  | exp '>' exp
                  | exp '<=' exp
                  | exp '<' exp
+                 | id '(' ')'
                  | '(' exp ')'
 
 Semantics eval-exp[[ _:exp ]] : => values
@@ -36,6 +37,7 @@ Rule eval-exp[[ Exp1 '>=' Exp2 ]] = is-greater-or-equal(eval-exp[[ Exp1 ]], eval
 Rule eval-exp[[ Exp1 '>' Exp2 ]] = is-greater(eval-exp[[ Exp1 ]], eval-exp[[ Exp2]] )
 Rule eval-exp[[ Exp1 '<=' Exp2 ]] = is-less-or-equal(eval-exp[[ Exp1 ]], eval-exp[[ Exp2]] )
 Rule eval-exp[[ Exp1 '<' Exp2 ]] = is-less(eval-exp[[ Exp1 ]], eval-exp[[ Exp2]] )
+Rule eval-exp[[ Id '(' ')' ]] = enact id[[ Id ]]
 Rule eval-exp[[ '(' Exp ')' ]] = eval-exp[[ Exp ]]
 
 
diff --git a/IBAF-cbs/IBAF/IBAF-Start/IBAF-Statements.cbs b/IBAF-cbs/IBAF/IBAF-Start/IBAF-Statements.cbs
index 3541d7f..ea785b0 100644
--- a/IBAF-cbs/IBAF/IBAF-Start/IBAF-Statements.cbs
+++ b/IBAF-cbs/IBAF/IBAF-Start/IBAF-Statements.cbs
@@ -7,6 +7,8 @@ Syntax Stmt: statement ::= '{' statement* '}'
                     | type id ';'
                     | type id '=' exp ';'
                     | id '=' exp ';'
+                    | 'return' exp? ';'
+                    | 'fun' id '(' ')' '{' statement* '}'
 
 Syntax Typ:type ::= 'int'
                    | 'bool'
@@ -20,6 +22,9 @@ Rule execute[[ 'print' '(' Exp ')' ';' ]] = print eval-exp[[ Exp ]]
 Rule execute[[ Typ Id ';' ]] = null
 Rule execute[[ Typ Id '=' Exp ';' ]] = assign(bound id[[ Id ]], eval-exp[[ Exp ]])
 Rule execute[[ Id '=' Exp ';' ]] = assign(bound id[[ Id ]], eval-exp[[ Exp ]])
+Rule execute[[ 'return' Exp ';' ]] = return exal-exp[[ Exp ]]
+Rule execute[[ 'return' ';' ]] = return null
+Rule execute[[ 'fun' Id '(' ')' '{' Stmt* '}' ]] = null
 
 Rule execute[[ ]] = null
 Rule execute[[ Stmt Stmt+ ]] = sequential(execute[[ Stmt ]], execute[[ Stmt+ ]])
@@ -47,6 +52,11 @@ Rule collect-declared-vars[[ Typ Id ';' ]] =
             0 //TODO: use correct default value for type
         )
     )
+Rule collect-declared-vars[[ 'fun' Id '(' ')' '{' Stmt* '}' ]] = 
+  bind(
+    \"Id\", 
+    handle-return function abstraction execute[[ '{' Stmt* '}' ]]
+  )
 Rule collect-declared-vars[[ ]] = map()
 Rule collect-declared-vars[[ Stmt ]] = map()
 Rule collect-declared-vars[[ Stmt1 Stmt2 Stmt* ]] = collect-declared-vars[[ Stmt1 ]], collect-declared-vars[[ Stmt2 ]], collect-declared-vars[[ Stmt* ]]