From d90d0ee08e9a2eae004604d0776090e213412dfc Mon Sep 17 00:00:00 2001
From: Fabian Homborg <FHomborg@gmail.com>
Date: Sun, 25 Feb 2018 21:41:38 +0100
Subject: [PATCH] [tinyexpr] Let specific errors take precedence over generic
 ones

Fixes the case where `sin()` reported the generic "bogus" error
instead of "too few arguments".

Also rename the constant to "TE_ERROR_UNKNOWN".
---
 src/builtin_math.cpp |  2 +-
 src/tinyexpr.c       | 25 ++++++++++++-------------
 src/tinyexpr.h       |  2 +-
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/src/builtin_math.cpp b/src/builtin_math.cpp
index fee462418..eb323294a 100644
--- a/src/builtin_math.cpp
+++ b/src/builtin_math.cpp
@@ -124,7 +124,7 @@ wcstring math_describe_error(te_error_t& error) {
         case TE_ERROR_TOO_FEW_ARGS: return _(L"Too few arguments");
         case TE_ERROR_TOO_MANY_ARGS: return _(L"Too many arguments");
         case TE_ERROR_MISSING_OPERATOR: return _(L"Missing operator");
-        case TE_ERROR_BOGUS: return _(L"Expression is bogus");
+        case TE_ERROR_UNKNOWN: return _(L"Expression is bogus");
         default: return L"";
     }
 }
diff --git a/src/tinyexpr.c b/src/tinyexpr.c
index 74aa9c47a..b91717706 100755
--- a/src/tinyexpr.c
+++ b/src/tinyexpr.c
@@ -239,8 +239,9 @@ void next_token(state *s) {
                             s->function = var->address;
                             break;
                     }
-                } else if (s->type != TOK_ERROR) {
-                    // TODO: Better error - "Not a variable"?
+                } else if (s->type != TOK_ERROR
+                           || s->error == TE_ERROR_UNKNOWN) {
+                    // Our error is more specific, so it takes precedence.
                     s->type = TOK_ERROR;
                     s->error = TE_ERROR_UNKNOWN_VARIABLE;
                 }
@@ -295,8 +296,8 @@ static te_expr *base(state *s) {
                 next_token(s);
                 if (s->type == TOK_CLOSE) {
                     next_token(s);
-                } else if (s->type != TOK_ERROR) {
-                    // TODO: Better error - "Missing closing parenthesis"?
+                } else if (s->type != TOK_ERROR
+                           || s->error == TE_ERROR_UNKNOWN) {
                     s->type = TOK_ERROR;
                     s->error = TE_ERROR_MISSING_CLOSING_PAREN;
                 }
@@ -323,15 +324,14 @@ static te_expr *base(state *s) {
                 }
                 if(s->type == TOK_CLOSE && i == arity - 1) {
                     next_token(s);
-                } else if (s->type != TOK_ERROR) {
-                    // TODO: Either a closing paren was needed,
-                    // or too few arguments were given?
+                } else if (s->type != TOK_ERROR
+                           || s->error == TE_ERROR_UNKNOWN) {
                     s->type = TOK_ERROR;
                     s->error = i < arity ? TE_ERROR_TOO_FEW_ARGS
                         : TE_ERROR_TOO_MANY_ARGS;
                 }
-            } else if (s->type != TOK_ERROR) {
-                // TODO: Better error - "Expected opening parenthesis"?
+            } else if (s->type != TOK_ERROR
+                       || s->error == TE_ERROR_UNKNOWN) {
                 s->type = TOK_ERROR;
                 s->error = TE_ERROR_MISSING_OPENING_PAREN;
             }
@@ -343,8 +343,8 @@ static te_expr *base(state *s) {
             ret = expr(s);
             if (s->type == TOK_CLOSE) {
                 next_token(s);
-            } else if (s->type != TOK_ERROR) {
-                // TODO: Error - missing closing paren?
+            } else if (s->type != TOK_ERROR
+                       || s->error == TE_ERROR_UNKNOWN) {
                 s->type = TOK_ERROR;
                 s->error = TE_ERROR_MISSING_CLOSING_PAREN;
             }
@@ -352,9 +352,8 @@ static te_expr *base(state *s) {
 
         default:
             ret = new_expr(0, 0);
-            // TODO: Error - expression is bogus?
             s->type = TOK_ERROR;
-            s->error = TE_ERROR_BOGUS;
+            s->error = TE_ERROR_UNKNOWN;
             ret->value = NAN;
             break;
     }
diff --git a/src/tinyexpr.h b/src/tinyexpr.h
index fc46ddc74..92319d595 100644
--- a/src/tinyexpr.h
+++ b/src/tinyexpr.h
@@ -41,7 +41,7 @@ extern "C" {
         TE_ERROR_TOO_FEW_ARGS = 4,
         TE_ERROR_TOO_MANY_ARGS = 5,
         TE_ERROR_MISSING_OPERATOR = 6,
-        TE_ERROR_BOGUS = 7
+        TE_ERROR_UNKNOWN = 7
     };
     typedef int te_error_type_t;