Document hexadecimal support

Closes #15
#13

README.md

@@ -430,9 +430,9 @@ In addition, whitespace between tokens is ignored.
 
 Valid variable names consist of a letter or underscore followed by any combination
 of: letters `a`–`z` or `A`–`Z`, digits `0`–`9`, periods, and
-underscores. Constants can be integers, decimal numbers, or in scientific
-notation (e.g., `1e3` for `1000`). A leading zero is not required (e.g., `.5`
-for `0.5`).
+underscores. Constants can be integers or floating-point numbers, and can be in decimal,
+hexadecimal (e.g., `0x57CEF7`), or scientific notation (e.g., `1e3` for `1000`).
+A leading zero is not required (e.g., `.5` for `0.5`).
 
 ## Supported Functions
 

docs/manual/constants.qmd

@@ -5,9 +5,9 @@ The following mathematical and logical constants\index{constants} are available:
 ::: {.minipage data-latex="{\textwidth}"}
 | Constant | Value |
 | :------------- |:------------ |
-| E | Euler's number (`2.71828182845904523536`) |
+| E   | Euler's number (`2.71828182845904523536`) |
 | NAN | NaN (Not-a-Number) |
-| PI | pi (`3.14159265358979323846`) |
+| PI  | pi (`3.14159265358979323846`) |
 
 Table: Math Constants
 :::
@@ -19,7 +19,7 @@ If [`TE_FLOAT`](#te-float) is defined, then some precision for pi and Euler's nu
 ::: {.minipage data-latex="{\textwidth}"}
 | Constant | Value |
 | :------------- |:------------ |
-| TRUE | `1` |
+| TRUE  | `1` |
 | FALSE | `0` |
 
 Table: Logical Constants
@@ -30,7 +30,9 @@ The following number formats are supported:
 ::: {.minipage data-latex="{\textwidth}"}
 | Format | Example |
 | :------------- |:------------ |
-| Scientific notation\index{scientific notation} | `1e3` for `1000` |
+| Decimal | `5754615` or `3.14` |
+| Hexadecimal\index{hexadecimal} | `0x57CEF7`, which yields `5754615` |
+| Scientific notation\index{scientific notation} | `1e3`, which yields `1000` |
 
 Table: Number Formats
 :::

tests/tetests.cpp

@@ -757,6 +757,19 @@ TEST_CASE("Zeros", "[zeros]")
     CHECK(std::isnan(tep.evaluate("(1%0)%1")));
     }
 
+TEST_CASE("Hex", "[hex]")
+    {
+    te_parser tep;
+
+    CHECK(tep.evaluate("0x0") == 0);
+    CHECK(tep.evaluate("0x8") == 8);
+    CHECK(tep.evaluate("0x1FFFFFFFFFFFFF") == 9007199254740991);
+    CHECK(tep.evaluate("0x57CEF7") == 5754615);
+    CHECK(tep.evaluate("0x57CEF7") == 5754615);
+    CHECK(tep.evaluate("-0X57CEF7") == -5754615);
+    CHECK(std::isnan(tep.evaluate("0X")));
+    }
+
 TEST_CASE("UINT support", "[uint]")
     {
     te_parser tep;