Data update

Task/Parsing-RPN-to-infix-conversion/Red/parsing-rpn-to-infix-conversion.red

@@ -0,0 +1,58 @@
+Red [ "RPN to Infix - Hinjo, 26 July 2025" ]
+
+rpn-to-infix: func [exp [string!]] [
+    blk: load exp ; convert into block
+    stack: copy []
+    stack-op: copy []
+
+    printstack: func [] [
+        foreach x stack [
+            prin rejoin [x " "]
+        ]
+    ]
+    push: func [val op] [
+        append stack val
+        append stack-op op
+    ]
+    pop: function [] [
+        val: take/last stack
+        op: take/last stack-op
+        compose [(val) (op)]
+    ]
+
+    foreach tok blk [
+        print rejoin [printstack]
+        case [
+            number? tok [push tok 'n]
+            find [+ - * / ^] tok [
+                b: pop
+                a: pop
+                if tok = '^ [
+                    if string? a/1 [
+                        if find "+-*/^^" a/2
+                            [a/1: rejoin ["(" a/1 ")"]]
+                    ]
+                    if string? b/1 [
+                        if find "+-*/" b/2
+                            [b/1: rejoin ["(" b/1 ")"]]
+                    ]
+                ]
+                if find "*/" tok [
+                    if string? a/1 [
+                        if find "+-" a/2
+                            [a/1: rejoin ["(" a/1 ")"]] ]
+                    if string? b/1 [
+                        if find "+-" b/2
+                            [b/1: rejoin ["(" b/1 ")"]] ] ]
+
+                expr: rejoin compose [""(rejoin [(a/1)" "(tok)" "(b/1)])""]
+                push expr tok
+            ]
+        ]
+    ]
+    printstack print ""
+]
+
+; in Red, "^" is an escape char, so, it must be written as ^^
+rpn-to-infix "3 4 2 * 1 5 - 2 3 ^^ ^^ / +"
+rpn-to-infix "1 2 + 3 4 + ^^ 5 6 + ^^"