From 567beedfc8f6418e27259fa774e6c7ba1a685c22 Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Sat, 13 Aug 2022 19:16:11 -0600
Subject: parse: Fix a bug in the number parser

---
 parse.go | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

(limited to 'parse.go')

diff --git a/parse.go b/parse.go
index e09b85a..a1c5472 100644
--- a/parse.go
+++ b/parse.go
@@ -304,13 +304,27 @@ func (par *parser) stateInEscUC(c rune) (RuneType, error) {
 //        [-------------- integer ------------][--------- fraction --------][--------- exponent ---------]
 //     >─A─╮───────╭──╮─"0"─────────C─╭─────────╮──────────────────╭─────────╮──────────────────────────╭─>
 //         │       │  │               │         │                  │         │                          │
-//         ╰─"-"─B─╯  ╰─digit 1-9─╭─D─╯─digit╮  ╰─"."─E─digit──╭─F─╯─digit╮  ╰─"e"─╭─G─╮─────╭─╭digit─H─╯
-//                                ╰────<─────╯                 ╰────<─────╯  │     │   │     │ ╰────<───╯
+//         ╰─"-"─B─╯  ╰─digit 1-9─╭─D─╯─digit╮  ╰─"."─E─digit──╭─F─╯─digit╮  ╰─"e"─╭─G─╮─────╭─╭digit─I─╯
+//                                ╰────<─────╯                 ╰────<─────╯  │     │   │     H ╰────<───╯
 //                                                                           ╰─"E"─╯   ╰─"-"─╯
 //                                                                                     │     │
 //                                                                                     ╰─"+"─╯
 //
 // Which state we're at is the 'X' in 'stateNumberX'.
+//
+// It may be worth noting that these states, if we're going to try to
+// assign meaningful names, are perhaps best named by the type of the
+// preceding character:
+//
+//     A = (nothing yet)
+//     B = IntNeg
+//     C = IntZero
+//     D = IntDig
+//     E = FracDot
+//     F = FracDig
+//     G = ExpE
+//     H = ExpSign
+//     I = ExpDig
 
 // number: integer-part ////////////////////////////////////////////////////////
 func (par *parser) stateNumberA(c rune) (RuneType, error) { // start
@@ -395,14 +409,26 @@ func (par *parser) stateNumberF(c rune) (RuneType, error) { // in the fraction p
 // number: exponent-part ///////////////////////////////////////////////////////
 func (par *parser) stateNumberG(c rune) (RuneType, error) { // got a leading "e"
 	switch c {
-	case '-', '+', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+	case '-', '+':
 		par.replaceState(par.stateNumberH, true)
 		return RuneTypeNumberExp, nil
+	case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+		par.replaceState(par.stateNumberI, true)
+		return RuneTypeNumberExp, nil
+	default:
+		return RuneTypeError, fmt.Errorf("number: unexpected character: %c", c)
+	}
+}
+func (par *parser) stateNumberH(c rune) (RuneType, error) { // got a + or - sign
+	switch c {
+	case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+		par.replaceState(par.stateNumberI, true)
+		return RuneTypeNumberExp, nil
 	default:
 		return RuneTypeError, fmt.Errorf("number: unexpected character: %c", c)
 	}
 }
-func (par *parser) stateNumberH(c rune) (RuneType, error) { // in the exponent's number part
+func (par *parser) stateNumberI(c rune) (RuneType, error) { // in the exponent's number part
 	switch c {
 	case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
 		return RuneTypeNumberExp, nil
-- 
cgit v1.2.3-54-g00ecf