1 files changed, 99 insertions, 0 deletions
diff --git a/clap/src/completions/fish.rs b/clap/src/completions/fish.rs
new file mode 100644
index 0000000..c2c5a5e
--- /dev/null
+++ b/clap/src/completions/fish.rs
@@ -0,0 +1,99 @@
+// Std
+use std::io::Write;
+
+// Internal
+use app::parser::Parser;
+
+pub struct FishGen<'a, 'b>
+where
+    'a: 'b,
+{
+    p: &'b Parser<'a, 'b>,
+}
+
+impl<'a, 'b> FishGen<'a, 'b> {
+    pub fn new(p: &'b Parser<'a, 'b>) -> Self { FishGen { p: p } }
+
+    pub fn generate_to<W: Write>(&self, buf: &mut W) {
+        let command = self.p.meta.bin_name.as_ref().unwrap();
+        let mut buffer = String::new();
+        gen_fish_inner(command, self, command, &mut buffer);
+        w!(buf, buffer.as_bytes());
+    }
+}
+
+// Escape string inside single quotes
+fn escape_string(string: &str) -> String { string.replace("\\", "\\\\").replace("'", "\\'") }
+
+fn gen_fish_inner(root_command: &str, comp_gen: &FishGen, subcommand: &str, buffer: &mut String) {
+    debugln!("FishGen::gen_fish_inner;");
+    // example :
+    //
+    // complete
+    //      -c {command}
+    //      -d "{description}"
+    //      -s {short}
+    //      -l {long}
+    //      -a "{possible_arguments}"
+    //      -r # if require parameter
+    //      -f # don't use file completion
+    //      -n "__fish_use_subcommand"               # complete for command "myprog"
+    //      -n "__fish_seen_subcommand_from subcmd1" # complete for command "myprog subcmd1"
+
+    let mut basic_template = format!("complete -c {} -n ", root_command);
+    if root_command == subcommand {
+        basic_template.push_str("\"__fish_use_subcommand\"");
+    } else {
+        basic_template.push_str(format!("\"__fish_seen_subcommand_from {}\"", subcommand).as_str());
+    }
+
+    for option in comp_gen.p.opts() {
+        let mut template = basic_template.clone();
+        if let Some(data) = option.s.short {
+            template.push_str(format!(" -s {}", data).as_str());
+        }
+        if let Some(data) = option.s.long {
+            template.push_str(format!(" -l {}", data).as_str());
+        }
+        if let Some(data) = option.b.help {
+            template.push_str(format!(" -d '{}'", escape_string(data)).as_str());
+        }
+        if let Some(ref data) = option.v.possible_vals {
+            template.push_str(format!(" -r -f -a \"{}\"", data.join(" ")).as_str());
+        }
+        buffer.push_str(template.as_str());
+        buffer.push_str("\n");
+    }
+
+    for flag in comp_gen.p.flags() {
+        let mut template = basic_template.clone();
+        if let Some(data) = flag.s.short {
+            template.push_str(format!(" -s {}", data).as_str());
+        }
+        if let Some(data) = flag.s.long {
+            template.push_str(format!(" -l {}", data).as_str());
+        }
+        if let Some(data) = flag.b.help {
+            template.push_str(format!(" -d '{}'", escape_string(data)).as_str());
+        }
+        buffer.push_str(template.as_str());
+        buffer.push_str("\n");
+    }
+
+    for subcommand in &comp_gen.p.subcommands {
+        let mut template = basic_template.clone();
+        template.push_str(" -f");
+        template.push_str(format!(" -a \"{}\"", &subcommand.p.meta.name).as_str());
+        if let Some(data) = subcommand.p.meta.about {
+            template.push_str(format!(" -d '{}'", escape_string(data)).as_str())
+        }
+        buffer.push_str(template.as_str());
+        buffer.push_str("\n");
+    }
+
+    // generate options of subcommands
+    for subcommand in &comp_gen.p.subcommands {
+        let sub_comp_gen = FishGen::new(&subcommand.p);
+        gen_fish_inner(root_command, &sub_comp_gen, &subcommand.to_string(), buffer);
+    }
+}