From 5c8bb47e119d2517b655336d5dbd7e65d74b0431 Mon Sep 17 00:00:00 2001
From: Astro <astro@spaceboyz.net>
Date: Wed, 9 Dec 2020 01:07:08 +0100
Subject: [PATCH] command_parser: require the explicit `i_set` symbol

---
 README.md             | 16 ++++++++--------
 src/command_parser.rs | 16 ++++++++++++----
 2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 58dd1d5..47d98be 100644
--- a/README.md
+++ b/README.md
@@ -75,7 +75,7 @@ The scope of this setting is per TCP session.
 | `pwm <0/1> max_i_pos <amp>`      | Set PWM duty cycle for **max_i_pos** to *ampere*    |
 | `pwm <0/1> max_i_neg <amp>`      | Set PWM duty cycle for **max_i_neg** to *ampere*    |
 | `pwm <0/1> max_v <volts>`        | Set PWM duty cycle for **max_v** to *volt*          |
-| `pwm <0/1> <amp>`                | Disengage PID, set **i_set** DAC to *ampere*        |
+| `pwm <0/1> i_set <amp>`          | Disengage PID, set **i_set** DAC to *ampere*        |
 | `pwm <0/1> pid`                  | Set PWM to be controlled by PID                     |
 | `center <0/1> <volts>`           | Set the MAX1968 0A-centerpoint to *volts*           |
 | `center <0/1> vref`              | Set the MAX1968 0A-centerpoint to measure from VREF |
@@ -146,12 +146,12 @@ output limits.
 
 Use the `pwm` command to see current settings and maximum values.
 
-| Limit       | Unit    | Description                             |
-| ---         | :---:   | ---                                     |
-| `max_v`     | Volts   | Maximum voltage                         |
-| `max_i_pos` | Amperes | Maximum positive current                |
-| `max_i_neg` | Amperes | Maximum negative current                |
-|             | Amperes | Output current control (Open-loop mode) |
+| Limit       | Unit    | Description                   |
+| ---         | :---:   | ---                           |
+| `max_v`     | Volts   | Maximum voltage               |
+| `max_i_pos` | Amperes | Maximum positive current      |
+| `max_i_neg` | Amperes | Maximum negative current      |
+| `i_set`     | Amperes | (Not a limit; Open-loop mode) |
 
 Example: set the maximum voltage of channel 0 to 1.5 V.
 ```
@@ -166,7 +166,7 @@ channel.
 
 Example: set output current of channel 0 to 0 A.
 ```
-pwm 0 0
+pwm 0 i_set 0
 ```
 
 ## PID-stabilized temperature control
diff --git a/src/command_parser.rs b/src/command_parser.rs
index 8cc7aa4..a71ddc4 100644
--- a/src/command_parser.rs
+++ b/src/command_parser.rs
@@ -249,6 +249,16 @@ fn pwm_setup(input: &[u8]) -> IResult<&[u8], Result<(PwmPin, f64), Error>> {
         result.map(|value| (pin, value));
 
     alt((
+        map(
+            preceded(
+                tag("i_set"),
+                preceded(
+                    whitespace,
+                    float
+                )
+            ),
+            result_with_pin(PwmPin::ISet)
+        ),
         map(
             preceded(
                 tag("max_i_pos"),
@@ -278,8 +288,6 @@ fn pwm_setup(input: &[u8]) -> IResult<&[u8], Result<(PwmPin, f64), Error>> {
                 )
             ),
             result_with_pin(PwmPin::MaxV)
-        ),
-        map(float, result_with_pin(PwmPin::ISet)
         ))
     )(input)
 }
@@ -528,8 +536,8 @@ mod test {
     }
 
     #[test]
-    fn parse_pwm_manual() {
-        let command = Command::parse(b"pwm 1 16383");
+    fn parse_pwm_i_set() {
+        let command = Command::parse(b"pwm 1 i_set 16383");
         assert_eq!(command, Ok(Command::Pwm {
             channel: 1,
             pin: PwmPin::ISet,