add ps and early help

crates/nu-protocol/src/ast/call.rs

@@ -35,4 +35,14 @@ impl Call {
 
         false
     }
+
+    pub fn get_flag_expr(&self, flag_name: &str) -> Option<Expression> {
+        for name in &self.named {
+            if flag_name == name.0 {
+                return name.1.clone();
+            }
+        }
+
+        None
+    }
 }

crates/nu-protocol/src/engine/engine_state.rs

@@ -1,5 +1,5 @@
 use super::Command;
-use crate::{ast::Block, BlockId, DeclId, Span, Type, VarId};
+use crate::{ast::Block, BlockId, DeclId, Signature, Span, Type, VarId};
 use core::panic;
 use std::{collections::HashMap, slice::Iter};
 
@@ -164,6 +164,21 @@ impl EngineState {
             .expect("internal error: missing declaration")
     }
 
+    pub fn get_decls(&self) -> Vec<Signature> {
+        let mut output = vec![];
+        for decl in self.decls.iter() {
+            if decl.get_block_id().is_none() {
+                let mut signature = (*decl).signature();
+                signature.usage = decl.usage().to_string();
+                signature.extra_usage = decl.extra_usage().to_string();
+
+                output.push(signature);
+            }
+        }
+
+        output
+    }
+
     pub fn get_block(&self, block_id: BlockId) -> &Block {
         self.blocks
             .get(block_id)

crates/nu-protocol/src/engine/evaluation_context.rs

@@ -1,7 +1,7 @@
 use super::EngineState;
 use std::{cell::RefCell, collections::HashMap, rc::Rc};
 
-use crate::{ShellError, Value, VarId};
+use crate::{ShellError, Signature, Value, VarId};
 
 #[derive(Clone)]
 pub struct EvaluationContext {
@@ -46,6 +46,10 @@ impl EvaluationContext {
     pub fn print_stack(&self) {
         self.stack.print_stack();
     }
+
+    pub fn get_commands_info(&self) -> Vec<Signature> {
+        self.engine_state.borrow().get_decls()
+    }
 }
 
 #[derive(Debug)]

crates/nu-protocol/src/shell_error.rs

@@ -74,4 +74,8 @@ pub enum ShellError {
     #[error("Unsupported input")]
     #[diagnostic(code(nu::shell::unsupported_input), url(docsrs))]
     UnsupportedInput(String, #[label("{0}")] Span),
+
+    #[error("Flag not found")]
+    #[diagnostic(code(nu::shell::flag_not_found), url(docsrs))]
+    FlagNotFound(String, #[label("{0} not found")] Span),
 }

crates/nu-protocol/src/span.rs

@@ -1,6 +1,11 @@
 use miette::SourceSpan;
 use serde::{Deserialize, Serialize};
 
+pub struct Spanned<T> {
+    pub item: T,
+    pub span: Span,
+}
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub struct Span {
     pub start: usize,

crates/nu-protocol/src/value/mod.rs

@@ -29,6 +29,10 @@ pub enum Value {
         val: u64,
         span: Span,
     },
+    Duration {
+        val: u64,
+        span: Span,
+    },
     Range {
         val: Box<Range>,
         span: Span,
@@ -86,6 +90,7 @@ impl Value {
             Value::Int { span, .. } => *span,
             Value::Float { span, .. } => *span,
             Value::Filesize { span, .. } => *span,
+            Value::Duration { span, .. } => *span,
             Value::Range { span, .. } => *span,
             Value::String { span, .. } => *span,
             Value::Record { span, .. } => *span,
@@ -104,6 +109,7 @@ impl Value {
             Value::Int { span, .. } => *span = new_span,
             Value::Float { span, .. } => *span = new_span,
             Value::Filesize { span, .. } => *span = new_span,
+            Value::Duration { span, .. } => *span = new_span,
             Value::Range { span, .. } => *span = new_span,
             Value::String { span, .. } => *span = new_span,
             Value::Record { span, .. } => *span = new_span,
@@ -125,6 +131,7 @@ impl Value {
             Value::Int { .. } => Type::Int,
             Value::Float { .. } => Type::Float,
             Value::Filesize { .. } => Type::Filesize,
+            Value::Duration { .. } => Type::Duration,
             Value::Range { .. } => Type::Range,
             Value::String { .. } => Type::String,
             Value::Record { cols, vals, .. } => {
@@ -146,6 +153,7 @@ impl Value {
             Value::Int { val, .. } => val.to_string(),
             Value::Float { val, .. } => val.to_string(),
             Value::Filesize { val, .. } => format!("{} bytes", val),
+            Value::Duration { val, .. } => format!("{} ns", val),
             Value::Range { val, .. } => {
                 format!(
                     "range: [{}]",
@@ -185,6 +193,7 @@ impl Value {
             Value::Int { val, .. } => val.to_string(),
             Value::Float { val, .. } => val.to_string(),
             Value::Filesize { val, .. } => format!("{} bytes", val),
+            Value::Duration { val, .. } => format!("{} ns", val),
             Value::Range { val, .. } => val
                 .into_iter()
                 .map(|x| x.into_string())