From 1cb6e0704a1c4adc4d7ca7255585b154137b018f Mon Sep 17 00:00:00 2001
From: Rainer Kottenhoff <rainer.kottenhoff@gmail.com>
Date: Sun, 24 Jan 2021 13:57:57 +0100
Subject: [PATCH] + enh: Tinyexpr evaluation of math constants "e" and "pi" not
 being separated from prepending text

---
 src/Helpers.h           |  8 --------
 src/Notepad3.c          |  2 +-
 src/tinyexpr/tinyexpr.c |  1 +
 src/tinyexpr/tinyexpr.h | 44 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/src/Helpers.h b/src/Helpers.h
index 7ef52d282..c98e12ce8 100644
--- a/src/Helpers.h
+++ b/src/Helpers.h
@@ -720,14 +720,6 @@ inline bool IsAlphaNumericW(const WCHAR ch) {
         ((ch >= L'A') && (ch <= L'Z'));
 }
 
-// no encoding for safe chars
-inline bool IsIdentifierA(const char ch) {
-    return ((ch >= '0') && (ch <= '9')) ||
-           ((ch >= 'a') && (ch <= 'z')) ||
-           ((ch >= 'A') && (ch <= 'Z')) ||
-            (ch >= '_');
-}
-
 // If the character is an hexadecimal digit, get its value.
 inline int GetHexDigitA(const char ch)
 {
diff --git a/src/Notepad3.c b/src/Notepad3.c
index f1c7459cb..1e500fbe5 100644
--- a/src/Notepad3.c
+++ b/src/Notepad3.c
@@ -2131,7 +2131,7 @@ static bool _EvalTinyExpr(bool qmark)
             while (*pBegin && exprErr) {
                 dExprEval = te_interp(pBegin, &exprErr);
                 // proceed to next possible expression
-                while (exprErr && IsIdentifierA(*pBegin++)) {}
+                while (exprErr && !te_is_op(pBegin++)) {}
             }
             FreeMem(lineBuf);
 
diff --git a/src/tinyexpr/tinyexpr.c b/src/tinyexpr/tinyexpr.c
index 700632ce9..351ba9fef 100644
--- a/src/tinyexpr/tinyexpr.c
+++ b/src/tinyexpr/tinyexpr.c
@@ -454,6 +454,7 @@ void next_token(state *s) {
 
             } else {
                 /* Look for an operator or special character. */
+                /* keep in sync with te_isop(const char ch) defined in header */
                 switch (s->next++[0]) {
                     case '+': s->type = TOK_INFIX; s->function = get_function_pointer_2d(add); break;
                     case '-': s->type = TOK_INFIX; s->function = get_function_pointer_2d(sub); break;
diff --git a/src/tinyexpr/tinyexpr.h b/src/tinyexpr/tinyexpr.h
index 8e74c17d0..fad777a67 100644
--- a/src/tinyexpr/tinyexpr.h
+++ b/src/tinyexpr/tinyexpr.h
@@ -105,6 +105,50 @@ void te_print(const te_expr *n);
 /* This is safe to call on NULL pointers. */
 void te_free(te_expr *n);
 
+/* check for operator or special character. */
+inline int te_is_op(const char* const expr) {
+    if (!expr)
+        return !0;
+    switch (*expr) {
+    case 0:
+    case '+':
+    case '-':
+    case '*':
+    case -41:
+    case '/':
+    case ':':
+    case -9:
+    case '^':
+    case '%':
+    case '!':
+    case '<':
+    case '>':
+    case '(':
+    case ')':
+    case ',':
+    case ' ':
+    case '\t':
+    case '\n':
+    case '\r':
+        return !0;
+    case '=':
+        if (expr[1] == '=')
+            return !0;
+        break;
+    case '&':
+        if (expr[1] == '&')
+            return !0;
+        break;
+    case '|':
+        if (expr[1] == '|')
+            return !0;
+        break;
+    default:
+        break;        
+    }
+    return 0;
+}
+
 
 #ifdef __cplusplus
 }